Ligand Coupling within ?-Sulphurane Intermediates formed in the Reaction of Benzyl 2-Pyridyl and Related Sulphoxides with Grignard reagents
The reaction of benzyl or 1-phenylethyl 2-pyridyl sulphoxide (1) or (18) with a Grignard reagent was found to give the ligand-coupling product, i.e., 2-benzylpyridine or 2-(1-phenylethyl)pyridine (2) or (22) in excellent yield.This coupling reaction was found to proceed whithin the ?-sulphurane formed as an intermediate upon treatment of benzyl 2-pyridyl and related sulphoxides with a Grignard reagent.The stereochemical course of this coupling reaction involves complete retention at the benzylic carbon.