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.