Sequential Reactions Promoted by Manganese: Completely Stereoselective Synthesis of (<i>E</i>)-α,β-Unsaturated Amides, Ketones, Aldehydes, and Carboxylic Acids
作者:José M. Concellón、Humberto Rodríguez-Solla、Pamela Díaz
DOI:10.1021/jo701417z
日期:2007.10.1
A complete E-selective synthesis of a,alpha,beta-unsaturated amides through a sequential reaction of a range of dichloroamides with a variety of aldehydes promoted by Rieke manganese (Mn*) is reported. A mechanism based on a sequential aldol-type reaction and a completely stereoselective beta-elimination is proposed to explain these results. The unsaturated amides obtained are readily and efficiently transformed into alpha,beta-unsaturated ketones, aldehydes, or carboxylic acids without loss of the diastereoisomeric purity of the C-C double bond.