Intramolecular 1,1-carboboration versus intermolecular FLP addition in reactions of boranes and bis(phenylethynyl)telluroether

Abstract

Reactions of boranes with Te(CCPh)₂ proceed via initial intermolecular 1,1-carboboration followed by either an intramolecular carboboration or an FLP addition to a second molecule of the intermediate, yielding 1-bora-4-tellurocyclohexa-2,5-diene heterocycles or tricylic derivatives of 1,4-ditellurocyclohexa-2,5-diene, respectively. The latter species is also shown to convert to the former upon heating.