Reactions of a phosphavinyl Grignard reagent with main group mono-halide compounds

Abstract

The reactions of a phosphavinyl Grignard reagent, [CyPC(Bu t )MgCl(OEt 2)] Cy=cyclohexyl, with a variety of main group 13, 14 and 16 mono-halide compounds have been investigated. When the Grignard reagent is reacted with bromocatecholborane the terminal phosphavinyl complex, [(C 6H 4O 2)B{C(Bu t )PCy}], is formed. Related terminal phosphavinyl tin and gallium complexes, [R 3Sn{C(Bu t )PCy}], R=Me or Bu n and [IGa{C(Bu t )PCy} 2], have been prepared by similar routes. The reaction of the Grignard reagent with PhSeCl has afforded a new λ 5,λ 5-diphosphete, [{(Bu t )CP(Cy)(SePh)} 2], the mechanism of formation of which is discussed. The preparation of a phosphavinyl selenium compound, [(C 8H 4O 2N)PC(Bu t )(SePh)], is also described. All compounds have been spectroscopically characterised and several have been crystallographically authenticated.