A Straightforward and Mild Synthesis of Functionalized 3-Alkynoates

摘要

The methods that have been described to date for the synthesis of 3-alkynoates generally require multiple steps and/ or highly basic reaction conditions.One very attractive route to 3-alkynoates would be by the coupling of readily available terminal alkynes with diazoesters.Unfortunately,in the absence of a catalyst,treatment of alkynes with diazo compounds preferentially generates cyclopropenes and C_(alkyl)- H insertion products.With respect to metal-catalyzed processes,in the presence of rhodium complexes,reactions of terminal alkynes with diazo compounds lead not to insertion into the C_(alkynyl),-H bond,but typically to cyclo-propenation.