Abstract
N
-(Phenoxymethyl)- and
N
-(phenylthiomethyl)-benzotriazoles are versatile substrates for the preparation of benzofurans and benzothiophenes by insertion reactions of their anions into alkyl and aryl aldehydes and
in situ
cyclization of the α-aryloxy and α-arylthio ketones thus formed.
N
-(Naphthyloxy)- and
N
-(naphthylthio)-benzotriazoles are similarly efficient precursors for naphthofurans and naphthothiophenes.