Will an isolated Alkyne or an alkene be reduced using sodium borohydride ($\ce{NaBH4}$)?

  • 1
    $\begingroup$ While Nilay's answer is interesting, sodium borohydride itself won't reduce isolated bonds like these. I'm even kinda surprised you'd ask. $\endgroup$
    – Mithoron
    Jun 18 at 17:46

1 Answer 1


Why not?

Alkenes and alkynes are rapidly reduced to the corresponding alkanes using sodium borohydride and acetic acid in the presence of a small amount of palladium catalyst. The heterogeneous reaction is conducted in open air at room temperature. Reactions typically afford conversions to the alkane product of 98% or more within 15 min. The best solvent system was determined to be isopropyl alcohol, though reduction also takes place in solvents such as tetrahydrofuran, chloroform and, with some substrates, even in water. The method described is a convenient alternative to hydrogenations that require an external supply of hydrogen gas.

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Ref.: Anthony T. Tran, Vincent A. Huynh, Emily M. Friz, Sara K. Whitney, David B. Cordes, A general method for the rapid reduction of alkenes and alkynes using sodium borohydride, acetic acid, and palladium, Tetrahedron Letters, Volume 50, Issue 16, 2009, DOI: 2009,10.1016/j.tetlet.2009.02.014.

  • 3
    $\begingroup$ Note - no reaction will occur without the Pd catalyst $\endgroup$
    – Waylander
    Jun 17 at 6:20
  • $\begingroup$ @Waylander that was my real question...if only NaBH4 was used...thanks:) $\endgroup$ Jun 17 at 6:49
  • $\begingroup$ Isn't this more of a reduction with hydrogen produced in situ? $\endgroup$
    – Mithoron
    Jun 18 at 17:44

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