Multi-component Reactions with Aldehydes and Ketones

Multi-component Reactions with Aldehydes and Ketones 

Multi-component reactions open a direct access to poly-functional deriva- 

On the other hand, Jamison and co-workers focused on the development of reactions involving allenes as source of chirality. They described the enantio-and regioselective coupling of various allenes, aldehydes and silanes catalyzed by [(IPr)2Ni] to produce (Z)-silylated allyl alcohols (Equation (10.30)).  

The reaction was extended to the coupling of alkenes and isocyanates to provide a,p-acrylamides. The most active catalyst was [(IPr)Ni] that allowed a good regioselectivity at the 2-position of the olefin (Equation (10.31)) and deprotection of the obtained products afforded the corresponding primary amides. 

More interestingly, the same authors used their procedure for highly selective couplings of alkenes and aldehydes (Equation (10.32)). The catalytic system combined a strong a donor IPr and a strong tt acceptor P(OPh)3. This combination was proposed to produce a synergistic relationship by reducing the electron density at the coordinatively unsaturated Ni centre, which would accelerate the elimination step in the catalytic cycle. 

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