Borohydride exchange resin , alkyne hydrogenation

Triple bonds can also be selectively reduced to double bonds with DIBAL-H, " with activated zinc (see 12-36), with hydrogen and Bi2B-borohydride exchange resin, ° or (internal triple bonds only) with alkali metals (Na, Li) in liquid ammonia or a low-molecular-weight amine.Terminal alkynes are not reduced by the Na—NH3 procedure because they are converted to acetylide ions under these conditions. However, terminal triple bonds can be reduced to double bonds by the... 

Pd metal deposited on borohydride exchange resin (BER) has been used as a catalyst to reduce various alkynes to alkenes in essentially quantitative yieldsJ Ultrasound was also reported to benefit the selective hydrogenation of alkynes to alkenes by decreasing the reduction times from 8-20 h to 0.5-4... 

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