960化工网
9-Amino-(9-deoxy)cinchona alkaloid-derived new chiral phase-transfer catalysts†
Wenwen Peng,Jingwei Wan,Bing Xie,Xuebing Ma
Organic & Biomolecular Chemistry Pub Date : 08/19/2014 00:00:00 , DOI:10.1039/C4OB01648C
Abstract

A new class of 9-amino-(9-deoxy)cinchona alkaloid-derived chiral phase-transfer catalysts bearing amino groups was developed by using known cinchona alkaloids as the starting materials. Due to the transformation of the 9-hydroxyl group into a 9-amino functional group, the catalytic performances were significantly improved in comparison with the corresponding first generation phase-transfer catalysts, and excellent yields (92–99%) and high enantioselectivities (87–96% ee) were achieved in the benchmark asymmetric α-alkylation of glycine Schiff base. Based on the special contribution of the amino group to the high yield and enantioselectivity, the possible catalytic mechanism was conjectured.

Graphical abstract: 9-Amino-(9-deoxy)cinchona alkaloid-derived new chiral phase-transfer catalysts
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