KR20230158334A - Catalyst system including selenium and amino pyridine derivative for preparing dialkyl carbonate derivative and method of preparing dialkyl carbonate derivative using same - Google Patents

Abstract

The present invention relates to selenium (Se); and a pyridine amine compound represented by the following structural formula 1. It relates to a catalyst system for producing a carbonate derivative comprising: The catalyst system for producing carbonate derivatives of the present invention and the method for producing carbonate derivatives using the same are economical and economical compared to existing carbonylation processes by carrying out the oxidative carbonylation process of alcohol using a selenium-based catalyst system containing a pyridine amine compound. , dialkyl carbonate can be obtained in feasible yield.
[Structural Formula 1]

In structural formula 1,
n is an integer from 1 to 4.

Description

Selenium and amino pyridine compound catalyst system for producing dialkyl carbonate derivatives and method for producing carbonate derivatives using the same

The present invention relates to a catalyst system for producing carbonate derivatives and a method for producing carbonate derivatives using the same. More specifically, it relates to a selenium and amino pyridine compound catalyst system for producing dialkyl carbonate derivatives and a method for producing carbonate derivatives using the same. will be.

Dialkyl carbonates (DAC) are attracting attention because they have environmentally benign characteristics and can be used in a variety of applications such as aprotic solvents, monomers for polycarbonate, and alkylating agents. Additionally, dialkyl carbonate is also used as an electrolyte solvent and gasoline additive. These dialkyl carbonates can be easily produced through the reaction of alcohol and phosgene.

However, the phosgenation reaction causes problems due to the use of highly toxic phosgene. To replace this phosgenation reaction, several processes have been developed, including transesterification, methyl nitrile carbonylation, alcoholysis of urea, oxidative carbonylation, and carboxylation. Among these, the synthesis of DAC through carboxylation with CO ₂ is the most preferable from environmental and economic perspectives, but an economically feasible process using CO ₂ as a raw material has not yet been developed. Additionally, the above reaction has problems such as generation of by-products during the reaction and complicated processes.

Meanwhile, a method of producing dimethyl carbonate through oxidative carbonylation using a copper-based catalyst such as CuCl has been commercialized by Enichem (see US Patent 5,536,864). Since then, many efforts have been made to improve the activity of copper-based catalysts. A successful example is the use of PdCl ₂ and ammonium salts with CuCl ₂ . Dow chemical has also issued several patents for the use of activated carbon-supported copper catalysts (see US Patent 5,004,827, US Patent 4,625,044).

Nevertheless, the catalyst systems reported so far for oxidative carbonylation reactions still require improvement in terms of activity, selectivity, and catalyst recovery and corrosion.

U.S. Patent Registration No. 5,536,864 U.S. Patent Registration No. 5,004,827 U.S. Patent Registration No. 4,625,044

The object of the present invention is to carry out the oxidative carbonylation process of alcohol using a selenium-based catalyst system containing a pyridine amine compound, thereby producing dialkyl carbonate or dialkoxyl carbonate in a more economical and feasible high yield compared to the existing carbonylation process. The object is to provide a catalyst system capable of obtaining carbonate derivatives such as alkyl carbonates and a method for producing carbonate derivatives using the same.

Another object of the present invention is to provide a catalyst system for producing carbonate derivatives that can maintain activity even if reused multiple times by using a selenium-based catalyst system, and a method for producing carbonate derivatives using the same.

According to one aspect of the present invention, selenium (Se); and a pyridine amine compound represented by the following structural formula 1. A catalyst system for producing a carbonate derivative is provided, including:

[Structural Formula 1]

In structural formula 1,

n is an integer from 1 to 4.

The pyridine amine compound may be any one selected from the group consisting of 4-piperidinopyridine (PPP) and 4-pyrrolidinopyridine (PPY).

The catalyst system may have a molar ratio (PA/Se) of the pyridine amine compound (PA) to the selenium (Se) of 1 to 6.

The catalyst system may further include a promoter.

The accelerator may be for generating selenium nanoparticles.

The accelerator is a group consisting of diphenyl diselenide (Ph ₂ Se ₂ ), dimethyl diselenide (Me ₂ Se ₂ ), dibenzyl diselenide (Bz ₂ Se ₂ ) and diphenyl selenide (Ph ₂ Se). It may include one or more types selected from.

The accelerator may include diphenyldiselenide (Ph ₂ Se ₂ ).

The catalyst system may have a molar ratio of the promoter to selenium (Se) (promoter/Se) of 0.00016 to 0.64.

The carbonate derivative may be a compound represented by structural formula 2 below.

[Structural Formula 2]

In structural formula 2,

R ³ is each independently a C1 to C6 alkylene group,

R ⁴ is each independently a hydrogen atom or ego,

R ⁵ is each independently a C1 to C3 alkyl group.

The carbonate derivative may be bis(2-methoxyethyl) carbonate (BMEC).

The selenium may have a nanoparticle or bulk shape.

The nanoparticle shape may have a size of 10 to 1,000 nm.

The bulk features can be greater than 1 μm and less than 50 μm in size.

According to another aspect of the present invention, in Scheme 1, a method for producing a carbonate derivative includes the step of preparing compound 2 by reacting reactants containing compound 3, carbon monoxide, and oxygen using a catalyst system as shown in Scheme 1. provided.

[Scheme 1]

In Scheme 1 above,

R ³ is each independently a C1 to C6 alkylene group,

R ⁴ is each independently a hydrogen atom or ego,

R ⁵ is each independently a C1 to C3 alkyl group.

The catalyst system includes selenium (Se); and a pyridine amine compound represented by the following structural formula 1.

[Structural Formula 1]

In structural formula 1,

n is an integer from 1 to 4.

The pyridine amine compound may be any one selected from the group consisting of 4-piperidinopyridine (PPP) and 4-pyrrolidinopyridine (PPY).

The catalyst system may further include a promoter.

The accelerator is a group consisting of diphenyl diselenide (Ph ₂ Se ₂ ), dimethyl diselenide (Me ₂ Se ₂ ), dibenzyl diselenide (Bz ₂ Se ₂ ) and diphenyl selenide (Ph ₂ Se). It may include one or more types selected from.

The accelerator may include diphenyldiselenide (Ph ₂ Se ₂ ).

The reaction may be performed at 10 to 150°C.

The catalyst system for producing carbonate derivatives of the present invention and the method for producing carbonate derivatives using the same are economical and economical compared to existing carbonylation processes by carrying out the oxidative carbonylation process of alcohol using a selenium-based catalyst system containing a pyridine amine compound. , dialkyl carbonate can be obtained in a feasible high yield.

In addition, the catalyst system for producing carbonate derivatives of the present invention and the method for producing carbonate derivatives using the same have the effect of maintaining catalytic activity even if reused several times by using a selenium-based catalyst system.

In addition, existing CuCl or CuCl _2- based catalyst systems contain halogen elements and cause reactor corrosion, whereas selenium-based catalyst systems do not cause this problem.

