NEW ORGANOPHOSPHORUS LIGANDS - CYCLOPROPANATION AND OTHER REACTIONS OF CUMULENES BEARING DIPHENYLPHOSPHANYL SUBSTITUENTS

Hydrophosphorylation of 1,4-bis(diphenylphosphanyl)butadiyne with diph enylphosphane leads to the butadiene (Ph(2)P)(2)C=CH-CH=C(PPh(2))(2) ( 1). Treatment of 1 with dimethylsulfonium methylide gives the vinylcyc lopropane (Ph(2)P)(2)C=CH-CH(CH2)C(PPh(2))(2) (2). Compound 2 reacts w ith aqueous hydrogen peroxide, elemental sulfur, or selenium to afford the tetrachalcogenides (Ph(2)XP)(2)C= CH-CH(CH2)C(PXPh(2))(2) with X = O (3), X = S (4), X = Se (5), respectively. While the tetraphosphane 1 and the vinylcyclopropane compound 2 cannot be converted into a bis -(cyclopropyl) compound with an excess of Me(2)S=CH2, the tetrasulfide 4 readily affords a mixture of (1R,1'R)-/(1S,1'S)and ,2,2',2'-tetraki s(diphenylthiophosphinyl)-1,1'-bi- cyclopropyl (6, 7) in good yield. T reatment of 1,1,4,4-tetrakis-(diphenylphosphanyl)butatriene with dimet hylsulfonium methylide leads to the vinylidenecyclopropane (Ph(2)P)(2) C= C=C(CH2)C(PPh(2))(2) (8). Compound 8 is converted into its tetrasul fide (Ph(2)SP)(2)C=C=C(CH2)C(PSPh(2))(2) (9) by treatment with element al sulfur. The crystal structures of 1, 2, 4, 7, and 8 have been deter mined by single-crystal X-ray diffraction.