RU2156770C2 - Method of preparing 1-(dialkylamino)-2-phenyl (alkyl)alumacyclopropanes - Google Patents

Abstract

FIELD: chemical industry. SUBSTANCE: described is method of preparing new 1- (dialkylamino)-2-phenyl(alkyl)alumacyclopropanes of formula I:

1 wherein R is n-C₄H₁₀,n-C₆H₁₃,R¹-Ph,n-C₆H₁₃,n-C₈H₁₇ and are useful in fine organic and organometallic synthesis. Method comprises reacting alpha-olefin

with dialkylamino dichloroalane R₂N-AlCl₂ and metallic magnesium at weight ratio of 10:(10- 14):(10-14), respectively, in the presence of tetraisopropaneoxy titanium, tetrabutoxy titanium or titanocene dichloride catalyst in amount of 2-6 mole % with respect to alpha-olefin in argon atmosphere under normal conditions in tetrahydrofuran. Reaction time is 6-10 hours. Total yield of the desired products is 62-84 %. Method makes it possible to prepare new 1- (dialkylamino)-2-phenyl(alkyl)alumacyclopropanes having high regioselectivity. EFFECT: more efficient preparation method. 12 ex, 1 tbl

Description

где R = н-C₄H₉, н -C₆H₁₃;
R' = Ph, н-C₆H₁₃, н-C₈H₁₇.The invention relates to methods for producing new organoaluminum compounds, specifically to a method for producing 1- (dialkylamino) -2-phenyl (alkyl) aluminacyclopropanes of the general formula (1):

where R = n-C ₄ H ₉ , n-C ₆ H ₁₃ ;
R '= Ph, n-C ₆ H ₁₃ , n-C ₈ H ₁₇ .

 The proposed method can find application in fine organic as well as in organometallic synthesis.

 The known method / U. M. Dzhemilev, A.G. Ibragimov, A.P. Zolotarev, R.R. Muslukhov, G.A. Tolstikov, Izv. USSR Academy of Sciences (Ser. Chem. N 12, 1990, S. 2831-2841 / for the preparation of a disubstituted N-containing aluminacyclopentane of the general formula (2).

реакцией триэтилалюминия (Et₃Al) с диэтил-2E,7-октадиениламином в присутствии катализатора Cp₂ZrCl₂ при комнатной температуре за 16 часов с выходом 87% по схеме:

Известным способом синтезировать 1-(диалкиламино)-2-фенил(алкил)алюмациклопропаны (1) не представляется возможным.

the reaction of triethylaluminum (Et ₃ Al) with diethyl-2E, 7-octadienylamine in the presence of a Cp ₂ ZrCl ₂ catalyst at room temperature for 16 hours with a yield of 87% according to the scheme:

It is not possible to synthesize 1- (dialkylamino) -2-phenyl (alkyl) aluminacyclopropanes (1) in a known manner.

где R = н-C₃H₇, н-C₅H₁₁, н -C₈H₁₇,
реакцией α-олефинов (1-октен, 1-гексен, 1-ундецен) с диэтиламиндихлораланом (Et₂N - AlCl₂) в присутствии металлического магния (порошок) и катализатора (5 мол.%) Cp₂ZrCl₂ при температуре 20^oC за 8 часов в ТГФ с выходом ~75% по схеме:

R = н - C₃H₇, н - C₅H₁₁, н - C₈H₁₇,
Известным способом не могут быть получены 1-(диалкиламино)-2-фенил(алкил)алюмациклопропаны (1).The known method / UM Dzhemilev, AG Ibragimov, AB Morozov. Mendeleev Commun. 1992, No. 1, P. 26-28 / for the preparation of 1- (dialkylamino) -trans-3,4-dialkyl substituted aluminacyclopentanes of the general formula (3):

where R = n-C ₃ H ₇ , n-C ₅ H ₁₁ , n-C ₈ H ₁₇ ,
the reaction of α-olefins (1-octene, 1-hexene, 1-undecene) with diethylamine dichloralan (Et ₂ N - AlCl ₂ ) in the presence of magnesium metal (powder) and catalyst (5 mol%) Cp ₂ ZrCl ₂ at a temperature of 20 ^o C for 8 hours in THF with a yield of ~ 75% according to the scheme:

R = n - C ₃ H ₇ , n - C ₅ H ₁₁ , n - C ₈ H ₁₇ ,
In a known manner, 1- (dialkylamino) -2-phenyl (alkyl) aluminacyclopropanes (1) cannot be obtained.

