title: Palladium-Catalyzed Direct Dialkenylation of Cage B-H Bonds in o-Carboranes through Cross-Coupling Reactions.
abstract: Palladium-catalyzed direct dialkenylation of cage B(4,5)-H bonds in o-carboranes has been achieved with the help of a carboxylic acid directing group, leading to the preparation of a series of 4,5-[trans-(ArCH=CH)]2-ocarboranes in high yields with excellent regioselectivity. The traceless directing group, eliminated during the course of the reaction, is responsible for controlling regioselectivity and dialkenylation. A possible catalytic cycle is proposed, involving a tandem sequence of Pd(II) -initiated cage B-H activation, alkene insertion, β-H elimination, reductive elimination, and decarboxylation.
authors.affiliation: Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China).
authors.forename: Hairong
authors.initials: H
authors.lastname: Lyu
authors.affiliation: Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China).
authors.forename: Yangjian
authors.initials: Y
authors.lastname: Quan
authors.affiliation: Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China). zxie@cuhk.edu.hk.
authors.forename: Zuowei
authors.initials: Z
authors.lastname: Xie
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D001880:Boranes / Q000737:chemistry*; D002384:Catalysis; D010165:Palladium / Q000737:chemistry*
chemical_list: D000475:Alkenes; D001880:Boranes; D010165:Palladium
keywords: BH activation; alkenylation; carboranes; cross-coupling; palladium catalysis