Synthesis and Transformation of Bis(silyl)-Substituted Conjugated Vinylallene Compounds.

We develop a copper-catalyzed disilylation of polysubstituted pent-1-en-4-yn-3-yl acetate derivatives, which in one pot furnishes the bis(silyl)-substituted vinylallenes in moderate yields under mild reaction conditions. The reaction shows broad substrate scope and single stereoselectivity. Besides, we develop a method to decrease the electrocyclization temperature of vinylallenes for the synthesis of methylenecyclobutenes by installing bis(silyl) substituents. And the effect of a silyl substituent on electrocyclization of vinylallenes was studied via DFT computation. The synthetic method features broad substrate scope and excellent stereoselectivity.