Csp³−P^III Bond Formation via Cross‐Coupling of Umpolung Carbonyls with Phosphine Halides Catalyzed by Nickel

Abstract

A novel method for the formation of Csp3−PIII bonds via the nickel‐catalyzed cross‐coupling of Umpolung carbonyls and phosphine chlorides is reported herein. This process leads to a series of alkylphosphines, which are characterized as sulfides or borane‐phosphine complexes after undergoing further transformation with moderate to good yields. Invaluable free alkylphosphines can be easily obtained by desulfurization or deboration of the products. A possible mechanistic pathway is also discussed. This report represents the first example of using renewable carbonyls as latent organometallic reagent surrogates for cross‐coupling with heteroatom electrophiles.

Direct Synthesis of Tertiary Phosphines via Alkoxide-Mediated Deborylative Phosphination of Organoboronates

“…5 Recently, Li and co-workers developed a Ni-catalyzed crosscoupling of hydrazones and phosphine chloride, providing borane−phosphine complexes in good yields. 6 Indeed, in addition to transition metal-catalyzed processes, several radicalbased approaches have been established for the formation of C(sp 3 )−P bonds. These strategies utilize alkyl halides 7 and aliphatic acids 8 as starting materials, eliminating the need for premade organometallic reagents.…”

“…For example, in 2015, Han described a nickel-catalyzed C–O/P–H cross-coupling reaction that allowed for the synthesis of benzylic phosphonates using alcohol derivatives as readily available starting materials . Recently, Li and co-workers developed a Ni-catalyzed cross-coupling of hydrazones and phosphine chloride, providing borane–phosphine complexes in good yields . Indeed, in addition to transition metal-catalyzed processes, several radical-based approaches have been established for the formation of C­(sp 3 )–P bonds.…”

Reductive Coupling of P(O)–H Compounds and Aldehydes for the General Synthesis of Phosphines and Phosphine Oxides

“…In addition, the direct hydrophosphinylation − or hydrophosphination of alkenes with P–H compounds has also been developed (Scheme c). In recent years, transition-metal-catalyzed C–P bond formation through cross-coupling reactions has been reported by our group and many other research groups (Scheme d). ,,− Though great progress has been made in this field, these processes still rely on the use of expensive metal catalysts and ligands. In addition, the selective construction of a C–P­(III) bond from stable and readily available substrates has been less studied.…”