CN109851507B - Application of scandium-containing rare earth catalyst in catalysis of para-alkylation reaction of aromatic amine - Google Patents

Abstract

芳香胺为芳香一级胺或芳香二级胺。本发明还公开了一种对位烷基化的芳香胺的制备方法：将式(1)的芳香胺和式(2)的烯烃在含钪稀土催化剂的催化作用下，在有机溶剂中于60‑150℃下反应，得到所述对位烷基化的芳香胺，反应路线如下：

其中，R¹为氢、芳香基或C₁‑C₁₀烷基；R²为氢、C₁‑C₄烷基、C₁‑C₄烷氧基、芳基或卤素；且R²不能取代在对位；X为亚甲基或硫原子，n1为0‑4中的任一数值；R³为C₁‑C₂₀烷基、芳基或与R⁵通过若干亚甲基成环，亚甲基的个数n2为1‑4中的任一数值；R⁴为氢、C₁‑C₂₀烷基、芳基、噻吩基、苯并呋喃基或取代芳基；R⁵为氢、甲基或亚甲基；R⁶为氢。The invention relates to the application of a scandium-containing rare earth catalyst in catalyzing the para-selective alkylation reaction of aromatic amines. The structural formula of the scandium-containing rare earth catalyst is as follows:

Aromatic amines are aromatic primary amines or aromatic secondary amines. The invention also discloses a preparation method of a para-alkylated aromatic amine: the aromatic amine of the formula (1) and the olefin of the formula (2) are catalyzed by a scandium-containing rare earth catalyst in an organic solvent at 60 -150 ℃ of reaction, obtain the aromatic amine of described para-alkylation, reaction scheme is as follows:

Wherein, R ¹ is hydrogen, aryl or C ₁ -C ₁₀ alkyl; R ² is hydrogen, C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, aryl or halogen; and R ² cannot be substituted In the para position; X is a methylene group or a sulfur atom, n1 is any value in 0-4; R ³ is a C ₁ -C ₂₀ alkyl group, an aryl group or a ring with R ⁵ through several methylene groups, and The number n2 of methyl groups is any value in 1-4; R ⁴ is hydrogen, C ₁ -C ₂₀ alkyl, aryl, thienyl, benzofuranyl or substituted aryl; R ⁵ is hydrogen, methyl group or methylene; R ⁶ is hydrogen.

Description

Application of rare earth catalysts containing scandium in catalytic para-alkylation of aromatic amines

technical field

The invention relates to the field of organic synthesis, in particular to the application of a scandium-containing rare earth catalyst in catalyzing the para-alkylation reaction of aromatic amines.

Background technique

Aromatic amines and their derivatives are widely used in drugs, fluorescent dyes, natural products and organic functional materials. However, most aromatic amines are currently prepared through multi-step functional group transformations. Such compounds can be synthesized simply and efficiently if the direct addition of simple aromatic amines to unsaturated olefins can be realized. However, the traditional Friedel-Crafts alkylation usually uses a stoichiometric or catalytic amount of Lewis acid as a catalyst, so it is easy to form an acid-base adduct when reacting with a more basic aromatic amine substrate, which makes the reaction unable to proceed.

Although the use of different types of transition metal (ruthenium, rhodium, iridium, zinc, gold, yttrium and titanium) catalysts or the use of Bronsted acids and ionic liquids as catalysts has been used for the alkylation of aromatic amines and olefins, the reaction The chemical selectivity and regioselectivity are very poor. Usually, hydroamination products and ortho-alkylated products of aromatic amines are obtained, and only a very small amount of para-alkylated products of aromatic amines can be obtained. And only the para-specific alkylation of tertiary aromatic amines and α, β-unsaturated aldehydes and ketones similar to active alkene substrates can be realized. Existing synthesis methods have not yet realized the para-specific alkylation of aromatic primary amines and secondary amines with multiple types of inactive olefins simultaneously with one catalyst. In addition, the amount of catalyst used in the above method is relatively large, usually more than 20%.

Patent CN201710441715 discloses rare earth metal complexes based on diimine ligands and applications thereof, and uses scandium-containing catalysts to catalyze the reaction of olefins and aromatic amines, but the method in this patent cannot achieve the para-alkylation of aromatic amines.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned technical problems, the purpose of the present invention is to provide the application of a scandium-containing rare earth catalyst in catalyzing the para-alkylation reaction of aromatic amines. The invention discloses a new application of the scandium-containing rare earth catalyst, which can catalyze aromatic amine and The para-selective alkylation of a variety of alkenes, the method has a wide range of substrates, functional group tolerance and high regioselectivity.

The first object of the present invention is to disclose the application of a scandium-containing rare earth catalyst in catalyzing the para-selective alkylation of aromatic amines, wherein the structural formula of the scandium-containing rare earth catalyst is as follows:

所述芳香胺为芳香一级胺或芳香二级胺。

The aromatic amine is an aromatic primary amine or an aromatic secondary amine.

Further, the reaction is an addition reaction of aromatic amine and olefin, and the reaction temperature is 60-150°C.

