Cyclopropenes for the Stepwise Synthesis of 1,2,4,5-Tetraarylbenzenes via 1,4-Cyclohexadienes.

This paper describes a synthetic approach to the synthesis of 1,2,4,5-tetraarylbenzene derivatives from cyclopropenes. The Lewis acid-mediated dimerization of cyclopropenes gives tricyclo[3.1.0.0 2,4 ]hexane derivatives. The subsequent thermal ring-opening reaction under solvent-free conditions gives 1,4-cyclohexadienes bearing quaternary carbons. The novel Br 2 -mediated oxidative rearrangement of 1,4-cyclohexadienes takes place to give 1,2,4,5-tetraarylbenzene derivatives in high to excellent yields.