Other reactions catalyzed by transition-metal complexes

2 Other Reactions Catalyzed by Transition-metal Complexes 

Recently, transition-metal complexes have been reported as efficient catalysts for the addition of metal reagents, including magnesium, aluminium, silicon, zinc, germanium, and 

2 Cross-coupling of Organoboron Compounds with Organic Halides 

The additions proceed regioselectively in favor of terminal boron adducts to produce (Z)-l-alkenylboron compounds through a syn addition of the X-B bond to 1-alkynes. The mechanism is fundamentally different from the uncatalyzed process and is postulated to proceed through the oxidative addition of the X-B bonds (X = H, RS, Y2B) to the transition-metal complex [M(0)] to form X-M-BY-, species (28), followed by the migratory cis insertion 

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Two or three decades ago, no clear conceptual (mechanistic) or practical (experimental) bridge existed between homogeneous and heterogeneous catalysis. In some of his earliest work at Mobil, Werner demonstrated that hydroformylation, carbonylation, and other reactions catalyzed by transition metal complexes were accomphshed equally by heterogeneous catalysis when these complexes were anchored to solid organic resins. 

Prior chapters have covered the use of transition metals in asymmetric hydrogenations ( 6.2 and 7.1), hydroborations ( 7.3), hydrosilylations and hydro-cyanations ( 6.3, 6.4, 7.4 and 7.5), cyclopropanations ( 7.19), aldol reactions ( 6.11), allylations of carbanions ( 5.3.2), and some sigmatropic rearrangements ( 10.3). This chapter covers other reactions catalyzed by transition metal complexes including coupling of organometallic reagents with vinyl, aryl or allyl derivatives, Heck reactions allylamine isomerizations, some allylation reactions, car-bene insertions into C-H bonds and Pauson-Khand reactions. 

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