Asymmetric Addition of Alkoxy Ethynyl Anion to Chiral N-Sulfinyl Imines
摘要:
The addition of lithiated ynol ethers to chiral N-sulfinyl imines proceeds in high yield and diastereoselectivity. The selectivity is completely reversed by the addition of boron trifluoride. These alkoxypropargyl sulfinamides can be reduced to afford enol ethers, selectively oxidized to busyl derivatives, or the ynol ether can be hydrolyzed to afford beta-amino esters.
A General Aminocatalytic Method for the Synthesis of Aldimines
摘要:
A general and efficient biomimetic method for the synthesis of aldimines from aldehydes and compounds bearing the NH2 group in the presence of pyrrolidine as a catalyst has been developed. These organocatalytic reactions, based on the application of the concept of nucleophilic catalysis, proceed with outstanding yields in the absence of acids and metals under simple conditions and minimum experimental manipulation. The method has been mainly applied to the synthesis of N-sulfinyl and N-sulfonyl imines, but its general validity has been proven with the preparation of representative N-phosphinoyl, N-alkyl, and N-aryl imines. These unprecedented reactions, which presumably occur via iminium activation without requiring acidic conditions, are an interesting and competitive alternative to the classical methods for preparing aldimines.
Highly efficient asymmetric construction of novel indolines and tetrahydroquinoline derivatives <i>via</i> aza-Barbier/C–N coupling reaction
作者:Tao Guo、Bin-Hua Yuan、Wen-Jie Liu
DOI:10.1039/c7ob02891a
日期:——
Highly stereoselectivesyntheses of chiral indolines and tetrahydroquinolines are achieved by combining the asymmetric Zn-mediated allylation of chiral N-tert-butanesulfinyl imines with efficient intramolecular C–N cross-coupling. Herein, the advantages of such a synthetic strategy are illustrated by the synthesis of indolines and tetrahydroquinolines with quaternary stereocenters and multi-substituted