1-Tri-n-butylstannylcyclobutene, obtained from 1-bromocyclobutene by lithium/bromine exchange and transmetalation with chloro-tri-n-butylstannane, could be effectively converted with aryl halides into 1-arylcyclobutenes by the Stille cross-coupling procedure. Hetero-aryl halides like 2-bromopyridine and 2-iodothiophene were also successfully coupled, and in 1, 3, 5-tribromobenzene, 1, 2, 4, 5-tetrabromobenzene and hexabromobenzene all bromine ...