Synthetic approaches to both linear and cyclic cyano-substituted phosphines (P∼CN-phosphines) found an industrial application as catalyst precursors, pesticides, herbicides, flame retardants, precursors of aminophosphines etc., are reported. The main synthetic routes include reduction of P=O containing precursors, alkylation of silylphosphines and metal phosphides by halogenoalkyl(aryl)carbonitriles, phosphorylation of the latter ones, decomposition of phosphonium salts and hydrophosphination of cyano-substituted olefins proceeding under non-catalytical conditions and with use of metal complex catalysis. Merits and demerits of each approach are discussed. Phosphines bearing cyano function as an additional coordination site show diverse coordination behavior depending on the phosphine structure and nature of the metal. Four main types of complexes are observed, namely those with P-monodentate coordination, with N-monodentate coordination and complexes where bidentate coordination mode of P and N atoms is realized either at the single metal atom or of bridged type between two different metal atoms. Thus coordination behavior of such P∼CN-ligands relative to transition and non-transition metals, structure features of the complexes obtained and their application in catalytic processes are discussed.
Keywords: hydrophosphination, trichlorosilane, Alkylation, phosphorus-containing products, coordination chemistry, bridging coordination
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