Synthesis of Di-Substituted Alkynes via Palladium-Catalyzed Decarboxylative Coupling and C-H Activation

摘要

A straightforward methodology for the decarboxylative crosscoupling of aryl bromides and phenylpropiolic acid using a Pd(II)-NHC catalyst has been developed.Various aryl bromides have been successfully transformed into the corresponding disubstituted alkynes using environmentally benign conditions(weak base and ethanol as solvent).This efficient catalytic system also proved useful for the copper-free Sonogashira coupling of aryl and alkenyl bromides with various terminal alkynes.The synthetic utility of these methodologies was highlighted in the synthesis of a polyaromatic compound and various fluoroenynes.