PHOSPHORUS-PHOSPHORUS SINGLE OR DOUBLE BOND FORMATION FROM PCl(3-n)Rn (n=1 or 2) AND A BIS-IMIDAZOLIDINE REDUCING AGENT

Article abstract of DOI:10.1016/S0022-328X(00)99656-6

1,3,1'.3'-Tetraethyl-bis(2,2'-imidazolidene), L₂^Et (I), is a mild homogeneous reducing agent which reduces P-Cl bonds phosphonous or phosphinous chlorides to give compounds with phosphorus-phosphorus bonds.High yields of diphosphines P2R4 are produced from the corresponding phosphinous chlorides (PClR2).Phenyl- and t-butyl-phosphonous dichlorides are reduced to cyclopolyphosphines (PR)n, which appear to be the kinetically controlled products. 2,4,6-Tri(t-butyl)phenylphosphonous dichloride (PArCl2) is reduced to either 1,2-dichloro-1,2,bis(2,4,6-tri-t-butylphenyl)diphosphine (PArCl)2 or trans-bis<(2,4,6-tri-t-butyl)phenyl>diphosphene (P2Ar2) depending on the initial stoichiometry.