Cyclization of Bisphosphines to Phosphacycles via the Cleavage of Two Carbon–Phosphorus Bonds by Nickel Catalysis

Abstract

The nickel-catalyzed cyclization of bisphosphine derivatives to form various phosphacycles is reported. The reaction proceeds via the cleavage of two carbon–phosphorus bonds of the bisphosphine. Unlike the previously reported palladium catalysts, the use of nickel as a catalyst allows for the cyclization that requires C­(alkyl)–P bond cleavage. A phospha-nickelacycle intermediate was successfully isolated and characterized by X-ray crystallography.

Direct Synthesis of Dibenzophospholes from Biaryls by Double C–P Bond Formation via Phosphenium Dication Equivalents

“…The most classical and most reliable protocols are the substitution reactions of the dilithiated biaryl compounds with dichlorophosphines RPCl 2 (Scheme , path a) and radical substitution reactions of dibromobiaryls with the specially designed RP­(SnMe 3 ) 2 reagents (path b) . Recently, the cyclization of biarylphosphine derivatives via C–H, C–X, or C–P bond cleavage has also been developed as the simpler and relatively functional group-tolerated alternative strategy (path c). However, the procedures mentioned above still suffer from the limited functional group compatibility and somewhat tedious preparation of prefunctionalized starting substrates and/or reagents.…”

Aryne-Induced SNAr/Dearylation Strategy for the Synthesis of Fluorinated Dibenzophospholes from Triarylphosphines via a P(V) Intermediate

“…Although this reaction is intriguing and potentially useful, the yields were a maximum of 15%, and the mechanism for the reaction remains unclear. Our group has recently developed synthetic methods for preparing dibenzophospholes from biarylphosphine or bisphosphine derivatives via the cleavage of C–P bonds by transition-metal catalysis (Scheme b). However, all of these reactions are limited to intramolecular processes, which hampers the rapid construction of diverse products and requires transition-metal catalysts.…”

Synthesis, structural characterization, and optical properties of benzo[f]naphtho[2,3-b]phosphoindoles

“…The synthesis, crystal structure, and dynamic behavior of benzo[e]naphtho [2,1-b]phosphindole (A) with the C 2 symmetry axis on the binaphthyl skeleton have been reported [9][10][11]. Synthetic approaches for phosphine oxide B [12][13][14], alkylated products C [15], and transition metal complexes D [16,17] have also been developed. However, for isomers E [18,19] and G [20], only the synthetic method for pentavalent phosphine oxides has been reported.…”