Michael addition reactions of cyclanones with acrylamides: Producing 2-carbamoylethyl derivatives or ene-lactams

• 来源期刊: 中国科学B辑(英文版)
• 年，卷（期）: 2008,（11）
• 页码范围: 1044-1050
• 页数: 7页
• 语种: 英文
• DOI: 10.1007/s11426-008-0095-3

摘要

The electron-withdrawing groups (EWGs) in the electrophilic alkenes employed in the Michael addition reaction are almost only CO2R, CN, COR, NO2, and SO2Ph. Although amides (CONR1R2) are also typical electron-withdrawing groups and are of great importance in organic synthesis, they are scarcely em-ployed as the EWGs of the electrophilic alkenes in the Michael addition reaction. In this work, the Mi-chael reactions of acrylamide and its derivatives with cyclanones were successfully carried out in the presence of enough radical inhibitors. The amide groups play a key role in producing the preferred products. The N-substituted acrylamides, including N-monosubstituted and N,N-disubstituted acryla-mides could react with cyclohexanone (CHn) to give the expected 2-carbamoylethyl derivatives; how-ever, acrylamide reacting with cyclohexanone only produced ene-lactam. Cyclanones also have effects on the products, while the ring size of cyclanones influences the reaction yield and the o-substituent decides the ratio of resulting isomeric ene-lactams.