Further, the structural formula of aromatic amine is shown in formula (1), and the structural formula of alkene is shown in formula (2):

其中，

in,

R ¹ is hydrogen, aryl or C ₁ -C ₁₀ alkyl;

R ² is hydrogen, C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, aryl or halogen; and R ² cannot be substituted at the para position;

X is a methylene group or a sulfur atom, and n1 is any value from 0 to 4;

R ³ is a C ₁ -C ₂₀ alkyl group, an aryl group, or forms a ring with R ⁵ through several methylene groups, and the number n2 of methylene groups is any value from 1 to 4;

R ⁴ is hydrogen, C ₁ -C ₂₀ alkyl, aryl, thienyl, benzofuranyl or substituted aryl;

R ⁵ is hydrogen, methyl or methylene;

R ⁶ is hydrogen.

Further, the amount of scandium-containing rare earth catalyst used is 1-20 mol% of the olefin.

The second object of the present invention is to provide a preparation method of a para-alkylated aromatic amine, comprising the following steps:

The aromatic amine of the formula (1) and the olefin of the formula (2) are reacted in an organic solvent at 60-150° C. under the catalysis of a scandium-containing rare earth catalyst and a co-catalyst to obtain the para-alkylated aromatic Amine, wherein, the structural formula of the scandium-containing rare earth catalyst is as follows:

所述共催化剂中含有B(C₆F₅)₃基；

The co-catalyst contains B(C ₆ F ₅ ) ₃ groups;

The reaction route is as follows:

其中，

in,

R ¹ is hydrogen, aryl or C ₁ -C ₁₀ alkyl;

R ² is hydrogen, C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, aryl or halogen; and R ² cannot be substituted at the para position;

X is a methylene group or a sulfur atom, and n1 is any value from 0 to 4;

R ³ is a C ₁ -C ₂₀ alkyl group, an aryl group, or forms a ring with R ⁵ through several methylene groups, and the number n2 of methylene groups is any value from 1 to 4;

R ⁴ is hydrogen, C ₁ -C ₂₀ alkyl, aryl, thienyl, benzofuranyl or substituted aryl;

R ⁵ is hydrogen, methyl or methylene;

R ⁶ is hydrogen.

Further, in the present invention, the aryl group is preferably a phenyl group.

Further, in the present invention, the substituents in the substituted aryl group are preferably C ₁ -C ₁₀ alkoxy and halogen.

Further, in the present invention, the halogen is F, Cl, Br or I.

Further, the co-catalyst is [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ], [Ph ₃ C][B(C ₆ F ₅ ) ₄ ] or B(C ₆ F ₅ ) ₃ .

Further, the amount of the co-catalyst is 1-20 mol% of the total reactants. Preferably, the amount of co-catalyst is 10-15 mol % of the total reactants; more preferably, the amount of co-catalyst is 10 mol % of the total reactants.

Further, the amount of scandium-containing rare earth catalyst used is 1-20 mol% of the olefin. Preferably, the amount of the scandium-containing rare earth catalyst is 10-15 mol% of the olefin; more preferably, the amount of the scandium-containing rare earth catalyst is 10 mol% of the olefin.

Preferably, the reaction temperature is 100-120°C; more preferably, the reaction temperature is 120°C.

Preferably, the aromatic amine is N-methylaniline, 2-bromo-N-methylaniline, 2-methyl-N-methylaniline, 2-fluoro-N-methylaniline, indoline, N-ethylaniline aniline, 3,4-dihydro-2H-1,4-benzothiazine, diphenylamine, aniline, o-methoxyaniline, o-chloroaniline or phenylhydrazine.

Preferably, the olefin is α-methylstyrene, 4-methoxy-α-methylstyrene, 4-chloro-α-methylstyrene, 3-bromo-α-methylstyrene, α-propylene styrene, 1,1-stilbenestyrene, 2-isopropenylthiophene, 2-(α-methylvinyl)benzofuran, 2-phenylbut-2-ene or 1-phenyl ring hexene.

Further, the scandium-containing rare earth catalyst and the co-catalyst are first reacted at 20-30°C, and after the reaction is complete, the aromatic amine of formula (1) and the olefin of formula (2) are added to react at 60-150°C.

Further, the molar ratio of the aromatic amine of formula (1) and the olefin of formula (2) is 1.5:1.0.

Further, the organic solvent is one or more of toluene, chlorobenzene, bromobenzene and tetrahydrofuran.

Taking the reactants as N-methylaniline and α-methylstyrene as examples, the reaction principle of the present invention is as follows: in the reaction process, a cationic scandium active species is first generated, and the compound catalyzes the intermolecular hydrogenamination reaction and then further. A rearrangement reaction occurs selectively to produce para-alkylated products.

By means of the above scheme, the present invention has at least the following advantages:

The invention discloses a new application of scandium-containing rare earth catalyst, breaks through the limitation that the traditional Friedel-Crafts alkylation reaction cannot realize the hydroalkylation reaction of aromatic amine and olefin, and improves the C-H functionalization of aromatic amine catalyzed by the transition metal catalyst. regioselectivity and chemoselectivity. For the first time, the para-specific alkylation of aromatic primary or secondary amines with a variety of olefins was achieved simultaneously with rare earth catalysts, and it has a wide range of substrates, high functional group tolerance and regioselectivity.

The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly and implement it according to the content of the description, the preferred embodiments of the present invention are described in detail below.

Detailed ways

The specific embodiments of the present invention will be further described in detail below with reference to the examples. The following examples are intended to illustrate the present invention, but not to limit the scope of the present invention.

In the following examples, the structural formula of the scandium-containing rare earth catalyst used is as follows:

将其简称为L1。

It is abbreviated to L1.

