Cascade Carbopalladation Reaction between Alkynes and gem-Dibromoolefins: Facile Access to Monoannelated Pentalenes

A carbopalladation cascade reaction of easily accessible gem-dibromoolefins and alkynes furnishes monobenzo- and mononaphthopentalenes. The new chromophores accessed by this short route exhibit small HOMO–LUMO gaps and redox amphoteric behavior with tunable redox potentials.以易得的偕二溴烯烃（gem-dibromoolefins）与炔烃为底物，通过碳钯化级联反应可合成单苯并戊搭烯与单萘并戊搭烯。通过该简洁合成路线获得的新型生色团展现出较小的HOMO-LUMO能隙与氧化还原两性行为，且其氧化还原电位可调控。