Reactions of Dichlorocarbene with Phosphorus Compounds in Low Coordination (Low σ) States

Reactions of low coordinated phosphorus compounds with dichlorocarbene and successive conversions of the resulting phosphiranes to phosphacumulenes are reviewed. Sterically protected diphosphenes reacted with dichlorocarbene to give the corresponding dichlorodiphosphiranes, which reacted with methyllithium to give 1, 3-diphosphaallenes. Similarly, the reaction of (E)-or (Z)-2-phenyl-l-(2, 4, 6-tri-t-butylphenyl)-l-phosphaethenes with dichlorocarbene afforded trans-phosphirane, which was converted to 1-phosphaallene. In some cases, the reactions of dichlorocarbene with 1-phosphaallenes, 1, 3-diphosphaallenes, or 1-phosphabutatrienes resulted in the formation of the rearranged products. Reactions of dichlorocarbene with other phosphorus species in low coordination states such as l-aza-3-phosphaallene, 1, 4-diphosphabutatriene, or phosphaalkyne are also described.