 Thus, in the literature there is absolutely no information on the regioselective synthesis of 1- (dialkylamino) -2-phenyl (alkyl) aluminacyclopropanes.

 A method for the regioselective synthesis of new types of organoaluminum compounds, namely 1- (dialkylamino) -2-phenyl- (alkyl) aluminacyclopropanes (1), is proposed.

где R' = Ph, н - C₆H₁₃, н - C₈H₁₇ с диалкиламиндихлораланами общей формулы R₂N-AlCl₂, где R = н - C₄H₉, н - C₆H₁₃, и металлическим магнием (порошок), взятыми в мольном соотношении

= 10: (10-14): (10-14), преимущественно 10:12:12, в присутствии тетраизопропоксититана (Ti(OPrⁱ)₄) /или тетрабутоксититана (Ti(OBuⁿ)₄), или титаноцендихлорида (Cp₂TiCl₂)/ в количестве 2-6 мол.% по отношению к α-олефину, предпочтительно 4 мол.%, в атмосфере аргона при комнатной температуре (22-23^oC) и нормальном давлении в ТГФ. Время реакции 6-10 часов, предпочтительно 8 часов. Общий выход целевых продуктов 62-84%. Реакция протекает по схеме:

R = н-C₄H₉, н - C₆H₁₃,
R'=Ph, н - C₆H₁₃, н - C₈H₁₇, [Ti] = Ti(OPrⁱ)₄, Ti(OBu)ⁿ ₄, Cp₂TiCl₂
1-(Диалкиламино)-2-фенил(алкил)-алюмациклопропаны (1) образуются только лишь с участием амидов алюминия под действием титановых катализаторов Ti(OPrⁱ)₄, Ti(OBu)₄, Cp₂TiCl₂. В присутствии других соединений алюминия (например, i-Bu₂AlH, i-Bu₃Al, i-Bu₂AlCl, AlEt₃, AlEt₂Cl, EtO-AlCl₂) или другого катализатора (например, Zr(acac)₄, Zr(OBu)₄, Pd(acac)₂, Ni(acac)₂, FeCl₃) целевые продукты (1) не образуются.The proposed method is carried out by the interaction of α-alefins of the General formula

where R '= Ph, n - C ₆ H ₁₃ , n - C ₈ H ₁₇ with dialkylamine dichloralanes of the general formula R ₂ N-AlCl ₂ , where R = n - C ₄ H ₉ , n - C ₆ H ₁₃ , and metal magnesium (powder) taken in molar ratio

= 10: (10-14): (10-14), preferably 10:12:12, in the presence of tetraisopropoxy titanium (Ti (OPr ⁱ ) ₄ ) / or tetrabutoxy titanium (Ti (OBu ⁿ ) ₄ ), or titanocene dichloride (Cp ₂ TiCl ₂ ) / in an amount of 2-6 mol.% With respect to the α-olefin, preferably 4 mol.%, In an argon atmosphere at room temperature (22-23 ^o C) and normal pressure in THF. The reaction time is 6-10 hours, preferably 8 hours. The total yield of the target products is 62-84%. The reaction proceeds according to the scheme:

R = n-C ₄ H ₉ , n - C ₆ H ₁₃ ,
R '= Ph, n - C ₆ H ₁₃ , n - C ₈ H ₁₇ , [Ti] = Ti (OPr ⁱ ) ₄ , Ti (OBu) ⁿ ₄ , Cp ₂ TiCl ₂
1- (Dialkylamino) -2-phenyl (alkyl) -alumacyclopropanes (1) are formed only with the participation of aluminum amides under the influence of titanium catalysts Ti (OPr ⁱ ) ₄ , Ti (OBu) ₄ , Cp ₂ TiCl ₂ . In the presence of other aluminum compounds (e.g. i-Bu ₂ AlH, i-Bu ₃ Al, i-Bu ₂ AlCl, AlEt ₃ , AlEt ₂ Cl, EtO-AlCl ₂ ) or another catalyst (e.g. Zr (acac) ₄ , Zr (OBu) ₄ , Pd (acac) ₂ , Ni (acac) ₂ , FeCl ₃ ) the target products (1) are not formed.