Figure 1 is a 1H NMR graph of purified BMEC obtained using a catalyst system containing 4-pyrrolidinopyridine (PPY).
Figure 2a shows the results of the reuse evaluation of the Se/Ph ₂ Se ₂ /DMAP catalyst system, and Figures 2b to 2d show the Se recovered from the reaction carried out in the absence of Ph ₂ Se ₂ , DMAP recovered after the first run, and the 5th run. This is a FE-SEM image of DMAP recovered afterward. Additionally, Figures 2e to 2g show 1H NMR spectra of purified Ph ₂ Se ₂ , DMAP, and BMEC.
Figure 3a shows the ATR-FTIR spectra of MEG, activated Se, and DMAP at 50°C, CO/O ₂ (CO/O ₂ = 7/3, 6.12 MPa), and Figure 3b shows the ATR-FTIR spectra at 50°C, CO ( ATR-FTIR spectra (green lines) of MEG, activated Se, and DMAP at 4.28 MPa), 50°C, addition of O ₂ (CO/O ₂ = 7/3, 6.12 MPa), Se (activated Se), This is the ATR-FTIR spectra of DMAP. Figure 3c is also an ATR-FTIR spectra of the solid obtained from the overnight reaction of MEG, activated Se, and DMAP at 50°C under a CO atmosphere (6.12 MPa).
Figure 4a is a relative energy diagram for the Se/DMAP catalyzed reaction to identify the key role of DMAP, and Figure 4b is the oxidative carbonylation reaction mechanism of alcohol to produce DAC.
Figure 5 is a FE-SEM image of selenium recovered in reactions carried out with catalyst systems according to various promoters, (a) Se/Ph ₂ Se ₂ /PPY = 1/0.08/5 (Example 41), (b) ) is Se/Me ₂ Se ₂ /PPY = 1/0.08/5 (Example 42), (c) Se/Bz ₂ Se ₂ /PPY = 1/0.08/5 (Example 43).

Since the present invention can be subject to various changes in reaction conditions and can have various embodiments, specific embodiments will be exemplified and explained in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all transformations, equivalents, and substitutes included in the spirit and technical scope of the present invention. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

Additionally, terms including ordinal numbers, such as first, second, etc., which will be used below, may be used to describe various components, but the components are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component, and similarly, the second component may also be named a first component without departing from the scope of the present invention.

Additionally, when a component is referred to as being “on another component,” “formed on another component,” “located on another component,” or “stacked on another component,” It may be formed by being directly attached to the front or one side of the surface of another component, positioned, or stacked, but it should be understood that other components may further exist in the middle.

Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, the catalyst system for producing carbonate derivatives of the present invention will be described.

The present invention relates to selenium (Se); and a pyridine amine compound represented by Structural Formula 1 below.

[Structural Formula 1]

In structural formula 1,

n is an integer from 1 to 4, and is preferably 1 or 2.

The pyridine amine compound may be any one selected from the group consisting of 4-piperidinopyridine (PPP) and 4-pyrrolidinopyridine (PPY).

The catalyst system may have a molar ratio (PA/Se) of the pyridine amine compound (PA) to selenium (Se) of 1 to 6, preferably 4 to 6. If the molar ratio (PAC/Se) of the pyridine amine compound (PA) to selenium (Se) is less than 1, the yield is low and thus undesirable, and if it is greater than 6, the yield is somewhat low and thus undesirable.

The catalyst system may further include a promoter.

The accelerator may be for generating selenium nanoparticles.

The accelerator is a group consisting of diphenyl diselenide (Ph ₂ Se ₂ ), dimethyl diselenide (Me ₂ Se ₂ ), dibenzyl diselenide (Bz ₂ Se ₂ ) and diphenyl selenide (Ph ₂ Se). It may include one or more types selected from, and preferably includes diphenyldiselenide (Ph ₂ Se ₂ ).

In the catalyst system, the molar ratio of the promoter to selenium (Se) (promoter/Se) may be 0.00016 to 0.64, preferably 0.04 to 0.32, and more preferably 0.08.

The carbonate derivative may be a compound represented by structural formula 2 below.

[Structural Formula 2]

In structural formula 2,

R ³ is each independently a C1 to C6 alkylene group,

R ⁴ is each independently a hydrogen atom or ego,

R ⁵ is each independently a C1 to C3 alkyl group.

Preferably, in structural formula 2, R ³ is each independently a C1 to C4 alkylene group.

The carbonate derivative may be bis(2-methoxyethyl) carbonate (BMEC).

The selenium may have a nanoparticle or bulk shape.

The nanoparticle shape may have a size of 10 to 1,000 nm.

The bulk features can be greater than 1 μm and less than 50 μm in size.

The catalyst system contains 0.5 to 2 mol% of selenium; The diphenyldiselenide (Ph ₂ Se ₂ ) is 0.00016 to 0.64 equivalents relative to the selenium; And the pyridine amine compound may include 1 to 5 equivalents relative to the selenium.

In addition, the present invention provides a method for producing a carbonate derivative, which includes the step of preparing compound 2 by reacting reactants including compound 3, carbon monoxide, and oxygen using a catalyst system as shown in reaction formula 1.

[Scheme 1]

In Scheme 1 above,

R ³ is each independently a C1 to C6 alkylene group,

R ⁴ is each independently a hydrogen atom or ego,

R ⁵ is each independently a C1 to C3 alkyl group.

The catalyst system includes selenium (Se); and a pyridine amine compound represented by the following structural formula 1.

[Structural Formula 1]

In structural formula 1,

n is an integer from 1 to 4.

The pyridine amine compound may be any one selected from the group consisting of 4-piperidinopyridine (PPP) and 4-pyrrolidinopyridine (PPY).

The catalyst system may further include a promoter.

The accelerator is a group consisting of diphenyl diselenide (Ph ₂ Se ₂ ), dimethyl diselenide (Me ₂ Se ₂ ), dibenzyl diselenide (Bz ₂ Se ₂ ) and diphenyl selenide (Ph ₂ Se). It may include one or more types selected from, and preferably includes diphenyldiselenide (Ph ₂ Se ₂ ).

In Scheme 1, Compound 3 may include 2-methoxyethanol (MEG).

The reaction may be carried out at a temperature of 10 to 150°C, preferably at a temperature of 30 to 120°C, and more preferably at a temperature of 50 to 100°C. If the reaction is performed at a temperature below 10°C, it is undesirable because the BMEC yield is low, and if the reaction is performed at a temperature above 150°C, by-products increase, which is undesirable.

The reaction may be performed at a pressure of 1 to 10 MPa, preferably at a pressure of 3 to 8 MPa, and more preferably at a pressure of 5 to 7 MPa. If the reaction is performed at a pressure of less than 1 MPa, the BMEC yield is low, which is undesirable, and if the reaction is performed at a pressure of more than 10 MPa, by-products increase, which is undesirable.

The reaction may be performed for 30 minutes to 5 hours, preferably for 40 minutes to 3 hours, and more preferably for 50 minutes to 2 hours. If the reaction is performed for less than 30 minutes, it is undesirable because the BMEC yield is low, and if it is performed for more than 4 hours, it is undesirable because by-products increase.

In Scheme 1, the volume ratio (O ₂ /CO, v/v) of carbon monoxide (CO) and oxygen (O ₂ ) may be 0.01 to 1, preferably 0.1 to 0.3, and more preferably It may be 0.2 to 0.3. If the oxygen partial pressure exceeds 30%, there may be a risk of explosion.

