Nickel-Catalyzed Sodium Hypophosphite-Participated Direct Hydrophosphonylation of Alkyne toward H-Phosphinates.

The traditional methods for the synthesis of phosphinate esters use phosphorus trichloride (PCl3) as the phosphorous source, resulting in procedures that are often highly polluting and energy intensive. The search for an alternative approach that is both mild and environmentally friendly is a challenging, yet highly rewarding task in modern chemistry. Herein, we use an inorganic phosphorous-containing species, NaH2PO2, to serve as the source of phosphorous that participates directly in the nickel-catalyzed selective alkyne hydrophosphonylation reaction. The transformation was achieved in a multicomponent fashion and at room temperature, and most importantly, the H-phosphinate product generated is an advanced intermediate which can be readily converted into diverse phosphinate derivatives, including those bearing new P-C, P-S, P-N, P-Se, and P-O bonds, thus providing a complimentary method to classic phosphinate ester synthesis techniques.

Lewis acid-catalyzed Pudovik reaction-phospha-Brook rearrangement sequence to access phosphoric esters.

Herein, we report a Lewis acid-catalyzed Pudovik reaction-phospha-Brook rearrangement sequence between diarylphosphonates or -phosphinates and α-pyridinealdehydes to access valuable phosphoric ester compounds. This transformation provides an extended substrate scope that is complementary to similar previously reported base-catalyzed transformations.

Direct Allylic C(sp3)-H Alkylation with 2-Naphthols via Cooperative Palladium and Copper Catalysis: Construction of Cyclohexadienones with Quaternary Carbon Centers.

Oxidative allylic C-H alkylation with 2-naphthols was accomplished with excellent chemoselectivities and broad substrate scope through Pd(PPh3)4/Cu(MeCN)4PF6 cooperative catalysis under mild base-free conditions. Special tolerance was observed with peptides, allowing late-stage modifications of peptides. The transformation provides a general protocol to obtain functionalized cyclohexadienones with quaternary carbon centers under two alternative sets of conditions and serves as a complementary catalysis system for the dearomatization of 2-naphthols.

Copper-catalyzed intermolecular amidation of 8-methylquinolines with N-fluoroarylsulfonimides via Csp(3)-H activation.

An efficient copper-catalyzed C-H amidation of 8-methylquinolines with N-fluoroarylsulfonimides via Csp(3)-H activation is described. The reaction proceeds with high functional group tolerance, providing a novel approach to valuable quinolin-8-ylmethanamine derivatives in the absence of an additional oxidant.