A DFT Study on the Thermal Aryl Migration in Aryliodonium Ylides. Support for a Concerted Mechanism

A DFT study on the intramolecular thermal phenyl migration in iodonium ylides supports a concerted mechanism. In contrast to the two, different than each other, suggested mechanisms, involving only intermediates, this study indicates a single-step, transition-state oneinvolving a five-membered cyclic ringwith no intermediates. The frontier-orbital-controlled migration also confirms the different thermal behavior of two different ylides.