Dialkyl carbonate can be produced through an oxidative carbonylation process of alcohol in the presence of the catalyst system for producing carbonate derivatives according to the present invention, and the above reaction can be performed continuously in a reactor.

When carrying out the oxidative carbonylation of alcohols in the presence of the catalyst system according to the invention, the catalyst systems are converted to elemental selenium and PPP or PPY, thereby producing bis(2-methoxyethyl) carbonate. carbonate) can be produced at an economically feasible yield compared to existing carbonylation processes.

[Example]

Hereinafter, the present invention will be described in more detail through examples. However, this is for illustrative purposes only and does not limit the scope of the present invention.

[Raw material]

Selenium (99.9%, 200 mesh), DMAP (+98%), and MEG (98%) were purchased from Alfa Aesar (USA), and other chemicals were purchased from Sigma-Aldrich (USA). Additionally, CO and O ₂ (99.95% purity) were obtained from Gong-Dan Industrial Gas Co (South Korea). All chemicals were used without further purification. Unless otherwise specified in this specification, mesh means that Selenium is in bulk form.

[Catalyst activity experiment]

All experiments were performed in a 50 mL stainless steel reactor equipped with a magnetic stirrer, thermocouple, and electric heater. Appropriate alcohol, Se, Ph ₂ Se ₂ and DMAP were added to the reactor. Subsequently, the reactor was washed three times, pressurized with CO/O ₂ (7/3) mixed gas at room temperature, and heated to 50, 70, or 90° C. while vigorously stirring. The reactor was further pressurized to 6.12 MPa and these conditions were maintained throughout the reaction using a gas reservoir equipped with a high pressure regulator and pressure transducer. The conversion of alcohol and the yield of DAC were analyzed using an Agilent 6890 gas chromatograph (Agilent Technologies, USA) equipped with an HP-5 capillary column and flame ionization detector (FID), and the selectivity of DAC and alkylated Se species was determined by methyl 1H NMR analysis was performed using benzoate as an internal standard. The conversion rate of alcohol along with the yield and selectivity of DAC were obtained by GC-FID and calculated using Equations 1 to 3 below.

[Equation 1]

[Equation 2]

[Equation 3]

[Manufacture of selenium nanoparticles (SeNPs)]

Preparation Examples 1-1 and 1-2: Use of DMSO

The reaction was carried out according to Scheme 2 below in a 50 mL stainless steel reactor equipped with a magnetic stirrer, thermocouple and electric heater. DMSO (30 mL) and Se (200 mesh, 0.3 g) were added to the reactor with or without Ph ₂ Se ₂ (95 mg). The reactor was then washed three times, pressurized with CO gas at room temperature, and heated to 90° C. with vigorous stirring. The reactor was further pressurized to 6.12 MPa and these conditions were maintained throughout the reaction using a gas reservoir equipped with a high pressure regulator and pressure transducer. After the reaction, acetone was added to the resulting black solution to precipitate selenium nanoparticles (SeNP), and then centrifuged at 900 rpm for 5 minutes to collect SeNP. The obtained SeNPs were washed three times with acetone and dried under vacuum. The composition and catalytic activity for preparing selenium nanoparticles using DMSO are listed in Table 1 below.

Preparation Examples 2-1 and 2-2: Use of MEG

The reaction was performed according to Scheme 2 below in a 50 mL stainless steel reactor equipped with a magnetic stirrer, thermocouple, and electric heater. MEG (28.9 g) and Se (200 mesh, 0.3 g) were added to the reactor with or without Ph ₂ Se ₂ (95 mg). The reactor was then washed three times, pressurized with CO gas at room temperature, and heated to 90° C. with vigorous stirring. The reactor was further pressurized to 6.12 MPa and these conditions were maintained throughout the reaction using a gas reservoir equipped with a high pressure regulator and pressure transducer. After the reaction, a clear bright yellow (with Ph ₂ Se ₂ , Preparation Example 2-1) or brownish yellow (without Ph ₂ Se ₂ , Preparation Example 2-2) solution (in-situ generated SeNPs in MEG) was obtained. The composition and catalytic activity for preparing selenium nanoparticles using MEG are listed in Table 1 below.

[Scheme 2]

Se pretreatment methods Size of Se
(nm) BMEC Yield (%) TOF
(h ^-1 ) Method Solvent Additive Manufacturing Example 1-1 DMSO Ph ₂ Se ₂ ca. 60 55.9 ^27.8a Manufacturing Example 1-2 DMSO - ca. 340 53.9 ^26.4a Manufacturing Example 2-1 MEG Ph ₂ Se ₂ ca. 410 50.2 25.7 ^b Manufacturing Example 2-2 MEG - ca. 490 42.1 ^22.3b

a) Oxidative carbonylation of MEG using SeNPs (59 mg, 0.75 mmol) and DMAP (3.75 mmol) recovered from MEG (75 mmol) as reactants and solvents, n(MEG/SeNPs/DMAP) = 100/1/ 5, carried out under conditions of T = 50°C, P = 6.12 MPa (CO/O ₂ = 7/3), t = 1 hb) Oxidative carbonylation of MEG with or without Ph ₂ Se ₂ (0.06 mmol) MEG solution containing in situ generated SeNPs [initial amount of Se: 59 mg (0.75 mmol); MEG: 75 mmol] and DMAP (3.75 mmol), n(MEG/Se/Ph ₂ Se ₂ /DMAP) = 100/1/0.08/5 or n(MEG/Se/DMAP) = 100/1/ 5, conducted at T = 50℃, P = 6.12MPa (CO/O2 = 7/3), t = 1h

[Catalyst system]

Examples 1 to 8

Catalysts of Examples 1 to 8 with different compositions and molar ratios of the catalyst system using MEG (75 mmol), Se (200 mesh, 0.75 mmol), Ph ₂ Se ₂ (19 mg, 0.06 mmol), and DMAP (3.75 mmol) The system was used, and the composition of the catalyst system and activity ^a according to the composition of various catalyst systems are listed in Table 2 below.

Example Catalyst composition Molar ratio
(Se/Ph ₂ Se ₂ /DMAP) BMEC Yield (%) One Se (200 mesh) ^b Ph ₂ Se ₂ - 1/0.08/0 0.4 2 - Ph ₂ Se ₂ DMAP 0/0.08/5 0.9 3 Se (200 mesh) ^b - DMAP 1/0/5 1.0 4 ^SeNPsc - DMAP 1/0/5 53.9 5 Se (200 mesh) ^b Ph ₂ Se ₂ DMAP 1/0.08/5 60.9 6 Se (200 mesh) ^b - - - 0 7 - Ph ₂ Se ₂ - - 0 8 - - DMAP - 0

a) n(MEG/Se/Ph ₂ Se ₂ /DMAP) = 100/1/0.08/5, T = 50 ℃, P = 6.12 MPa (CO/O ₂ = 7/3), t = 1 h done

b) Using Se (200 mesh) bulk particles of 22.2 μm

c) Using selenium nanoparticles (SeNPs) according to Preparation Example 1-2

Examples 9 to 19

Catalytic systems with different compositions were used using MEG (75 mmol), Se (0.75 mmol), Ph ₂ Se ₂ (0.06 mmol), and various bases (B1-B11, 3.75 mmol), and n(MEG/ Relationship between basicity and activity under the conditions Se/Ph ₂ Se ₂ /base) = 100/1/0.08/5, T = 50 ℃, P = 6.12 MPa (CO/O ₂ = 7/3), t = 1 h was analyzed and listed in Table 3 below.

