Iridium-catalysed regioselective borylation of carboranes via direct B–H activation

• DOI: 10.1038/ncomms14827
• Publication Date: 2017-03-16T10:07:15Z
• Authors: Ruofei Cheng; Zaozao Qiu; Zuowei Xie
• Keywords: Synthon; Borylation; Carborane; Boranes

Abstract Carboranes are carbon–boron molecular clusters, which can be viewed as three-dimensional analogues to benzene. They finding many applications in medicine, materials and organometallic chemistry. On the other hand, their exceptional thermal chemical stabilities, well 3D structures, make them very difficult functionalized, particular regioselective functionalization of BH vertex among ten similar B–H bonds. Here we report a efficient iridium-catalysed borylation cage B(3,6)–H bonds o -carboranes with excellent yields regioselectivity using bis(pinacolato)diboron (B 2 pin ) reagent. Selective B(4)–H has also been achieved by introducing bulky TBDMS ( tert -butyldimethylsilyl) group one carbon vertex. The resultant 3,6-(Bpin) - useful synthons for synthesis wide variety B(3,6)-difunctionalized bearing B– X =O, N, C, I Br)