"toluene" in the reaction equation represents toluene. "10 mol%" means that it is 10% of the total moles of olefin.

Example 1

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. The reaction was completed, N-methylaniline (48 mg) and α-methylstyrene (35 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a pale yellow oily liquid (61 mg, yield 91%).

HRMS (ESI) m/z calculated: C ₁₆ H ₁₉ NNa ⁺ [M+Na] ⁺ : 248.1410; found: 248.1400.

¹ H NMR (400MHz, CDCl ₃ , 298K) δ=7.18 (m, 4H, o-Ph, m-Ph), 7.08 (m, 1H, p-Ph), 6.99 (m, 2H, m-PhN), 6.47 (m, 2H, o-PhN), 3.40 (brs, 1H, NH), 2.74 (s, 3H, _NCH3 ), 1.57 (s, 6H, _CMe2 ).

¹³ C{ ¹ H} NMR (101MHz, CDCl ₃ , 298K) δ=151.5(i-Ph), 147.1(i-PhN), 139.8(p-PhN), 128.0(m-Ph), 127.7(m-PhN) ), 126.9 (o-Ph), 125.5 (p-Ph), 112.3 (o-PhN), 42.3 (CMe ₂ ), 31.1 (NHCH ₃ ), 31.0 (CMe ₂ ).

Example 2

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 15 minutes. The reaction was completed, N-methylaniline (48 mg) and 4-methoxy-α-methylstyrene (44 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a pale yellow oily liquid (70 mg, yield 92%).

HRMS (ESI) m/z calculated: _C17H21NNaO [M+Na] ⁺ : _278.1515 ; found: 278.1526.

¹ HNMR (400MHz, CDCl ₃ , 298K) δ=7.18 (m, 2H, o-Ph), 7.08 (m, 2H, m-PhN), 6.82 (m, 2H, m-Ph), 6.56 (m, 2H , o-PhN), 3.80 (m, 4H, OMe, NHCH ₃ ), 2.83 (s, 3H, NHCH ₃ ), 1.64 (s, 6H, CMe ₂ ).

¹³ CNMR (101MHz, CDCl ₃ , 298K) δ=157.3(p-Ph), 147.1(i-PhN), 143.7(i-Ph), 140.0(p-PhN), 127.8(o-Ph), 127.6(m -Ph), 113.3 (m-PhN), 112.2 (o-PhN), 55.3 (OMe), 41.6 (CMe ₂ ), 31.2 (CMe ₂ ), 31.0 (NHCH ₃ ).

Example 3

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. The reaction was completed, N-methylaniline (48 mg) and 4-chloro-α-methylstyrene (46 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a pale yellow oily liquid (64 mg, yield 89%).

HRMS (ESI) m/z calculated: C16H19ClN[M+H] ⁺ : _260.1201 ; found: _260.1205 .

¹ H NMR (400MHz, CDCl ₃ , 298K) δ=7.17 (m, 4H, o-Ph, m-Ph), 7.02 (m, 2H, m-PhN), 6.51 (m, 2H, o-PhN), 3.57 (brs, 1H, _NHCH3 ), 2.79 (s, 3H, _NHCH3 ), 1.61 (s, 6H, _CMe2 ).

¹³ C NMR (101MHz, CDCl ₃ , 298K) δ=150.1(i-Ph), 147.3(i-PhN), 138.9(p-PhN), 131.2(p-Ph), 128.3(o-Ph), 128.0( m-PhN), 127.5 (m-Ph), 112.2 (o-PhN), 42.0 (CMe ₂ ), 31.0 (CMe ₂ ), 30.9 (NHCH ₃ ).

Example 4

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. The reaction was completed, N-methylaniline (48 mg) and 3-bromo-α-methylstyrene (59 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a pale yellow oily liquid (77 mg, yield 85%).

HRMS (ESI) m/z calcd: _C16H19BrN [M+H] ⁺ : _304.0695 ; found: 304.0709.

¹ H NMR (400MHz, CDCl ₃ , 298K) δ=7.40 (m, 1H, 2-Ph), 7.27 (m, 1H, 4-Ph), 7.11 (m, 2H, 5-Ph), 7.02 (m, 2H, m-PhN), 6.52 (m, 2H, o-PhN), 3.58 (brs, 1H, _NHCH3 ), 2.79 (s, 3H, _NHCH3 ), 1.61 (s, 6H, _CMe2 ).

¹³ C NMR (101MHz, CDCl ₃ , 298K) δ=154.0(1-Ph), 147.4(i-PhN), 138.6(p-PhN), 129.9(2-Ph), 129.6(5-Ph), 128.6( 4-Ph), 127.6(m-PhN), 125.8(6-Ph), 122.3(3-Ph), 112.2(o-PhN), 42.3(CMe ₂ ), 30.9(CMe ₂ ), 30.8(NHCH ₃ ) .

Example 5

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. After the reaction was completed, N-methylaniline (48 mg) and α-propylstyrene (44 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a pale yellow oily liquid (66 mg, yield 87%).

HRMS (ESI) m/z calculated: _C18H24N [ _M +H] ⁺ : 254.1903; found: 254.1916.

