Diastereoselectivity in Iodotrimethylsilane-promoted Conjugate Additions of Organocopper Reagents to Chiral α,β-Unsaturated Imides and Amides

Article abstract of DOI:10.1016/0040-4039(95)00336-B

Conjugate additions of MeCu, PhCu and BuCu to the chiral enoylimides 2 a-c in the presence of iodotrimethylsilane and lithium iodide in THF give the adducts, 4a-c in yields above 90percent and diastereoselectivities from 80 to 93percent.The dominating diastereomers are different from those formed with LiR2Cu/TMSCl or in copper(I)-mediated addition of Grignard reagents.Corresponding additions to enoyl-amides of O-tritylprolinol also give high yields of conjugate adducts, but lower diastereoselectivities, with dominating configuration in the acyl part opposite to those from the imides.