(Example 9)
Pyridine
B1

p K _a = 5.2

Y = 0.6%
TOF = 0.3 h ^-1
(Example 10)
DABCO
B2

p K _a = 8.7

Y = 26.0%
TOF = 13.2 h ^-1
(Example 11)
PPP
B3

p K _a = 8.8

Y = 57.9%
TOF = 31.1 h ^-1
(Example 12)
PPY
B4

p K _a = 9.2

Y = 67.9%
TOF = 35.2 h ^-1
(Example 13)
DMAP
B5

p K _a = 8.9

Y = 60.9%
TOF = 32.5 h ^-1
(Example 14)
Triethylamine
B6

p K _a = 10.7

Y = 3.4%
TOF = 1.7 h ^-1
(Example 15)
TMG
B7

p K _a = 13.0

Y = 0.7%
TOF = 0.4 h ^-1
(Example 16)
DBU
B8

p K _a = 13.5

Y = 4.7%
TOF = 2.3 h ^-1
(Example 17)
KHCO ₃
B9

p K _a = 6.4

Y = 4.8%
TOF = 2.4 h ^-1
(Example 18)
NaOMe
B10

p K _a = 15.5

Y = 3.8%
TOF = 1.9 h ^-1
(Example 19)
KO t -Bu
B11

p K _a = 17.0

Y = 2.1%
TOF = 2.0 h ^-1

* DABCO: 1,4-diazabicyclo[2.2.2]octane; PPP: 4-piperidinopyridine; PPY: 4-pyrrolidinopyridine; DMAP: 4-(dimethylamino)pyridine; TMG: 1,1,3,3-tetramethylguanidine; DBU: 1,8-diazabicyclo[5.4.0]undec-7-ene

Examples 20 to 29

Using MEG (75 mmol), n(Se/Ph ₂ Se ₂ /DMAP) = 1/0.08/5, P = 6.12 MPa (CO/O ₂ = 7/3) for oxidative carbonylation of MEG. The effects of molar ratio, reaction temperature, and time were analyzed and are listed in Table 4 below.

Example Molar ratio
(MEG/Se) Temp.(℃) Time (h) BMEC Yield(%) TOF (h ^-1 ) 20 100 50 One 60.9 32.5 21 200 90 One 57.6 60.1 22 500 90 One 38.5 100.4 23 500 70 One 37.0 96.4 24 500 50 One 15.9 41.1 25 1000 90 One 20.8 103.2 26 1500 90 One 11.5 84.9 27 1000 90 0.25 16.2 332.9 28 1000 90 0.5 16.3 169.7 29 1000 90 0.75 20.5 142.4

Examples 30 to 36

A catalyst system containing ROH (75 mmol), Se (200 mesh, 0.375 mmol), Ph ₂ Se ₂ (0.03 mmol), and DMAP (1.875 mmol) was used, and n(ROH/Se/Ph ₂ Se ₂ /DMAP ) = 200/1/0.08/5, T = 90 ℃, P = 6.12 MPa (CO/O ₂ = 7/3), t = 1 h, oxidative carbonylation reaction and products of MEG according to the type of alcohol The results were analyzed and listed in Table 5 below.

P1


(Example 30)
Dimethyl carbonate
(DMC)

C = 44.8%
S = 97.8%
Y = 43.8%
TOF = 45.2 h ^-1
S _{alkylated Se} ^a = 1.7% ^b P2


(Example 31)
Diethyl carbonate
(DEC)

C = 45.3%
S = 97.6%
Y = 44.2%
TOF = 44.3 h ^-1
S _{alkylated Se} ^a = 1.6% P3


(Example 32)
Dipropyl carbonate
(DPrC)

C = 41.0%
S = 97.8%
Y = 40.1%
TOF = 40.2 h ^-1
S _{alkylated Se} ^a = 1.6% P4


(Example 33)
Dibutyl carbonate
(DBC)

C = 45.2%
S = 99.4%
Y = 44.9%
TOF = 45.0 h ^-1
S _{alkylated Se} ^a = 0.5% P5


(Example 34)
Bis(2,2,2-trifluoroethyl)carbonate
(BTEC)

C = 0%
S = 0%
Y = 0%
TOF = 0 h ^-1
S _{alkylated Se} ^a = 0% P6


(Example 35)
Diphenyl carbonate
(DPC)

C = 0%
S = 0%
Y = 0%
TOF = 0 h ^-1
S _{alkylated Se} ^a = 0% P7


(Example 36)
Bis(2-methoxyethyl)carbonate
(BMEC)

C = 63.2%
S = 95.1%
Y = 57.6%
TOF = 60.1 h ^-1
S _{alkylated Se} ^a = 3.4%

a) S _{alkylated Se} : A by-product of oxidative carbonylation (excluding Ph ₂ Se ₂ ) reaction, its amount or selectivity must be low.

Examples 37 to 39

Using MEG (75 mmol), Se (0.75 mmol), Ph ₂ Se ₂ (0.06 mmol), n(MEG/Se/ Ph ₂ Se ₂ ) = 100/1/0.08, PPY (variable), T = 50 The activity according to the molar ratio of selenium to the pyridine amine compound was analyzed under the conditions of ℃, P = 6.12 MPa (CO/O ₂ = 7/3), and t = 1 h, and is listed in Table 6 below.

Example Catalytic system Molar ratio
(Se/Ph ₂ Se ₂ /DMAP) yield
(%) TOF
(h ^-1 ) 37 Se/Ph ₂ Se ₂ /PPY 1/0.08/1 18.7 9.2 38 Se/Ph ₂ Se ₂ /PPY 1/0.08/3 50.1 24.5 39 Se/Ph ₂ Se ₂ /PPY 1/0.08/5 67.9 35.2

Examples 40 to 43

MEG (75 mmol), Se (0.75 mmol), dialkyl diselenides (R ₂ Se ₂ , 0.06 mmol), PPY (3.75 mmol) were used, and n(MEG/Se/R ₂ Se ₂ / PPY) = 100/1/0.08/5, T = 50 ℃, P = 6.12 MPa (CO/O ₂ = 7/3), t = 1 h, the activity according to the type of accelerator was analyzed and listed in Table 7 below. did.

Example Catalytic system Promoter Yield (%) TOF (h ^-1 ) 40 Se/PPY - 1.1 0.5 41 Se/PPY Ph ₂ Se ₂ 67.9 35.2 42 Se/PPY Me ₂ Se ₂ 54.1 28.0 43 Se/PPY Bz ₂ Se ₂ 54.5 26.6

Examples 44 to 54

MEG (75 mmol), Se (0.75 mmol), n(MEG/Se) = 100, Ph ₂ Se ₂ (variable), PPY (3.75 mmol), n(PPY/Se) = 5, T = 50 The activity according to the molar ratio of the accelerator to selenium was analyzed under the conditions of ℃, P = 6.12 MPa (CO/O ₂ = 7/3), and t = 1 h, and is listed in Table 8 below.

