Enantioselective synthesis of allenecarboxylates from phenyl acetates through CC bond forming reactions
摘要:
A variety of optically active 4,4-disubstituted allenecarboxylic acid methyl esters were prepared from simple alpha,alpha -disubstituted phenyl acetate through base treatment of the esters to generate ketenes, followed by successive Horner-Wadsworth-Emmons reaction. The transformation was further developed as a one-pot procedure with satisfactory yields and high enantioselectivity. (C) 2001 EIsevier Science Ltd. All rights reserved.
A variety of optically active 4,4-disubstituted allenecarboxylic acid methyl esters were prepared from simple alpha,alpha -disubstituted phenyl acetate through base treatment of the esters to generate ketenes, followed by successive Horner-Wadsworth-Emmons reaction. The transformation was further developed as a one-pot procedure with satisfactory yields and high enantioselectivity. (C) 2001 EIsevier Science Ltd. All rights reserved.
Phase-Transfer and Other Types of Catalysis with Cyclopropenium Ions
作者:Jeffrey S. Bandar、Anont Tanaset、Tristan H. Lambert
DOI:10.1002/chem.201500124
日期:2015.5.11
This work establishes the cyclopropeniumion as a viable platform for efficient phase‐transfer catalysis of a diverse range of organic transformations. The amenability of these catalysts to large‐scale synthesis and structural modification is demonstrated. Evaluation of the molecular structure of an optimal catalyst reveals some unique structural features of these systems. Finally, a discussion of