¹ H NMR (400MHz, CDCl ₃ , 298K): δ = 7.22 (m, 4H, o-Ph, m-Ph), 7.13 (m, 1H, p-Ph), 7.00 (m, 2H, m-PhN) , 6.52 (m, 2H, o-PhN), 3.57 (brs, 1H, NHCH ₃ ), 2.80 (s, 3H, NHCH ₃ ), 2.01 (t, ³ J _HH = 8.3Hz, 2H, CCH ₂ ), 1.58 (s, 3H, CCH ₃ ), 1.11 (m, 2H, CH ₂ CH ₃ ), 0.87 (t, ³ J _HH = 7.3 Hz, 3H, CH ₂ CH ₃ ).

¹³ C{ ¹ H} NMR (101 MHz, CDCl ₃ , 298K): δ=150.7 (i-Ph), 147.1 (i-PhN), 138.8 (p-PhN), 128.2 (m-PhN), 127.9 (m- Ph), 127.4(o-Ph), 125.4(p-Ph), 112.1(o-PhN), 45.6(CCH ₃ ), 44.5(CCH ₂ ), 31.0(NHCH ₃ ), 27.9(CCH ₃ ), 18.2( CH ₂ CH ₃ ), 15.0 (CH ₂ CH ₃ ).

Example 6

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. After the reaction was completed, N-methylaniline (48 mg) and 1,1-stilbene styrene (54 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a pale yellow oily liquid (70 mg, yield 81%).

HRMS (ESI) m/z calculated: _C21H22N [M+H] ⁺ : _288.1747 ; found: 288.1756.

¹ H NMR (400 MHz, CDCl ₃ , 298K): δ=7.21 (m, 4H, m-Ph), 7.15 (m, 2H, p-Ph), 7.10 (m, 4H, o-Ph), 6.89 (m , 2H, m-PhN), 6.46 (m, 2H, o-PhN), 3.53 (brs, 1H, NHCH ₃ ), 2.73 (s, 3H, NHCH ₃ ), 2.12 (s, 3H, CCH ₃ ).

¹³ C{ ¹ H} NMR (101 MHz, CDCl ₃ , 298K): δ=149.8(i-Ph), 147.3(i-PhN), 137.7(p-PhN), 129.5(m-PhN), 128.8(o- Ph), 127.8 (m-Ph), 125.8 (p-Ph), 111.8 (o-PhN), 51.8 (CCH ₃ ), 30.8 (NHCH ₃ ), 30.6 (CCH ₃ ).

Example 7

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. The reaction was completed, N-methylaniline (48 mg) and 2-isopropenylthiophene (37 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a pale yellow oily liquid (67 mg, yield 88%).

HRMS (ESI) m/z calcd: _C14H17NNaS [M+H] ⁺ : _254.0974 ; found: 254.0973.

¹ H NMR (400 MHz, CDCl ₃ , 298K) δ 7.16 (m, 3H, m-Ph, 2-C ₄ H ₃ ), 6.92 (m, 1H, 3-C ₄ H ₃ ), 6.83 (m, 1H , ₄ - _C4H3 ), 6.57 (m, 2H, o-PhN), 3.65 (brs, 1H, _NHCH3 ), 2.84 (s, 3H, _NHCH3 ), 1.77 (s, 6H, _CMe2 ).

¹³ C NMR (101 MHz, CDCl ₃ , 298K) δ=157.6 (1-C ₄ H ₃ ), 147.6 (i-PhN), 138.7 (p-PhN), 127.1 (m-PhN), 126.2 (3-C ₄ ) H3), 123.3 ( ₄ - _C4H3 ), 123.0 ( _{2 - C4H3} ), 112.1 (o-PhN), 40.9 ( _CMe2 ), 32.3 ( _CMe2 ), 30.9 ( _NHCH3 ).

Example 8

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. The reaction was completed, N-methylaniline (48 mg) and 2-(α-methylvinyl)benzofuran (47 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a pale yellow oily liquid (74 mg, yield 93%).

HRMS (ESI) m/z calculated: _C18H19NNaO [M+Na] ⁺ : _288.1359 ; found: 288.1357.

¹ H NMR (400 MHz, CDCl ₃ , 298K) δ = 7.39 (m, 1H, 4-C ₈ H ₆ ), 7.28 (m, 1H, 6-C ₈ H ₆ ), 7.07 (m, 4H, 2-C ₈ H ₆ , 5-C ₈ H ₆ , m-PhN), 6.43 (m, 2H, o-PhN), 6.35 (m, 1H, 7-C ₈ H ₆ ), 3.48 (brs, 1H, NHCH ₃ ) , 2.68 (s, 3H, NHCH ₃ ), 1.63 (s, 6H, CMe ₂ ).

¹³ C NMR (101 MHz, CDCl ₃ , 298K) δ = 166.4 (1-C ₈ H ₆ ), 154.9 (8-C ₈ H ₆ ), 147.8 (i-PhN), 135.7 (p-PhN), 128.8 (3 -C ₈ H ₆ ), 127.0 (m-PhN), 123.3 (2-C ₈ H ₆ ), 122.4 (5-C ₈ H ₆ ), 120.5 (4-C ₈ H ₆ ), 112.3 (o-PhN) , 111.2 (6-C ₈ H ₆ ), 101.3 (7-C ₈ H ₆ ), 39.9 (CMe ₂ ), 30.9 (NHCH ₃ ), 28.6CMe ₂ ).

Example 9

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. The reaction was completed, N-methylaniline (48 mg) and 2-phenylbut-2-ene (40 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a pale yellow oily liquid (56 mg, yield 78%).

HRMS (ESI) m/z calculated: _C17H22N [M+H] ⁺ : _240.1747 ; found: 240.1758.

