Conformer-specific polar cycloaddition of dibromobutadiene with trapped propene ions

Abstract

Identifying a concerted or stepwise mechanism in Diels–Alder reactions is experimentally challenging. Here the authors demonstrate the coexistence of both mechanisms in the reaction of 2,3-dibromobuta-1,3-diene with propene ions, using a conformationally controlled molecular beam reacting with trapped ions and ab initio computations