Phosphirene

Phosphirene is the hypothetical organophosphorus compound with the formula C2H2PH. As the simplest cyclic, unsaturated organophosphorus compound, phosphirene is the prototype of a family of related compounds that have attracted attention from researchers.

Phosphirenes, that is substituted phosphirene compounds where one or more of the H's are replaced by organic substituents, are far more commonly discussed than the parent phosphirene. The first example of a phosphirene, 1,2,3-triphenylphosphirene was prepared via trapping of the phosphinidine complex Mo(CO)5PPh with diphenylacetylene.

Placement of the double bond between the carbon atoms provides a 1Hphosphirene in which the phosphorus center is bonded to two carbon atoms and a hydrogen atom. Alternatively, placement of the double bond between the phosphorus center and a carbon atom generates a 2H-phosphirene. The first 2H-phosphirene was synthesized as early as 1987 by Regitz group. However, the chemistry of 2H-phosphirenes was relatively dormant until a series of reports by Stephan group.