Phosphonium Ion-Tethered Secondary Amines for Chemospecific 5-<i>Enolexo</i> Aldol Condensations of 6-Ketoaldehydes
作者:Akash Sugunan、V. M. Aparna、Goreti Rajendar
DOI:10.1021/acs.joc.3c02285
日期:2023.12.15
targets five-membered carbo- and heterocyclic aldehydes, involving unusual aldehydes as donors and ketones as acceptors. Especially, enolizable aryl keto aldehydes and heteroatom-embedded ketoaldehydes exclusively produced cyclized products with our new catalyst, while other catalysts provided predominantly self-aldol or decomposedproducts. The scope and diversity of the method demonstrated by synthesizing
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.
Rational Design of Organocatalyst: Highly Stereoselective Michael Addition of Cyclic Ketones to Nitroolefins
作者:Bin Tan、Xiaofei Zeng、Yunpeng Lu、Pei Juan Chua、Guofu Zhong
DOI:10.1021/ol900330p
日期:2009.5.7
A remarkable organocatalyst that facilitates the asymmetric Michaeladdition of cyclic ketones to nitroolefins in excellent stereoselectivities (98:2 to >99:1 dr, 92% to >99% ee) has been developed and afforded various types of optically active nitroalkane derivatives of synthetic and biological importance. The extremely simple and practical operational procedure at room temperature increases the attractiveness
Readily available (S)-proline-derived organocatalysts for the Lewis acid-mediated Lewis base-catalyzed stereoselective aldol reactions of activated thioesters
phosphinyl oxide groups were easily synthesized in a straightforward procedure by reaction of readily available proline-based scaffolds and phosphinoyl chlorides. The newly synthesized derivatives were employed (0.1 mol equiv) as organocatalysts in the Lewis acid-mediated Lewis base-promoted direct stereoselectivealdolreactions of activated thioesters with aromatic aldehydes, carried out in the presence