Organic letters

Sonogashira coupling reaction with diminished homocoupling

A Elangovan, YH Wang, TI Ho

Index: Elangovan, Arumugasamy; Wang, Yu-Hsiang; Ho, Tong-Ing Organic Letters, 2003 , vol. 5, # 11 p. 1841 - 1844

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Citation Number: 258

Abstract

The side product from homocoupling reaction of two terminal acetylenes in the Sonogashira reaction can be reduced to about 2% using an atmosphere of hydrogen gas diluted with nitrogen or argon. Terminal arylethynes, diarylethynes, and a few new arylpyridylethynes with donor substituents have been synthesized in very good yields. Comparative control experiments suggest that the homocoupling yield is determined by concentration of both ...