A new variant of the Reformatsky-Claisen rearrangement is described. The reaction of substituted allyl alpha-bromoacetates with indium and indium(III) chloride under ultrasonication provides a general entry into the functionalized synthon. (C) 2011 Elsevier Ltd. All rights reserved.
Chemo- and Enantioselective Pd/B Hybrid Catalysis for the Construction of Acyclic Quaternary Carbons: Migratory Allylation of <i>O</i>-Allyl Esters to α-<i>C</i>-Allyl Carboxylic Acids
We describe herein the asymmetric synthesis of α-allyl carboxylic acids containing an α-quaternarystereocenter by a chiral hybrid catalyst system comprising palladium and boron complexes. The reaction proceeded through palladium-catalyzed ionization of α,α-disubstituted O-allyl esters for the generation of chiral π-allyl palladium complex as an electrophile, boron-catalyzed enolization of the carboxylate