Example Catalyst composition Molar ratio
(Se/Ph ₂ Se ₂ /PPY) Yield
(%) TOF
(h ^-1 ) 44 Se - 45 Se/PPY 1/0/5 1.1 0.5 46 Se/PPY 1/0.0002/5 3.0 1.5 47 Se/PPY 1/0.0004/5 7.5 3.9 48 Se/PPY 1/0.0016/5 22.1 10.9 49 Se/PPY 1/0.008/5 48.2 23.4 50 Se/Ph ₂ Se ₂ /PPY 1/0.04/5 63.3 31.3 51 Se/Ph ₂ Se ₂ /PPY 1/0.08/5 67.9 35.2 52 Se/Ph ₂ Se ₂ /PPY 1/0.16/5 66.8 32.5 53 Se/Ph ₂ Se ₂ /PPY 1/0.32/5 62.7 30.4 54 Se/Ph ₂ Se ₂ /PPY 1/0.64/5 45.5 22.2

Examples 55 to 61

Using ROH (75 mmol), Se (0.375 mmol), Ph ₂ Se ₂ (0.03 mmol), PPY (1.875 mmol), n(ROH/Se/ Ph ₂ Se ₂ /PPY) = 200/1/0.08/ 5, T = 90 ℃, P = 6.12 MPa (CO/O ₂ = 7/3), t = 1 h, the activity according to the type of alcohol was analyzed and listed in Table 9 below.

Example Alcohol (ROH) Catalytic system Yield (%) TOF (h ^-1 ) S- _{alkylated Se}
(%) 55 Methanol Se/PPY 48.8 48.8 1.7 56 Ethanol Se/PPY 49.3 47.8 1.6 57 1-Propanol Se/PPY 44.7 43.4 1.6 58 1-Buthanol Se/PPY 50.1 48.6 0.5 59 2,2,2-Trifluoroethanol Se/PPY 0 0 0 60 Phenol Se/PPY 0 0 0 61 MEG Se/PPY 64.2 64.9 3.4

[Purification of bis(2-methoxyethyl) carbonate (BMEC)]

After the oxidative carbonylation reaction of MEG, selenium powder was removed using a centrifuge. The same volume of water was added to the obtained upper solution to precipitate diphenyldiselenide (Ph ₂ Se ₂ ) and then filtered to obtain a filtrate. To remove water and MEG remaining in the filtrate, it was evaporated under reduced pressure at 90°C using a rotary evaporator. Using silica gel column chromatography using acetone as an eluent, the remaining bis(2-methoxyethyl) carbonate (BMEC) and 4-pyrrolidinopyridine were extracted. (4-pyrrolidinopyridine, PPY) was isolated. Activated carbon (AC) was added to the separated BMEC solution and stirred for one day to remove the color of the solution. Finally, the solution obtained by filtering AC was placed in a rotary evaporator and evaporated under reduced pressure at 60 °C to obtain a clear liquid, which was further dried in a vacuum oven at 60 °C overnight. The clear liquid is pure BMEC. Figure 1 shows a 1H NMR graph of purified BMEC.

[Test example]

Test Example 1: Reaction according to catalyst system configuration

The activity of the catalyst systems according to Examples 1 to 8 was analyzed by reacting as shown in Scheme 3 below.

[Scheme 3]

Referring to Table 2 and Scheme 3 above, when one or more of the components was removed, the yield was very low (Examples 1 to 3). In particular, Example 4 (SeNPs/DMAP) and Example 5 (Se(200 mesh)/Ph ₂ Se ₂ /, which correspond to the use of nano-sized Se or bulk Se with large particle size together with Ph ₂ Se ₂ DMAP) showed very high catalytic activity. Therefore, Se and DMAP are essential parts of the catalyst system, and it is believed that Ph ₂ Se ₂ is likely to play a special role in helping the formation of SeNPs.

Test Example 2: Response according to selenium particle size

The activity of the catalyst system containing selenium particles according to Preparation Examples 1-1, 1-2, 2-1, and 2-2 was analyzed by reacting as shown in Scheme 4 below.

[Scheme 4]

Referring to Table 1 and Scheme 4, the size of SeNPs according to Preparation Example 1-1 was about 60 nm, the yield of BMEC was excellent at 55.9%, and Se prepared without Ph ₂ Se ₂ in Preparation Example 1-2 The size was larger at about 340 nm, but the catalytic activity was almost similar to Preparation Example 1-1. Meanwhile, the size of SeNPs according to Preparation Example 2-1 was about 410 nm, and the BMEC yield was 50.2%, and the size of SeNPs according to Preparation Example 2-2 was about 490 nm, and the BMEC yield was 42.1%. appear.

These results indicate that the size of Se has a significant effect on the activity of Se/DMAP in the oxidative carbonylation of MEG. Although it requires a long pretreatment time (12 h) and a two-step process (Se pretreatment and carbonylation), the formation of SeNPs had significant advantages as an active catalyst for oxidative carbonylation. In addition, as can be seen from Example 5 in Table 2, it was confirmed that adding Ph ₂ Se ₂ to unpretreated Se had a significant effect on BMEC yield and formation of SeNPs, and Ph ₂ Se ₂ was used as a Se/DMAP catalyst. This suggests that addition of oxidative carbonylation irreversibly changes the form of Se to a coarser and smaller particle size.

Test Example 3: Effect of base on the oxidative carbonylation activity of MEG

The relationship between basicity and activity of a catalyst system containing various bases (B1-B11) was analyzed by reacting as shown in Scheme 5 below.

[Scheme 5]

Referring to Table 3 and Scheme 5, DMAP (B5) is known to be a strong base (pKa = 8.9), which showed an excellent promoting effect on the oxidative carbonylation of MEG (see Tables 1 and 2 above). Therefore, more than DMAP (B5), including triethylamine (B6), 1,1,3,3-tetramethylguanidine (TMG; B7), and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU; B8). The reaction was performed assuming that using a strongly basic tertiary amine would provide higher yields of BMEC. However, the super bases TMG and DBU showed extremely low BMEC yields of less than 5%, and KHCO ₃ (B9) as a base showed a BMEC yield of 4.8%. Other strong inorganic bases with pKa values of 15.5 and 17.0, such as NaOMe (B10) and KOt-Bu (B11), also showed very low BMEC yields. This means that basicity is not the only factor that determines the role of the amine. In contrast, relatively low basic amines such as 1,4-diazabicyclo[2.2.2]octane (DABCO; B2, pKa = 8.7) gave a reasonable BMEC yield of 26.0%. Moreover, considering the structural similarity between pyridine (B1) and DMAP (B5), the almost disappearance of the catalytic activity of Se in the presence of low basicity pyridine (pKa = 5.2) suggests that the non-bonding electron pair on the nitrogen atom of pyridine is still utilized. It's interesting because it's possible. In contrast to pyridine, DMAP substantially enhances the activity of Se, producing BMECs in greater than 60% yield. The nitrogen of DMAP is more basic and nucleophilic than pyridine due to the resonance effect of the π-donating NMe ₂ group bound to pyridine. However, bases (TMG and DBU) and nucleophiles (DABCO), which are much stronger than DMAP, were found to be less effective than DMAP, so basicity or nucleophilicity alone cannot explain the superior promoting role of DMAP. A similar trend was also observed for pyridine derivatives with two or more amino groups in the ring structure. For example, 4-piperidinopyridine (PPP, B3) and 4-pyrrolidinopyridine (PPY, B4) with pKa values of 8.8 and 9.2 showed excellent BMEC yields of 57.9 and 67.9%, respectively.

