Copper-mediated 1,4-Conjugate Addition of Boronic Acids and Indoles to Vinylidenebisphosphonate leading to gem-Bisphosphonates as Potential Antiresorption Bone Drugs

A wide range of gem-bisphosphonate tetraethyl esters as precursors for bisphosphonic acids, which are potent inhibitors of bone resorption, bearing alkyl, aryl, and indole substituents in the β position were prepared through the CuII-catalyzed 1,4-conjugate addition of boronic acids and indoles to vinylidenebisphosphonate tetraethyl ester.

A wide range of gem-bisphosphonate tetraethyl esters as precursors for bisphosphonic acids, which are potent inhibitors of bone resorption, bearing alkyl, aryl, and indole substituents in the position were prepared through the Cu-II-catalyzed 1,4-conjugate addition of boronic acids and indoles to vinylidenebisphosphonate tetraethyl ester.