An efficient synthesis of chiral phosphinyl oxide pyrrolidines and their application to asymmetric direct aldol reactions
作者:Xue-Wei Liu、Thanh Nguyen Le、Yunpeng Lu、Yongjun Xiao、Jimei Ma、Xingwei Li
DOI:10.1039/b811581h
日期:——
Chiral pyrrolidine-based phosphinyl oxides were synthesized and their performance as organocatalysts for asymmetricdirectaldolreactions was evaluated. High enantioselectivities and diastereoselectivies were achieved for a range of cyclic ketones and aromatic aldehydes.
to >99 % enantiomeric excess (ee) have been obtained by proline catalysis in excellent yields under experimentally simple solvent-free conditions. Efficient mixing of all the components is accomplished by applying a mechanochemical technique (ballmilling). The catalysis is air and moisture tolerant and can be performed with non-purified starting materials. Even mixtures of solely solid compounds react
Ficin-catalyzed asymmetric aldol reactions of heterocyclic ketones with aldehydes
作者:Jian-Ping Fu、Na Gao、Yang Yang、Zhi Guan、Yan-Hong He
DOI:10.1016/j.molcatb.2013.06.016
日期:2013.12
Ficin from fig tree latex displayed a promiscuous activity to catalyze the direct asymmetric aldol reactions of heterocyclic ketones with aromatic aldehydes. Ficin showed good substrate adaptability to different heterocyclic ketones containing nitrogen, oxygen or sulfur. The enantioselectivities up to 81% ee and diastereoselectivities up to 86:14 (anti/syn) were achieved under the optimized reaction conditions. (C) 2013 Elsevier B.V. All rights reserved.
The application of a structurally simple, recyclable, and large-scale l-prolinamide catalyst for asymmetric aldol reactions
作者:Zhi Guan、Yuan Luo、Bao-Qiang Zhang、Krystal Heinen、Da-Cheng Yang、Yan-Hong He
DOI:10.1016/j.tetasy.2014.04.009
日期:2014.5
With heterocyclic ketones or cyclohexanone, the aldolreactions gave products in high yields and with respectable enantioselectivities (87–99% ee) and diastereoselectivities (up to >99:1 anti/syn). The catalyst could be recycled and reused up to seven times resulting in good yields and with good selectivities. This catalyst is also efficient in large-scale reactions with the enantioselectivities remaining