¹ H NMR (400MHz, CDCl ₃ , 298K) δ=7.20 (m, 4H, o-Ph, m-Ph), 7.11 (m, 1H, p-Ph), 7.00 (m, 2H, m-PhN), 6.49 (m, 2H, o-PhN), 3.56 (brs, 1H, NHCH ₃ ), 2.75 (s, 3H, NHCH ₃ ), 2.08 (q, ³ J _HH = 7.4Hz, 2H, CCH ₂ CH ₃ ), 1.55 (s, 3H, CMe), 0.72 (t, ³ J _HH = 7.3 Hz, 3H, CCH ₂ CH ₃ ).

¹³ C NMR (101 MHz, CDCl ₃ , 298K) δ=150.4(i-Ph), 147.0(i-PhN), 138.4(p-PhN), 128.2(m-PhN), 127.8(m-Ph), 127.5( o-Ph), 125.3 (p-Ph), 112.0 (o-PhN), 45.7 (CMe), 34.2 (CCH ₂ CH ₃ ), 30.9 (NHCH ₃ ), 27.1 (CMe), 9.3 (CCH ₂ CH _{3 )} .

Example 10

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. The reaction was completed, N-methylaniline (48 mg) and 1-phenylcyclohexene (47 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a pale yellow oily liquid (58 mg, yield 73%).

HRMS (ESI) m/z calculated: _C19H24N [ _M +H] ⁺ : 266.1903; found: 266.1904.

¹ H NMR (400MHz, CDCl ₃ , 298K) δ=7.24 (m, 4H, o-Ph, m-Ph), 7.08 (m, 3H, p-Ph, m-PhN), 6.53 (m, 2H, o -PhN), 3.55 (brs, 1H, NHCH ₃ ), 2.78 (s, 3H, NHCH ₃ ), 2.23 (m, 4H, 2-C ₆ H ₁₀ ), 1.55 (m, 4H, 3-C ₆ H ₁₀ ) ), 1.48 (m, 2H, 4-C ₆ H ₁₀ ).

¹³ C NMR (101MHz, CDCl ₃ , 298K) δ=149.6(i-Ph), 146.9(i-PhN), 137.4(p-PhN), 128.2(o-Ph), 128.1(m-PhN), 127.2( m-Ph), 125.2 (p-Ph), 112.4 (o-PhN), 45.6 (1-C ₆ H ₁₀ ), 37.4 (2-C ₆ H ₁₀ ), 30.9 (NHCH ₃ ), 26.6 (4-C _6H10 ), 23.1 ( _{3 - C6H10} ).

Example 11

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. The reaction was completed, 2-bromo-N-methylaniline (83 mg) and α-methylstyrene (35 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a pale yellow oily liquid (75 mg, yield 82%).

HRMS (ESI) m/z calcd: _C16H19BrN [M+H] ⁺ : _304.0695 ; found: 304.0692.

¹ H NMR (400MHz, CDCl ₃ , 298K) δ=7.38 (m, 1H, 3-PhN), 7.30 (m, 4H, o-Ph, m-Ph), 7.22 (m, 1H, p-Ph), 7.10 (m, 1H, 5-PhN), 6.59 (m, 1H, 6-PhN), 4.28 (brs, 1H, NHCH ₃ ), 2.90 (s, 3H, NHCH ₃ ), 1.69 (s, 6H, CMe ₂ ).

¹³ C NMR (101MHz, CDCl ₃ , 298K) δ=150.7(p-Ph), 143.9(1-PhN), 140.4(4-PhN), 130.6(3-PhN), 128.1(m-PhN), 127.2( 5-PhN), 126.8(o-Ph), 125.7(p-Ph), 110.5(6-PhN), 109.5(2-PhN), 42.2(CMe ₂ ), 31.0(CMe ₂ ), 30.8(NHCH ₃ ) .

Example 12

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. The reaction was completed, 2-methyl-N-methylaniline (55 mg) and α-methylstyrene (35 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a pale yellow oily liquid (66 mg, yield 91%).

HRMS (ESI) m/z calculated: For _C17H22N [M+H] ⁺ : _240.1747 ; found: 240.1749.

¹ H NMR (400MHz, CDCl ₃ , 298K) δ=7.24 (m, 4H, o-Ph, m-Ph), 7.14 (m, 1H, p-Ph), 7.03 (m, 1H, 5-PhN), 6.90 (m, 1H, 3-PhN), 6.52 (m, 1H, 6-PhN), 3.45 (brs, 1H, NHCH ₃ ), 2.86 (s, 3H, NHCH ₃ ), 2.07 (s, 3H, PhCH _{3 )} ), 1.64 (s, 6H, CMe ₂ ).

¹³ C NMR (101 MHz, CDCl ₃ , 298K) δ=151.6(i-Ph), 145.2(1-PhN), 139.2(4-PhN), 128.8(3-PhN), 128.0(m-Ph), 126.9( o-Ph), 125.4(p-Ph), 125.3(5-PhN), 121.7(2-PhN), 108.8(6-PhN), 42.2(CMe ₂ ), 31.1(CMe ₂ ), 31.0(NHCH ₃ ) , 17.8 (PhCH ₃ ).

Example 13

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. The reaction was completed, 2-fluoro-N-methylaniline (56 mg) and α-methylstyrene (35 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a light yellow oily liquid (60 mg, yield 82%).

