Direct Assembly of Benzo[e]indoles by Diels-Alder Reaction of Arynes and 2-Vinylpyrroles

A direct synthetic strategy for the construction of benzo[e]indoles by Diels–Alder reaction of 2‐vinylpyrroles and arynes was developed. By introducing CHPh2 as the N‐protecting group, the arynes selectively reacted with the external vinyl group instead of the pyrrole ring itself. A series of substituted benzo[e]indoles were afforded with high selectivity in good yields. A direct and efficient strategy for the construction of the benzo[e]indole skeleton is developed by Diels–Alder reaction of arynes and easily accessible 2‐alkenylpyrroles. By introducing CHPh2 as the N‐protecting group, the arynes can selectively react with the external vinyl group instead of the pyrrole ring itself in a step‐ and atom‐economical manner.