Formation and rearrangement of adducts from benzyne and substituted 2,1,3-benzoselenadiazoles

Abstract

A series of 5-(1,2-benzoselenazol-3-yl)pentadienonitrile derivatives (2) has been prepared by addition of benzyne to substituted 2,1,3-benzoselenadiazoles. Some of these adducts rearrange either thermally or photochemically to give 2-(2-pyridyl)phenyl selenocyanates (7), which are reduced to 2-phenylpyridine derivatives (6) or hydrolysed to give ultimately, diselenides (9). The crystal structure of one benzyne adduct (2b) is reported and the mechanism of its rearrangement discussed.