HRMS (ESI) m/z calculated: For _C16H19F [M+H] ⁺ : _244.1496 ; found: 244.1490.

¹ H NMR (400MHz, CDCl ₃ , 298K) δ=7.23 (m, 4H, o-Ph, m-Ph), 7.16 (m, 1H, p-Ph), 6.89 (m, 1H, 5-PhN), 6.83 (m, 1H, 3-PhN), 6.59 (m, 1H, 6-PhN), 3.81 (brs, 1H, NHCH ₃ ), 2.84 (s, 3H, NHCH ₃ ), 1.63 (s, 6H, CMe ₂ ).

¹³ C NMR (101 MHz, CDCl ₃ , 298K) δ=151.4 (d, J _FC =238.0 Hz, 2-PhN), 150.8 (i-Ph), 139.8 (d, J _FC =5.2 Hz, 4-PhN), 135.5(d, _JFC =12.0Hz,1-PhN),128.1(m-Ph),126.8(o-PhN),125.7(p-Ph),122.5(d, _JFC =3.0Hz,5-PhN) , 113.3 (d, J _FC = 18.8 Hz, 3-PhN), 111.08 (d, J _FC = 3.8 Hz, 6-PhN), 42.3 (CMe ₂ ), 30.9 (CMe ₂ ), 30.5 (NHCH ₃ ).

Example 14

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. The reaction was completed, indoline (54 mg) and α-methylstyrene (35 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a pale yellow oily liquid (59 mg, yield 83%).

HRMS (ESI) m/z calculated: _C17H20N [ _M +H] ⁺ : 238.1590; found: 238.1594.

¹ H NMR (400MHz, CDCl ₃ , 298K) δ=7.25 (m, 4H, o-Ph, m-Ph), 7.16 (m, 1H, p-Ph), 6.97 (m, 1H, 3-Ph), 6.90 (m, 1H, 5-Ph), 6.55 (m, 1H, 6-Ph), 3.65 (brs, 1H, NH), 3.52 (t, ³ J _HH = 8.3 Hz, 2H, NHCH ₂ CH ₂ ), 2.96 (t, ³ J _HH = 8.3 Hz, 2H, NHCH ₂ CH ₂ ), 1.64 (s, 6H, CMe ₂ ).

¹³ C NMR (101MHz, CDCl ₃ , 298K) δ=151.6(i-Ph), 149.4(1-Ph), 141.5(4-Ph), 129.4(2-Ph), 128.0(m-Ph), 126.9( o-Ph), 125.5(5-Ph), 125.4(p-Ph), 123.5(3-Ph), 108.9(6-Ph), 47.7(NHCH ₂ CH ₂ ), 42.5(CMe ₂ ), 31.2(CMe ₂ ), 30.1 (NHCH ₂ CH ₂ ).

Example 15

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. After the reaction was completed, N-ethylaniline (55 mg) and α-methylstyrene (35 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a pale yellow oily liquid (64 mg, yield 89%).

HRMS (ESI) m/z calculated: For _C17H22N [M+H] ⁺ : _240.1747 ; found: 240.1755.

¹ H NMR (400MHz, CDCl ₃ , 298K) δ=7.31 (m, 4H, o-Ph, m-Ph), 7.21 (m, 1H, p-Ph), 7.10 (m, 2H, m-PhN), 6.58 (m, 2H, o-PhN), 3.46 (brs, 1H, NHCH ₂ ), 3.18 (q, ³ J _HH = 7.1 Hz, 2H, CH ₂ CH ₃ ), 1.70 (s, 6H, CMe ₂ ), 1.29 (t, _3JHH =7.2Hz, _3H , ^CH2CH3 ₎ .

¹³ C NMR (101 MHz, CDCl ₃ , 298K) δ=151.4(i-Ph), 146.2(i-PhN), 139.4(p-PhN), 127.9(m-Ph), 127.6(m-PhN), 126.8( o-Ph), 125.4 (p-Ph), 112.4 (o-PhN), 42.1 (CMe2), 38.6 ( _{CH2CH3 )} , 31.0 ( _CMe2 ), 15.0 _{( CH2CH3 )} .

Example 16

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. After the reaction was completed, 3,4-dihydro-2H-1,4-benzothiazine (68 mg) and α-methylstyrene (35 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a light yellow oily liquid (79 mg, yield 91%).

HRMS (ESI) m/z calculated: For C ₁₇ H ₁₉ NNaS[M+Na] ⁺ : 292.1130; found: 292.1137.

¹ H NMR (400MHz, CDCl ₃ , 298K) δ=7.28 (m, 4H, o-Ph, m-Ph), 7.19 (m, 1H, p-Ph), 6.95 (m, 1H, 3-Ph), 6.72 (m, 1H, 5-Ph), 6.39 (m, 1H, 6-Ph), 3.80 (brs, 1H, NH), 3.60 (m, 2H, NHCH ₂ CH ₂ ), 3.07 (m, 2H, NHCH ₂ CH ₂ ), 1.64 (s, 6H, CMe ₂ ).

¹³ C NMR (101MHz, CDCl ₃ , 298K) δ=151.0(i-Ph), 140.7(4-Ph), 139.5(1-Ph), 128.0(m-Ph), 126.8(o-Ph), 125.6( p-Ph), 125.5(3-Ph), 124.6(5-Ph), 115.3(6-Ph), 115.2(2-Ph), 42.4(NHCH ₂ CH ₂ ), 42.2(CMe ₂ ), 30.9(CMe ₂ ), 26.4 ( _{NHCH2CH2 )} .

