Insights into unusual stability of 5‐membered‐ring endocyclic benzyl carbocations in aqueous solution

Abstract

The acyclic o-oxygen benzyl carbocation 1, the 6-membered-ring endocyclic o-oxygen benzyl carbocation 2, and the 5-membered-ring endocyclic o-oxygen benzyl carbocation 3 were used as model compounds to get insights into the general phenomenon for the unusual stability of the 5-membered-ring endocyclic benzyl carbocations in aqueous solution. The hydride-ion affinities of 1, 2, and 3 in gas phase, acetonitrile, and DMSO were calculated and com-