Test Example 4: Activity evaluation according to type of pyridine amine compound

The activities of the catalyst systems according to Examples 1 and 11 to 13 are shown in Table 10 below. MEG (75mmol), Se (0.75mmol), Ph ₂ Se ₂ (0.06mmol), Base (3.75mmol), n(MEG/Se/ Ph ₂ Se ₂ / Base) = 100/1/0.08/5, T = It was evaluated under the conditions of 50°C, P = 6.12 MPa (CO/O ₂ = 7/3), and t = 1h.

Example Catalytic system Base Yield (%) TOF (h ^-1 ) Example 1 Se/Ph ₂ Se ₂ - 0.4 0.2 Example 13 Se/Ph ₂ Se ₂ DMAP 60.9 32.5 Example 11 Se/Ph ₂ Se ₂ PPP 57.9 31.1 Example 12 Se/Ph ₂ Se ₂ PPY 67.9 35.2

According to Table 10, the catalyst system using PPY showed higher yield than the catalyst system using DMAP.

Test Example 5: Catalyst reuse evaluation

Figure 2a shows the results of the reuse evaluation of the Se/Ph ₂ Se ₂ /DMAP catalyst system, and Figures 2b to 2d show the Se recovered from the reaction carried out in the absence of Ph ₂ Se ₂ , DMAP recovered after the first run, and the 5th run. This is a FE-SEM image of DMAP recovered afterward. Additionally, Figures 2e to 2g show 1H NMR spectra of purified Ph ₂ Se ₂ , DMAP, and BMEC.

Catalyst reuse evaluation was performed using MEG (75 mmol), acetone (3 mL, 40.5 mmol), Se (200 mesh, 1.5 mmol), Ph ₂ Se ₂ (0.12 mmol), DMAP (4.5 mmol), n(MEG/Se/Ph ₂ Se Se was recovered by centrifugation after reaction under the conditions of ₂ / DMAP) = 50/1/0.08/3, T = 50°C, P = 6.12 MPa (CO/O ₂ = 7/3), and t = 1h. After washing the Se particles with acetone and drying them at room temperature, the 2nd to 5th recycling experiments were conducted under the same conditions as the 1st without Ph ₂ Se ₂ , and MEG (75 mmol), DMAP (4.5 mmol), and acetone were used. (3 mL) and recovered Se (1.5 mmol) were used. The conversion of MEG and the yield of BMEC were determined using gas chromatography.

Referring to Figure 2A, the recovered system was shown to maintain its original activity (yield over 50% of BMEC) until five consecutive runs. In particular, there was no need to add Ph ₂ Se ₂ in the second run of the recycling experiment. As previously mentioned, this may be because the large, smooth surface of Se (200 mesh) was transformed into smaller, rougher Se particles after Ph ₂ Se ₂ was spiked in the initial addition.

Referring also to Figures _2b -2d, it can be seen that the Se recovered after the initial run contained smaller particles with a rough _surface morphology (ca. 350 nm and It shows that it has a combination of approximately 2.1 μm Se particles, Figure 2c). The size becomes much smaller with a combination of approximately 180 nm and 1.5 μm Se particles in the fifth reaction (Figure 2d).

After each run, all components of the catalyst system were recovered, and the purified 1H NMR data can be seen in Figures 2e to 2g.

Test Example 6: TOF analysis according to molar ratio and reaction time

The maximum TOF for oxidative carbonylation of MEG was analyzed by changing the molar ratio of MEG/Se and reaction time as shown in Scheme 5 below. TOF (Turn Over Frequency) is an indicator that can be used to check how quickly a unit mole of catalyst can produce the target material (desired material). If it can be converted into the desired material in a short period of time, the efficiency of the catalyst can be considered good.

[Scheme 6]

Referring to Table 4 and Scheme 6, a significantly high TOF of 103 h ^-1 was achieved at 90°C under the condition that the MEG/Se molar ratio was 1000 (Example 25). Additionally, when the reaction time was reduced from 1 hour to 45 minutes, 30 minutes, and 15 minutes while maintaining other conditions, a maximum TOF of 333 h ^-1 was achieved at 15 minutes (Example 27).

Test Example 7: Oxidative carbonylation reaction of MEG depending on alcohol type

The oxidative carbonylation reaction of MEG was analyzed according to the type of alcohol by reacting as shown in Scheme 7 below.

[Scheme 7]

Referring to Table 5 and Scheme 7, carbonylation of methanol produced 43.8% DMC with a TOF of 45.2h ^-1 (Example 30). Additionally, ethanol, n-propanol, and n-butanol are highly reactive, with yields of 40–45% for the corresponding DACs (P2-P4), despite the fact that the reactivity of alcohols decreases with increasing alkyl chain length due to steric effects. indicated. However, as observed in the Se/KHCO ₃ system, 2,2,2-trifluoroethanol and phenol (P5 and P6) did not react. Additionally, the selectivities for P1-P4 and P7 were 97.8, 97.6, 97.8, 99.4, and 95.1%, respectively, and by-products such as alkylated Se were negligible. This means that the Se/Ph ₂ Se ₂ /DMAP system follows a highly selective approach towards DAC.

Test Example 8: FT-IR analysis

Figure 3a shows the ATR-FTIR spectra of MEG, activated Se, and DMAP at 50°C, CO/O ₂ (CO/O ₂ = 7/3, 6.12 MPa), and Figure 3b shows the ATR-FTIR spectra at 50°C, CO ( ATR-FTIR spectra (green lines) of MEG, activated Se, and DMAP at 4.28 MPa), 50°C, addition of O ₂ (CO/O ₂ = 7/3, 6.12 MPa), Se (activated Se), This is the ATR-FTIR spectra of DMAP. Figure 3c is also an ATR-FTIR spectra of the solid obtained from the overnight reaction of MEG, activated Se, and DMAP at 50°C under a CO atmosphere (6.12 MPa). Se particles recovered from oxidative carbonylation are referred to as activated Se.

