Photochemistry of Functionalized Diphosphiranes

Article abstract of DOI:10.1021/jo00309a019

The structure of the functionalized trans-diphosphiranes 1a-e, obtained by reaction of halogenocarbenes with the trans-diphosphene is confirmed by X-ray diffraction.The photolysis of 1a-e lead to the functionalized cis- and trans-1,3-diphosphapropenes 2a-e as major products, via the diphosphiranyl 7 and the diphosphapropenyl 8 radical intermediates.The latter are characterized by ESR spectroscopy using the spin-trap method.The trans configuration of 2a is also confirmed by X-ray diffraction.The mechanism of the ring-opening, involving P-P bond rupture, is discussed.