Phosphinowethanide Complexes/Metalla-Phospha Heterocycles

Abstract

An overview of recent results in the field of hetero-cycles with incorporated phosphinomethanide moieties is provided in this article. Monophosphinomethanides and Diphosphinomethani-des interact with main group, transition or lanthanoide metal centers to give complexes with chelating ligands of the type M(CP), M(PCP) and M(PCP)M. Insertion of sulfur or selenium into the metal-phosphorus bond is feasible, leading to novel hetero-cycles. Likewise, insertion of C0 into the metal-carbon bond may be achieved, and again, after rearrangement, novel type hetero-cycles can be obtained. The interaction of at least two phosphinomethanide ligands at a metal center may promote oxidative coupling (C-C, P-C, or P-P), methyl transfer, and various kinds of metalation reactions at a C-H functionality. The products again represent novel classes of metalla-phospha heterocycles. The reaction course and thus the type of heterocycles obtained may be tuned by the substitution pattern of the phosphinomethanides and by the choice of the coordination center. Coupling of two M(PCP)M fragments may lead to heterocycles of the type c-M₄(PCP)₂.