π–π Chelation controlled chemoselective conjugate addition of lithium dimethylcuprate

✍ Scribed by Naoki Asao; Sunyoung Lee; Yoshinori Yamamoto

• Book ID: 104253035
• Publisher: Elsevier Science
• Year: 2003
• Tongue: French
• Weight: 196 KB
• Volume: 44
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(03)00095-9

✦ Synopsis

The conjugate addition of Me 2 CuLi to ethyl cinnamate derivatives bearing an alkynyl group at the ortho-position, took place preferentially in the presence of the corresponding a,b-unsaturated esters bearing an alkynyl group at the distal position or having no alkynyl groups. The observed chemoselectivity is most probably a reflection of the p-p chelation between p-electrons of the olefinic moiety of the enoates and those of the C-C triple bond located at the proximal position.