Copper-mediated 1,4-Conjugate Addition of Boronic Acids and Indoles to Vinylidenebisphosphonate leading to<i>gem</i>-Bisphosphonates as Potential Antiresorption Bone Drugs
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 boronicacids and indoles to vinylidenebisphosphonate tetraethyl ester.