Alkynylcarbenes: generation, properties, and application in organic synthesis

The present review systematizes the currently known data on the methods for generating various types of alkynylcarbenes, information on their structure, properties, and reactions. Special attention is given to such approaches to alkynylcarbenes as decomposition of the corresponding diazo compounds and arylsulfonylhydrazone salts, photolysis of 3H-pyrazoles, thermolysis of aziridinylimines, as well as numerous processes that involve based-induced elimination reactions. Data on the structure and reactivity studies of a number of alkynylcarbenes under matrix isolation conditions and the examples of application of these intermediates for the directed introduction of the alkynyl moieties into organic compounds of different classes via (1+2)-cycloaddition and insertion reactions are presented.