Unraveling and Manipulating the Stereospecific Retro-Aldol Reaction in the Organocatalytic Asymmetric Aldol Reaction of Isatin and Cyclohexanone

An l-pyroglutamic acid-derived bifunctional organocatalyst was designed and applied in an organocatalytic asymmetric direct aldol reaction between isatins and cyclohexanone, in which an erosion of enantiomeric excess of aldol adduct was unexpectedly observed. Through closely monitoring the reaction...

Full description

Saved in:
Bibliographic Details
Published in:Organic letters 2018-12, Vol.20 (23), p.7535-7538
Main Authors: Wang, Jing, Deng, Zhi-Xiong, Wang, Chao-Ming, Xia, Peng-Ju, Xiao, Jun-An, Xiang, Hao-Yue, Chen, Xiao-Qing, Yang, Hua
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:An l-pyroglutamic acid-derived bifunctional organocatalyst was designed and applied in an organocatalytic asymmetric direct aldol reaction between isatins and cyclohexanone, in which an erosion of enantiomeric excess of aldol adduct was unexpectedly observed. Through closely monitoring the reaction and performing extensive control experiments, it was determined that the erosion of ee was attributed to a rare stereospecific retro-aldol process. Moreover, effective manipulation of the retro-aldol process by tuning the use of starting materials was ultimately accomplished, leading to evidently upgraded enantioselectivity and functional group tolerance. This study demonstrates the impact of the hidden reaction pathway on the enantioselectivity in asymmetric transformation.
ISSN:1523-7060
1523-7052
DOI:10.1021/acs.orglett.8b03292