A New Entry to the Ethynylation of Azaaromatics Using Bis(tributylstannyl)acetylene in the Presence of Alkyl chloroformate

Article abstract of DOI:10.1016/S0040-4020(01)89318-2

Unstable N-alkoxycarbonyl quaternary salts of azaaromatics were trapped in situ by bis(tributylstannyl)acetylene followed by the treatment with trifluoroacetic acid to give 2-ethynyl adducts in good yields.The same compounds were obtained only in low yields when ethynyltributyltin was used as a nucleophile.The reaction was revealed to be available for various aromatics including pyridine, pyrazine, imidazole, thiazole, oxazole, and benzodiazines.