A Facile Construction of Bisheterocyclic Methane Scaffolds through Palladium-Catalyzed Domino Cyclization

Main observation and conclusion A convenient palladium-catalyzed domino cyclization reaction for the construction of bis(benzofuranyl)methane scaffolds bearing an all-carbon quaternary center has been described. In the cascade process, one C(sp(2))-O bond, two C(sp(2))-C(sp(3)) bonds as well as two benzofuran rings are formed in a single synthetic sequence. The approach shows wide scope of substrates and good functional-group tolerance. Moreover, this methodology is successfully extended to the synthesis of benzofuranyl methyl chromane derivatives.

Automated summary

This study presents a convenient palladium-catalyzed domino cyclization reaction for the synthesis of bis(benzofuranyl)methane scaffolds bearing all-carbon quaternary center, in which multiple bonds and rings are formed in a single synthetic sequence through a cascade reaction. The approach demonstrates broad substrate scope and good functional-group tolerance, and has been successfully applied to the synthesis of benzofuranyl methyl chromane derivatives.