Simple Modifications for the Facile Preparation of 1,1,2,3,4,4‐Hexaaryl‐1,3‐butadienes

Abstract

A facile preparation of 1,1,2,3,4,4‐hexaaryl‐1,3‐butadienes which are important molecules due to their aggregation‐induced emission (AIE) activity was achieved by simple modifications of the reaction conditions reported in the previous work. In this reaction system, the insertion of alkynes into the palladium−carbon bond will be accelerated by changing the palladium intermediate to the cationic one. When silver nitrate was used, the reaction of diarylalkynes with arylboronic acids took place smoothly under mild reaction conditions without any ligand to give the coupling diene products in excellent yields. On the contrary, the reaction hardly proceeded with silver oxide and silver carbonate. Poly(hexaphenyl‐1,3‐butadiene) (PHB) with a similar molecular weight to the previously prepared one was also synthesized from the reaction of diphenylacetylene with phenyldiboronic acid under mild reaction conditions.