Carrying out the specified reaction in the presence of a titanium catalyst [Ti] more than 6 mol. % does not lead to a significant increase in the yield of target products. The use of a catalyst of less than 2 mol% decreases the yield of 1- (dialkylamino) -2-phenyl (alkyl) aluminacyclopropanes (1), which is apparently associated with a decrease in catalytically active centers in the reaction mass. The experiments were carried out at room temperature (22-23 ^o C). At a higher temperature (for example, 65 ^o C) there is no increase in the yield of the target products, and at a lower temperature (for example, 0 ^o C) the reaction rate decreases.

A change in the ratio of the starting reagents in the direction of increasing the content of dialkylaminodichloralanes (R ₂ N-AlCl ₂ ) or with respect to the starting α-olefin does not significantly increase the yield of the target products (1).

Significant differences of the proposed method:
1. The proposed method uses titanium-containing catalysts (Ti (OPr ⁱ ) ₄ , Ti (OBu ⁿ ) ₄ , Cp ₂ ZrCl ₂ ), which determine the formation of substituted aluminacyclopropanes (1). In the known method, a zirconium-containing catalyst (Cp ₂ ZrCl ₂ ) is used, which causes the formation of exclusively trans-3,4-substituted aluminacyclopentanes (3).

The proposed method has the following advantages:
1. The method allows to obtain with high regioselectivity 1- (dialkylamino) -2-phenyl (alkyl) aluminacyclopropanes (1), the synthesis of which is not described in the literature.

The method is illustrated by the following examples:
Example 1. In a 50 ml glass reactor mounted on a magnetic stirrer in an argon atmosphere, 10 ml of THF, 10 mmol of styrene, 12 mmol of magnesium (powder), 12 mmol of n-dihexylaminodichloralane (n-C ₆ H ₁₃ ) ₂ N-AlCl are placed ₂ and 0.4 mmol Ti (OPr ⁱ ) ₄ , stirred for 8 hours. Get individual 1- (n-dihexylamino) -2-phenylalumacyclopropane (1) with a total yield of 76%.

Спектр ЯМР ¹³C (δ , м.д.) 1,2-дидейтероэтилбензола (4): 15,41 т (J_13 C-D = 22 Гц, C¹), 28,58 т (J_13C-D = 33 Гц, C²), 141,90 с (C³), 127,83д (C⁴), 128,44д (C⁵), 125.63д (C⁶).The yield of the target products was determined by hydrolysis products. The hydrolysis of 1- (di-n-hexylamino) -2-phenylalumacyclopropane (1) produces di-n-hexylamine and ethylbenzene, identified by comparison with known samples, while deuterolysis (1) 1,2-dideuteroethylbenzene (4) was prepared according to the scheme:

¹³ C NMR spectrum (δ, ppm) of 1,2-dideuteroethylbenzene (4): 15.41 t (J _{13 CD} = 22 Hz, C ¹ ), 28.58 t (J _13C-D = 33 Hz, C ² ), 141.90 s (C ³ ), 127.83 d (C ⁴ ), 128.44 d (C ⁵ ), 125.63 d (C ⁶ ).

 Other examples confirming the method are given in table. 1.

The reaction was carried out at room temperature (22-23 ^o C) in THF. The temperature increase is not advisable, because there is no significant increase in the yield of target products. At lower temperatures (for example, 0 ^° C.), the reaction rate decreases.

Literature
1. W. M. Dzhemilev, A.G. Ibragimov, A.P. Zolotarev, R.R. Muslukhov, G.A. Tolstikov. Izv. USSR Academy of Sciences. Ser. Chem. N 12, 1990.S. 2831-2841.

 2. U.M. Jhemilev, A.G. Ibragimov, A.B. Morozov, Mendeleev Commun. 1992, No. 1, P. 26-28.

Claims (1)

The method of obtaining 1- (dialkylamino) -2-phenyl (alkyl) aluminacyclopropanes of General formula I

where R is n-C ₄ H ₉ , n-C ₆ H ₁₃ ;
R '- Ph, n-C ₆ H ₁₃ , n-C ₈ H ₁₇ ,
characterized in that α is an olefin of the General formula

where R 'is described above,
are reacted with dialkylamine dichloralan of the general formula
R ₂ N -AlCl ₂ ,
where R is described above
and metallic magnesium in a molar ratio

equal to 10: (10-14) :( 10-14), respectively, in the presence of a catalyst of tetraisopropoxy titanium, tetrabutoxy titanium or titanocene dichloride in an amount of 2 to 6 mol. % and the reaction is carried out in an argon atmosphere under normal conditions for 6 to 10 hours

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