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Carboxylic Derivatives - Reduction (Diborane Reduction)

  • Page ID
    1224
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    Diborane, B2H6

    The reducing characteristics of diborane (disassociated to BH3 in ether or THF solution) were first introduced as addition reactions to alkenes and alkynes. This remains a primary application of this reagent, but it also effects rapid and complete reduction of carboxylic acids, amides and nitriles. Other than LAH, this reagent provides one of the best methods for reducing carboxylic acids to 1º-alcohols.

    1. (1)

    R–CO2H + BH3
    ether soln.
    arrow2_s1qw.gif

    [RCH2O–B]
    H2O2
    arrow2_y36o.gif

    RCH2–OH

    (2)

    R–C≡N + BH3
    ether soln.
    arrow2_bv42.gif

    RCH2–NH–B
    H2O
    arrow2.gif

    RCH2–NH2

    This page titled Carboxylic Derivatives - Reduction (Diborane Reduction) is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by William Reusch.