Metal-Catalyzed P–C Bond Formation via P–H Oxidative Addition: Fundamentals and Recent Advances

Abstract

Metal-catalyzed addition of P–H bonds to alkenes, alkynes, and other unsaturated substrates in hydrophosphination and related reactions is an atom-economical approach to valuable organophosphorus compounds. Understanding the mechanisms of these processes may enable synthetic improvements and development of new reactions. The first step in several catalytic cycles is P–H oxidative addition to yield intermediate metal hydride complexes bearing M–P bonds. P–C bond formation may occur via substrate insertion into the M–H bond, followed by P–C reductive elimination, or by insertion into the M–P bond and C–H reductive elimination. In an alternative outer-sphere process, nucleophilic attack of a metal–phosphido (M–PR2) group on an unsaturated substrate and proton transfer involving the metal hydride yields the product. This Perspective reviews the mechanistic possibilities, with a focus on the P–H activation step, and recent progress in developing novel catalytic transformations involving P–C bond formation.

Cyclo-Tetrakis(μ-diphenylphosphido)-1,5-bis(tri-tert-butylphosphine)-Tetracopper

“…Metal phosphido compounds are important synthetic intermediates in organophosphorus chemistry [1][2][3]. Most copper phosphido compounds characterized by X-ray crystallography have oligomeric structures [4][5][6][7][8][9][10][11][12][13][14][15] with a few notable exceptions [16,17].…”

The first ring-expanded NHC–copper(i) phosphides as catalysts in the highly selective hydrophosphination of isocyanates

“…The exploitation of metal phosphides is a widespread route to organophosphorus compounds. [1][2][3][4] Beyond their stoichiometric application, catalytic intermediates of the form L n MPR 2 have been integral to a green revolution in organophosphorus chemistry, especially when the metals concerned are Earthabundant first row transition metals (i.e., Fe, Co). These mid-dblock systems, however, are prone to redox-switching and single-electron transfer reactions which, coupled with the stability of phosphorus centred radicals, often result in undesirable side reactions.…”

Investigation of Hydrophosphorylation Reaction of Pentacoordinate Hydrospirophosphorane and Electron‐Deficient Alkenes Catalyzed by Organic Phosphine

“…Furthermore, our group found that pentacoordinate spirophosphorane was a type of potential organocatalyst to catalyze organic reactions [25] . The addition reactions of olefins and tricoordinate or tetracoordinate phosphorus compounds bearing P−H bond have been reported [26–30] . However, to the best of our knowledge, there is few report on the direct pentacoordinate P−C formation through the hydrophosphorylation reaction of olefins [31,32] .…”