Transition metal catalysts alkene cross-coupling reactions

Catalytic hydroboration of alkenes and alkynes can be achieved by the reaction of dialkoxyboranes such as pinacolborane 55 and catecholborane 56 in the presence of transition metal catalysts such as CpjZrHCl, Rh(PPh3)3Cl, or Rh(PPh3)2COCl, (Scheme 28.14). This reaction is of particular significance because it readily provides alkyl/vinylboronates directly in one step for further utility in Suzuki-Miyaura cross-coupling reaction. 

Previously acrylonitrile had proved to be inert towards transition metal catalysed cross- and self-metathesis using ill-defined multicomponent catalysts [lib]. Using the molybdenum catalyst, however, acrylonitrile was successfully cross-metathesised with a range of alkyl-substituted alkenes in yields of40-90% (with the exception of 4-bromobut-l-ene, which gave a yield of 17.5%). A dinitrile product formed from self-metathesis of the acrylonitrile was not observed in any of the reactions and significant formation (>10%) of self-metathesis products of the second alkene was only observed in a couple of reactions. 

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