To identify possible intermediates or active species involved in catalysis, ATR-FTIR experiments were performed using activated Se as the main catalyst together with DMAP (excluding Ph ₂ Se ₂ ). The temperature inside the ATR-FTIR reactor was maintained at 50°C, and the IR band was recorded every hour. Spectra of MEG, DMAP and BMEC were recorded with control samples at room temperature.

in situ ATR-FTIR under mixture gas (Figure 3a)

The reaction mechanism was investigated by in situ ATR-FTIR analysis under mixed gas conditions using a Golden Gate reaction cell (Specac) with a ZnSe window. MEG (21 mmol), DMAP (7.5 mmol) and activated Se (obtained after oxidative carbonylation, 1.5 mmol) were added to the reaction cell, then flushed three times and mixed gas (CO/O ₂ = 7/3). The reaction cell was placed in a Nicolet 6700 FTIR spectrometer (Thermo Fisher Scientific, USA) and heated to 50°C, and the FTIR spectrum was recorded at a specific time.

in situ ATR-FTIR under CO followed by adding O ₂ (Figure 3b)

In situ ATR-FTIR analysis was performed in a CO atmosphere, and then O ₂ was added to a Golden Gate reaction cell with a diamond window to determine the origin of the peak at 1644 cm ^-1 . The experimental details were the same as above, except for using CO as the flushing and pressurizing gas until a certain pressure was reached. After 3 hours, O ₂ gas was added to the reactor at 50° C. until the pressure reached 6.12 MPa. Measurements were monitored in real time, and FTIR spectra were recorded at specific times.

ex situ ATR-FTIR (Figure 3c)

Se carbonyl complexes were analyzed by ex situ ATR-FTIR using a Nicolet iS10 FTIR spectrometer (Thermo Fisher Scientific, USA) equipped with a SMART MIRacle accessory (ZnSe window). Before measurement, activated Se (obtained after oxidative carbonylation, 5 mmol) was collected after treatment with DMAP (10 mmol) and MEG (65 mmol) in a pressurized reactor in a CO atmosphere (6.12 MPa) at 50°C overnight. After completion of CO treatment, wet solids (including MEG) were collected and immediately subjected to ATR-FTIR analysis.

Referring to Figures 3a to 3c, the stretching frequency ν(C=C) of aromatics in DMAP shifted to higher values from 1595, 1537, and 1514 to 1606, 1541, and 1527 cm ^-1 , respectively, in the presence of MEG at room temperature ( Figure 3a, red line). At the same time, the frequency of hydroxyl groups in MEG shifted to a lower value from 3424 to 3405 cm ^-1 , indicating the extension of OH bonds (Figure 3a). These results mean that the hydrogen bond between ROH (MEG) and DMAP, which is responsible for the appearance of the peaks at 1606, 1541, and 1527 cm ^-1 , was formed by simply mixing these substances (Scheme 1). Here, the nitrogen of the pyridine ring acts as an H-bond acceptor, and H-OR acts as an H-bond donor. Therefore, it is believed that DMAP acts as an H-bond acceptor in the presence of alcohol, making the lone pair of oxygen atoms in the OR portion more nucleophilic in the catalytic system.

[Scheme 1]

Additionally, when the temperature reached 50°C, the free CO peak disappeared and a new peak was observed at 1751 cm ^-1 (Figure 3a, light blue line). The intensity of this peak at 1751 cm ^-1 increased with time, which is attributed to the carbonyl group of BMEC (Figure 3a, blue line). The intensities at 2337 and 1644 cm ^-1 also increased simultaneously (Figure 3a), and these peaks were attributed to by-products CO ₂ and H ₂ O, respectively.

Additionally, the green line in Figure 3b represents the in situ time-dependent ATR-FTIR spectra of MEG, DMAP, and activated Se in CO (4.28 MPa) at 50°C. The peak at 1644 cm ^-1 was still observed even without O ₂ , and another peak was generated at 1562 cm ^-1 after 3 hours. After introducing O ₂ (1.84 MPa) into the ATR-FTIR reaction cell (blue line in Figure 3b), the carbonyl peak of BMEC was observed along with free CO ₂ (2337 cm ^-1 ), indicating that the catalytic system is capable of producing O ₂ This means that it started working again after introduction. However, the intensity of the peaks at 1644 and 1562 cm ^-1 did not increase any further.

Also, in Figure 3c, the peaks at 1644 and 1562 cm ^-1 are MEG... It reappeared along with the original peak of DMAP. Immediately after exposure to air, this peak shifted to 1637 and 1556 cm ^-1 and then completely disappeared after exposure to air for 1 hour. These results suggest that the peak at 1644 cm ^-1 does not occur only in H ₂ O but is due to the production of a specific species that is formed instantaneously together with the species at 1562 cm ^-1 . This peak may be responsible for an important intermediate in the Se/DMAP-catalyzed oxidative carbonylation of MEG.

Test Example 9: DFT analysis

Figure 4a is a relative energy diagram for the Se/DMAP catalyzed reaction to identify the key role of DMAP, shown in black and blue, with comparative energy levels shown in yellow when DMAP is not present and when DMAP acts as an H-bond acceptor. It is displayed in red when it only works. Additionally, the value of activation energy is displayed in a round inset box. Additionally, Figure 4b shows the oxidative carbonylation reaction mechanism of alcohol to produce DAC, with intermediates indicated in Roman letters. To understand the outstanding performance of DMAP and propose a reliable reaction mechanism, the energy profile for the carbonylation of MEG to DAC was analyzed through density functional theory (DFT) calculations.

Referring to Figure 4a, the exploration began with SeCO(II) because DMAP as a base has been reported to promote the carbonylation of elemental selenium Se(I) to form SeCO(II). The first step is H-bonded MEG… This is SeCO's approach to DMAP. This is SeCO and MEG… It is an exothermic process due to the interaction between DMAP (-47.6 kJ mol ^-1 , II', black line in Figure 4a). In the absence of DMAP, this interaction is much weaker (-9.9 kJ mol ^-1 , ii', yellow line in Fig. 4a), suggesting that the presence of DMAP inhibits MEG… It indicates that it strengthens the interaction between DMAP and SeCO. This interaction energy trend can be explained by the higher value of the oxygen charge in the hydroxyl group of MEG (-1.832 e ^{- )} with DMAP arising from H-bonds compared to free MEG (-1.750 e - ). Formation of intermediate III occurs through the enhanced nucleophilicity of the oxygen atom of MEG onto the carbonyl group of SeCO… It occurs through nucleophilic addition of DMAP. The energy barrier for this reaction is much lower with DMAP (34.5 kJ mol ^-1 , II' to TSII') than without DMAP (127.0 kJ mol ^-1 , ii' to TSii'-iii, yellow line in Figure 4a). -III, black line in Figure 4a). The DMAP-free transition state (TS) structure, TSii'-iii, shows a large distortion of the selenocarbonate structure (Se(SeCO)-C(SeCO)-O(MEG): 99˚), resulting in a high energy barrier. In the presence of DMAP, much less distortion of the selenocarbonate structure was observed in the TSII'-III structure (Se(SeCO)-C(SeCO)-O(MEG): 110˚). Here, DMAP acts as a proton shuttle and helps transfer DMAP‥HOR to DMAP‥HSe(C=O)OR(III), resulting in a low energy barrier of TSII'-III. The above results also show the importance of DMAP as an H-bond receptor.

