Asymmetric alkoxycarbonylation hydroxycarbonylation

ASYMMETRIC HYDROFORMYLATION, HYDROXYCARBONYLATION, AND ALKOXYCARBONYLATION FOR STEREOSELECTIVE SYNTHESIS... 

Asymmetric Hydroformylation, Hydroxycarbonylation, and Alkoxycarbonylation for Stereoselective Synthesis... 

Abstract The use of Co building block in presence of water or an alcohol to functionalise alkenes by hydroxycarbonylation or alkoxycarbonylation reactions is reviewed in this chapter. The hydroxyl groups can be present in the substrate itself so cascade reactions can occur. Palladium precursors are largely involved in these reactions and this analysis of the literature focuses on the mechanisms involving Pd(0), Pd(H)(X)L2, PdX2 and an oxidant like CuCl systems. Introduction of chiral L or L2 ligands or even the presence of chiral carbon atoms in the substrate lead to asymmetric carbonylation reactions. 

Asymmetric hydrogenation-based processes using a highly active and stereoselective catalyst generate relatively little waste. The asymmetric hydrogenation of readily preparable a-hydroxycarbonyl- or tz-alkoxycarbonyl-suInstituted enamrdes has frequently been applied to the preparation of unnatural a-amrno acids with a wide variety of side chains since the successful application of L-Dopa (Scheme 9.4) [13h]. 

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