Large-scale synthesis of 1,1,3,3,6-pentamethyl-1,3-disilaindan-5-ol via a CoBr2/Zn-catalyzed [2+2+2] cycloaddition reaction

An efficient scaled-up synthesis of 11 utilizing a CoBr2/Zn-catalyzed [2+2+2] cycloaddition reaction has been developed, allowing the preparation of compound 2, a building block for sila-substituted drugs, on a multi-gram scale.