Michael Addition Reactions of Cyclanone Homologous series with Acrylamide Derivatives: Preferring 2-Carbamoylethyl Derivatives or Ene-lactams
writer：Weifeng Dai, Chaohua Wang, Xi Zhang, Jinming Zhang and Meidong Lang*
keywords：Michael addition reaction, cyclanone, acrylamide, ene-lactam, 2-carbamoylethyl derivative
source：期刊
specific source：Science in China Series B: Chemistry. 2008, 51, 1044-1055
Issue time：2008年
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 employed as the EWGs of the electrophilic alkenes in the Michael addition reaction. In this work, the Michael 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 acrylamides could react with cyclohexanone (CHn) to give the expected 2-carbamoylethyl derivatives; however, 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 α-substituent decides the ratio of resulting isomeric ene-lactams.