Borohydride exchange resin-nickel boride

The tributyltin hydride-mediated carbon-carbon bond formation via radical addition and cyclization of alkyl halides with alkenes has often been a choice for construction of various organic molecules [1], However, the requirement for high-temperature initiators or photo initiation and the difficulties associated with purification of the products from tributyltin halides tend to limit the widespread use of these methods, despite the efforts to make the methods easier [Ic, 2], Recently, nickel-mediated radical additions and cyclizations have been introduced as promising alternatives to the tributyltin hydride methods. These are the nickel powder-acetic acid method for cyclization of haloamides to y-lactams, y -lactams and in-dolones, the borohydride exchange resin-nickel boride method for radical addition, nickel-catalyzed electroreductive cyclization and nickel-catalyzed Kharasch addition of polyhalo compounds. 

Borohydride Exchange Resin-Nickel Boride (cat.) Method... 

Primary amines are obtained (8 examples, 68-94%) on exposing oximes to the borohydride exchange resin-NijOAclj (nickel boride should be formed upon admixture) in methanol. Mixed anhydrides of the type RC(0)0C(0)0Et are reduced selectively to alcohols. ... 

Ruthenium catalyst impregnated onto an ion exchange resin may serve as a catalyst for the hydrolysis of sodium borohydride [99]. Other catalyst formulations reported in the literature are metal halides such as nickel and cobalt chloride, colloidal platinum, active carbon, raney nickel, fluorinated partides of magnesium-based material [100] and nickel boride [281]. Zhang et al. reported that nickel powder is an active catalyst under conditions of a batch reactor [282]. With some time delay, the reaction started from ambient conditions. 

---