The ene reaction in the chemistry of low-coordinate phosphorus - part 127

The ene reaction belongs to one of the simplest and most versatile reaction categories in organic chemistry. Recently ene reactions involving compounds of low-coordinate phosphorus, phospha-ene reactions, have found wide application in the synthesis of different classes of organophosphorus compounds. For phospha-ene reactions, four main types are currently known which involve the employment of phosphaalkenes, iminophosphines and phosphaalkynes. Also included are retro-phospha-ene reactions, which reveal access to short-lived and highly reactive phosphaalkenes. The experimentally observed regiochemistry is in agreement with MO calculations, carried out on the simplest parent reactions of type I-IV.