Transition metal-catalyzed alkynylation reactions via alkynyl carbon-carbon bond cleavage

It is of great significance to realize the alkynylation of the reaction since alkynes are widely present in natural products and biologically active molecules. And at the same time alkynes have very rich transformations in synthetic organic chemistry. It is also attractive to functionalize molecules by cleaving inert carbon-carbon bonds albeit with great challenge due to their inherent stability. Recently, significant progress has been made in the cleavage of alkynyl carbon-carbon single bonds for enabling the alkynylation of organic molecules. This review focuses on the recent advances in transition-metal-catalyzed cleavage and transformation of alkynyl carbon-carbon bonds with alkynoic acids, propargylic alcohols, alkynyl esters, and alkynyl ketones.