Highly Selective Hydrogenation Promoted by Nickel(0) Nanoparticles

Significance

The authors have reported the highly stereoselective cis semihydrogenation of internal alkynes and semihydrogenation of terminal alkynes based on in situ generation of nickel(0) nanoparticles and molecular hydrogen. Thus, the various internal alkynes and terminal alkynes were reduced to the corresponding alkenes in 62-99% yield by using a reductive system composed of anhydrous NiCl₂, lithium, a catalytic amount of DTBB and an alcohol (eq. 1). The complete hydrogenation of internal and terminal alkynes to alkanes, semihydrogenation of dienes to alkenes, hydrogenation of alkenes to alkanes were also demonstrated by using a similar procedure with regulated amount of lithium and alcohol.