Transition-Metal-Free Diboration Reaction by Activation of Diboron Compounds with Simple Lewis Bases


  • We thank the Ministerio Ciencia e Innovación for funding (CTQ2010-16226, CTQ2008-06549-CO2-02/BQU and Consolider-Ingenio 2010 CSD2006-0003).


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Changing behavior: A nucleophilic sp2 carbene-type boryl moiety, formed upon interaction of tetraalkoxydiboranes and a Lewis base, can attack non-activated C[DOUBLE BOND]C bonds. Computational studies identify the interaction as the overlap between the strongly polarized B[BOND]B σ bond (HOMO) and the antibonding π* orbital (LUMO) of the C[DOUBLE BOND]C bond. Conceptually, the normally electrophilic boron becomes nucleophilic and forces the olefin to act as an electrophile.