In-plane aromaticity in double group transfer reactions.

The main features of double group transfer reactions have been studied under the density-functional theory framework. It is found that a wide range of structure-types and processes including type II-dyotropic reactions and the Meerwein-Ponndorf-Verley reduction take place via highly synchronous in-plane aromatic transition structures. Actually, the orbital topology of these saddle points is equivalent to that which corresponds to a D2h-symmetric aromatic molecule such as pyrazine.