Example 17

The present embodiment provides a preparation method of a para-alkylated product of aromatic secondary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. After the reaction was completed, diphenylamine (42 mg) and α-methylstyrene (35 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a light yellow oily liquid (79 mg, yield 91%).

HRMS (ESI) m/z calculated: _C21H22N [M+H] ⁺ : _288.1747 ; found: 288.1753.

¹ H NMR (400MHz, CDCl ₃ , 298K) δ = 7.26 (m, 4H, o-Ph, m-Ph), 7.22 (m, 2H, 7-Ph), 7.16 (m, 1H, p-Ph), 7.12(m, 2H, 3-Ph), 7.02(m, 2H, 2-Ph), 6.97(m, 2H, 6-Ph), 6.88(m, 1H, 8-Ph), 5.61(brs, 1H, NH), 1.67 (s, 6H, CMe ₂ ).

¹³ CNMR (101MHz, CDCl ₃ , 298K) δ=151.0(i-Ph), 143.7(4-Ph), 143.6(5-Ph), 140.7(1-Ph), 129.4(7-Ph), 128.1(m -Ph), 127.8(3-Ph), 126.9(o-Ph), 125.7(p-Ph), 120.7(8-Ph), 117.8(6-Ph), 117.5(2-Ph), 42.5(CMe ₂ ), 31.0 (CMe ₂ ).

Example 18

The present embodiment provides a preparation method of a para-alkylated product of an aromatic primary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. The reaction was completed, aniline (42 mg) and α-methylstyrene (35 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a light yellow oily liquid (55 mg, yield 87%).

HRMS (ESI) m/z calculated: _C15H18N [M+H] ⁺ : _212.1434 ; found: 212.1435.

¹ H NMR (400MHz, CDCl ₃ , 298K) δ=7.24 (m, 4H, o-Ph, m-Ph), 7.15 (m, 1H, p-Ph), 7.01 (m, 2H, m-PhN), 6.59 (m, 2H, o-PhN), 3.54 (brs, 2H, _NH2 ), 1.63 (s, 6H, _CMe2 ).

¹³ C NMR (101MHz, CDCl ₃ , 298K) δ=151.3(i-Ph), 144.1(i-PhN), 141.1(p-PhN), 128.0(m-Ph), 127.8(m-PhN), 126.9( o-Ph), 125.5 (p-Ph), 114.9 (o-PhN), 42.3 (CMe ₂ ), 31.0 (CMe ₂ ).

Example 19

The present embodiment provides a preparation method of a para-alkylated product of an aromatic primary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. After the reaction was completed, o-methoxyaniline (55 mg) and α-methylstyrene (35 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a light yellow oily liquid (65 mg, yield 90%).

HRMS (ESI) m/z calculated: For _C16H19NNaO [M+Na] ⁺ : _264.1359 ; found: 264.1369.

¹ H NMR (400MHz, CDCl ₃ , 298K) δ=7.27 (m, 4H, o-Ph, m-Ph), 7.18 (m, 1H, p-Ph), 6.72 (m, 1H, 3-Ph), 6.65 (m, 2H, 5-Ph), 3.76 (s, 3H, _OCH3 ), 3.45 (s, 2H, _NH2 ), 1.68 (s, 6H, _CMe2 ).

¹³ C NMR (101MHz, CDCl ₃ , 298K) δ=151.3(i-Ph), 147.1(2-Ph), 141.4(4-Ph), 133.8(1-Ph), 128.0(o-Ph), 126.8( m-Ph), 125.5(p-Ph), 119.2(3-Ph), 114.6(6-Ph), 109.9(5-Ph), 55.5(OCH ₃ ), 42.7(CMe ₂ ), 31.1(CMe ₂ ) .

Example 20

The present embodiment provides a preparation method of a para-alkylated product of an aromatic primary amine, and its reaction route and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. After the reaction was completed, o-chloroaniline (55 mg) and α-methylstyrene (35 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a light yellow oily liquid (57 mg, yield 79%).

HRMS (ESI) m/z calculated: For _C17H21NNa [M+Na] ⁺ : _262.1566 ; found: 262.1570.

¹ H NMR (400MHz, CDCl ₃ , 298K) δ=7.33 (m, 4H, o-Ph, m-Ph), 7.29 (m, 1H, p-Ph), 6.95 (m, 2H, m-PhN), 3.47 (brs, 2H, _NH2 ), 2.27 (s, 6H, _PhCH3 ), 1.78 (s, 6H, _CMe2 ).

¹³ C NMR (101MHz, CDCl ₃ , 298K) δ=151.5(i-Ph), 140.4(i-PhN), 140.3(p-PhN), 128.0(m-Ph), 126.9(m-PhN), 126.8( o-Ph), 125.4 (p-Ph), 121.3 (o-PhN), 42.1 (CMe ₂ ), 31.1 (CMe ₂ ), 18.0 (PhCH ₃ ).

Example 21

The present embodiment provides a preparation method of a para-alkylated product of hydrazine, and its reaction scheme and specific steps are respectively as follows:

Weigh L1 (17 mg), [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ] (24 mg), dissolve in toluene, and react at room temperature for 30 minutes. The reaction was completed, phenylhydrazine (49 mg) and α-methylstyrene (35 mg) were added, and the mixture was heated at 120° C. for 36 hours. After the reaction was completed, the toluene was drained to obtain an oily residue, which was separated by column chromatography to obtain a pale yellow oily liquid (73 mg, yield 91%).

