Divergent enantioselective pathways in the catalytic asymmetric addition of diethylzinc to aldehydes in the presence and absence of titanium tetraisopropoxide

被引：17

作者：

Dean, Melissa A. ^{[1
]}

Hitchcock, Shawn R. ^{[1
]}

机构：

[1] Illinois State Univ, Dept Chem, Normal, IL 61790 USA

来源：

TETRAHEDRON-ASYMMETRY | 2008年 / 19卷 / 22期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1016/j.tetasy.2008.10.033

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

The stereochemical outcome of the asymmetric addition of diethylzinc to aldehydes catalyzed by (R,R)-hydrobenzoin can be influenced by the absence or presence of Ti(O-iPr)(4). The enantiomeric ratios obtained in the absence of Ti(O-iPr)(4) favor the (S)-enantiomer, whereas the ratios obtained from the use of Ti(O-iPr)(4) favor the formation of the (R)-enantiomer. The formation of the opposite enantiomers is attributed to the different transition states mediated by either zinc or titanium. (C) 2008 Elsevier Ltd. All rights reserved.

引用

页码：2563 / 2567

页数：5

共 37 条

[31] CATALYTIC AND STOICHIOMETRIC ENANTIOSELECTIVE ADDITION OF DIETHYLZINC TO ALDEHYDES USING A NOVEL CHIRAL SPIROTITANATE [J].

SCHMIDT, B ;

SEEBACH, D .

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH, 1991, 30 (01) :99-101

[32] Reversal of stereochemistry in diethylzinc addition to aldehydes by a simple change of the backbone substituent in L-serine derived ligands [J].

Sibi, MP ;

Chen, JX ;

Cook, GR .

TETRAHEDRON LETTERS, 1999, 40 (17) :3301-3304

[33] Reactions of aldehydes with diethylzinc catalysed by polymer-supported ephedrine and camphor derivatives: comparisons of enantiomeric excesses achieved with various supports: optimisation of support parameters to enable high enantiomeric excesses to be obtained [J].

Sung, DWL ;

Hodge, P ;

Stratford, PW .

JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, 1999, (11) :1463-1472

[34] Titanium-catalyzed enantioselective additions of alkyl groups to aldehydes: Mechanistic studies and new concepts in asymmetric catalysis [J].

Walsh, PJ .

ACCOUNTS OF CHEMICAL RESEARCH, 2003, 36 (10) :739-749

[35] Mechanism of asymmetric dialkylzinc addition to aldehydes catalyzed by titanium(IV) complexes of N-sulfonylated β-amino alcohols [J].

Wu, KH ;

Gau, HM .

ORGANOMETALLICS, 2004, 23 (03) :580-588

[36]

Zhang FY, 1997, TETRAHEDRON-ASYMMETR, V8, P585, DOI 10.1016/S0957-4166(97)00024-4

[37]

ZHANG XM, 1995, TETRAHEDRON LETT, V36, P4947

← 1 2 3 4 →