In addition, the calculated ν(C=O) frequency of the carbonyl stretching frequency of intermediate III (DMAP...O-alkyl Se-hydrogen selenocarbonate complex, DMAP...HSe(C=O)OR) is 1704 cm ^-1 , which is in this region. The structure of species III is almost identical to that of Sonoda's selenocarbonate, although the carbonyl peak was not observed in the ATR-FTIR study. Therefore, species III can exist in this catalytic cycle without difficulty. III reacts with additional DMAP to form IV. There are two plausible pathways depending on the role of DMAP. The first is DMAP(TSIII-IV) as a nucleophile (Figure 4) and the other is DMAP(TSIII-iv) as an H-bond acceptor. For H-coupled receptors, the activation barrier is higher than for nucleophiles, so the route through TSIII-iv is eliminated. When DMAP acts as a nucleophile, it approaches the carbonyl carbon of III. The C(III)-N(DMAP) bond of TSIII-IV is closer (1.90 Å), while the C(III)-Se(III) bond is longer (2.07 Å), which makes the carbonyl carbon of III the parent of DMAP. DMAP as a nucleophilic substitution and leaving group… This indicates the departure of the H-Se portion. The leaving group is stabilized by intermolecular ionic interactions between the DMAP-ester moieties, resulting in a low energy barrier (73.0 kJ mol ^-1 ). Here DMAP… The H-Se part has a negative charge and the DMAP-ester part has a positive charge. Additionally, the mechanism via intermediate IV is similar to the esterification mechanism in which DMAP acts as a nucleophile. Lastly, MEG… DMAP attacks the carbonyl carbon of IV through TSIV-V with a low energy barrier of 37.8 kJ mol ^-1 and then generates V and DAC. As V interacts with 1/2 O _{2 ,} Se(I) and DMAP are regenerated, and based on in situ ATR-FTIR and DFT studies, the reaction mechanism of Se/DMAP-catalyzed oxidative carbonylation of alcohols is shown in Figure 4b. It is described in .

Test Example 10: Activity analysis according to molar ratio of selenium to pyridine amine compound

Referring to Table 6, when the molar ratio of pyridine amine compound (PA) to selenium (Se) (PA/Se) was 5, the yield was highest.

Test Example 11: Activity analysis according to type of accelerator

Figure 5 is a FE-SEM image of selenium recovered in reactions performed with catalyst systems according to various promoters. (a) is Se/Ph ₂ Se ₂ /PPY = 1/0.08/5 (Example 41), (b) is Se/Me ₂ Se ₂ /PPY = 1/0.08/5 (Example 42), (c) ) Se/Bz ₂ Se ₂ /PPY = 1/0.08/5 (Example 43).

Referring to Table 7 and Figure 5, when the accelerator was Ph ₂ Se ₂ , the yield was highest.

Test Example 12: Activity analysis according to molar ratio of accelerator to selenium

Referring to Table 8, the yield was highest when the molar ratio (Ph ₂ Se ₂ /Se) of the accelerator (Ph ₂ Se ₂ ) to selenium (Se) was 0.08.

Test Example 13: Activity analysis according to alcohol type

Referring to Table 9 above, it was confirmed that the reactivity of the catalyst did not decrease even if the carbon number of the alcohol increased to C4, and the yield was about 45% or more and the selectivity of alkylated selenium, a by-product, was within about 2%. did. Additionally, no reaction was observed between phenol and 2,2,2-trifluoroethanol, which has an electron-withdrawing functional group.

Although the preferred embodiments of the present invention have been described above, those skilled in the art will be able to add, change, delete or modify components without departing from the spirit of the present invention as set forth in the patent claims. The present invention may be modified and changed in various ways by addition, etc., and this will also be included within the scope of rights of the present invention. For example, each component described as unitary may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form. The scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

Claims (20)

Selenium (Se); and
A pyridine amine compound represented by the structural formula 1 below;
A catalyst system for producing carbonate derivatives comprising:
[Structural Formula 1]

In structural formula 1,
n is an integer from 1 to 4. According to paragraph 1,
A catalyst system for producing a carbonate derivative, wherein the pyridine amine compound is any one selected from the group consisting of 4-piperidinopyridine (PPP) and 4-pyrrolidinopyridine (PPY). According to paragraph 1,
The catalyst system is a catalyst system for producing a carbonate derivative, characterized in that the molar ratio (PA/Se) of the pyridine amine compound (PA) to the selenium (Se) is 1 to 6. According to paragraph 1,
A catalyst system for producing a carbonate derivative, characterized in that the catalyst system further includes a promoter. According to paragraph 4,
A catalyst system for producing carbonate derivatives, wherein the accelerator is for producing selenium nanoparticles. According to paragraph 4,
The accelerator is a group consisting of diphenyl diselenide (Ph ₂ Se ₂ ), dimethyl diselenide (Me ₂ Se ₂ ), dibenzyl diselenide (Bz ₂ Se ₂ ) and diphenyl selenide (Ph ₂ Se). A catalyst system for producing a carbonate derivative, comprising at least one selected from the group consisting of According to paragraph 4,
A catalyst system for producing carbonate derivatives, wherein the accelerator includes diphenyldiselenide (Ph ₂ Se ₂ ). According to paragraph 4,
The catalyst system is a catalyst system for producing carbonate derivatives, characterized in that the molar ratio of the promoter to selenium (Se) (promoter/Se) is 0.00016 to 0.64. According to paragraph 1,
A catalyst system for producing a carbonate derivative, characterized in that the carbonate derivative is a compound represented by structural formula 2 below:
[Structural Formula 2]

In structural formula 2,
R ³ is each independently a C1 to C6 alkylene group,
R ⁴ is each independently a hydrogen atom or ego,
R ⁵ is each independently a C1 to C3 alkyl group. According to clause 9,
A catalyst system for producing a carbonate derivative, characterized in that the carbonate derivative is bis(2-methoxyethyl) carbonate (BMEC). According to paragraph 1,
A catalyst system for producing a carbonate derivative, characterized in that the selenium has a nanoparticle or bulk shape. According to clause 11,
A catalyst system for producing carbonate derivatives, characterized in that the nanoparticle shape has a size of 10 to 1,000 nm. In paragraph 11
A catalyst system for producing carbonate derivatives, characterized in that the bulk shape is greater than 1 μm and less than 50 μm. In Scheme 1, a method for producing a carbonate derivative comprising the step of preparing Compound 2 by reacting reactants containing Compound 3, carbon monoxide, and oxygen using a catalyst system as shown in Scheme 1:
[Scheme 1]

In Scheme 1 above,
R ³ is each independently a C1 to C6 alkylene group,
R ⁴ is each independently a hydrogen atom or ego,
R ⁵ is each independently a C1 to C3 alkyl group. According to clause 14,
The catalyst system includes selenium (Se); A method for producing a carbonate derivative, characterized in that it is a catalyst system comprising a pyridine amine compound represented by the following structural formula 1.
[Structural Formula 1]

In structural formula 1,
n is an integer from 1 to 4. According to clause 15,
A method for producing a carbonate derivative, characterized in that the pyridine amine compound is any one selected from the group consisting of 4-piperidinopyridine (PPP) and 4-pyrrolidinopyridine (PPY). According to clause 15,
A method for producing a carbonate derivative, wherein the catalyst system further includes a promoter. According to clause 17,
The accelerator is a group consisting of diphenyl diselenide (Ph ₂ Se ₂ ), dimethyl diselenide (Me ₂ Se ₂ ), dibenzyl diselenide (Bz ₂ Se ₂ ) and diphenyl selenide (Ph ₂ Se). A method for producing a carbonate derivative, comprising at least one selected from the group consisting of According to clause 17,
A method for producing a carbonate derivative, characterized in that the accelerator includes diphenyl diselenide (Ph ₂ Se ₂ ). According to clause 14,
A method for producing a carbonate derivative, characterized in that the reaction is carried out at 10 to 150 ° C.