HRMS (ESI) m/z calculated: For _C15H18N2Na [M ₊ Na] ⁺ : _249.1362 ; found: 249.1367.

¹ H NMR (400MHz, CDCl ₃ , 298K) δ=7.23 (m, 4H, o-Ph, m-Ph), 7.15 (m, 1H, p-Ph), 7.01 (m, 2H, m-PhN), 6.59 (m, 2H, o-PhN), 3.54 (brs, 2H, _NHNH2 ), 1.63 (s, 6H, _CMe2 ).

¹³ C NMR (101MHz, CDCl ₃ , 298K) δ=151.3(i-Ph), 144.1(i-PhN), 141.1(p-PhN), 128.0(m-Ph), 127.8(m-PhN), 126.9( o-Ph), 125.5 (p-Ph), 114.9 (o-PhN), 42.3 (CMe ₂ ), 31.0 (CMe ₂ ).

In the above embodiment, the amount of catalyst L1 can not only be 10 mol%, but also can be adjusted between 1-20 mol%. In addition to [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ], the co-catalyst can also use [Ph ₃ C][B(C ₆ F ₅ ) ₄ ] or B(C ₆ F ₅ ) ₃ , the amount of which is not only It can be 10 mol%, and can also be adjusted between 1-20 mol%. The reaction temperature can also be adjusted between 60-150°C.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. It should be pointed out that for those skilled in the art, some improvements can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims (8)

1. the application of scandium-containing rare earth catalyst in catalyzing aromatic amine para-selective alkylation reaction, described reaction is the addition reaction of aromatic amine and olefin, wherein, the structural formula of described scandium-containing rare earth catalyst is as follows:

, the aromatic amine is an aromatic primary amine or an aromatic secondary amine whose structural formula is shown in formula (1), and the structural formula of the olefin is shown in formula (2):

,

;in, R ¹ is hydrogen, phenyl or C ₁ -C ₁₀ alkyl; R ² is hydrogen, C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, phenyl or halogen; and R ² cannot be substituted at the para position; X is a methylene group or a sulfur atom, and n1 is any value from 0 to 4; R ³ is a C ₁ -C ₂₀ alkyl group, a phenyl group, or forms a ring with R ⁵ through several methylene groups, and the number of methylene groups n2 is any value in 1-4; R ⁴ is hydrogen, _C1 - _C20 alkyl, phenyl, thienyl, benzofuranyl or substituted aryl, and the substituent of the substituted aryl is C1-C10 alkoxy, halogen; R ⁵ is hydrogen, methyl or methylene; R ⁶ is hydrogen. 2. The application according to claim 1, wherein the reaction temperature is 60-150°C. 3. The application according to claim 1 or 2, wherein the amount of the scandium-containing rare earth catalyst is 1-20 mol% of the olefin. 4. a preparation method of the aromatic amine of para-alkylation, is characterized in that, comprises the following steps: The aromatic amine of formula (1) and the olefin of formula (2) are reacted in an organic solvent at 60-150 ° C under the catalysis of scandium-containing rare earth catalyst and co-catalyst to obtain the para-alkylated aromatic Amine, wherein, the structural formula of the scandium-containing rare earth catalyst is as follows:

; The co-catalyst is [PhNHMe ₂ ][B(C ₆ F ₅ ) ₄ ]; The reaction route is as follows:

;in, R ¹ is hydrogen, phenyl or C ₁ -C ₁₀ alkyl; R ² is hydrogen, C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy, phenyl or halogen; and R ² cannot be substituted at the para position; X is a methylene group or a sulfur atom, and n1 is any value from 0 to 4; R ³ is a C ₁ -C ₂₀ alkyl group, a phenyl group, or forms a ring with R ⁵ through several methylene groups, and the number of methylene groups n2 is any value in 1-4; R ⁴ is hydrogen, _C1 - _C20 alkyl, phenyl, thienyl, benzofuranyl or substituted aryl, and the substituent of the substituted aryl is C1-C10 alkoxy, halogen; R ⁵ is hydrogen, methyl or methylene; R ⁶ is hydrogen. 5 . The preparation method according to claim 4 , wherein the amount of the co-catalyst is 1-20 mol % of the olefin. 6 . 6 . The preparation method according to claim 4 , wherein the amount of the scandium-containing rare earth catalyst is 1-20 mol % of the total reactants. 7 . 7. preparation method according to claim 4 is characterized in that: described aromatic amine is N -methylaniline, 2-bromo- N -methylaniline, 2-methyl- N -methylaniline, 2- Fluoro- N -methylaniline, indoline, N -ethylaniline, 3,4-dihydro-2H-1,4-benzothiazine, diphenylamine, aniline, o-methoxyaniline, o-chloroaniline or phenylhydrazine. 8. The preparation method according to claim 4, wherein the olefin is α-methylstyrene, 4-methoxy-α-methylstyrene, 4-chloro-α-methylstyrene , 3-bromo-α-methylstyrene, α-propylstyrene, 1,1-stilbene styrene, 2-isopropenylthiophene, 2-(α-methylvinyl)benzofuran, 2-phenylbut-2-ene or 1-phenylcyclohexene.