173220-67-2Relevant academic research and scientific papers
Exploring tertiary enamides as versatile synthons in organic synthesis
Wang, Mei-Xiang
, p. 6039 - 6049 (2015/04/14)
Tertiary enamides have long been thought of as stable and marginally valuable enamine variants in synthesis. This notion has been challenged, however, in recent years. Enabling the regulation of the cross-conjugation system of the tertiary enamides has been successfully shown to enhance delocalization of the nitrogen lone-pair electrons into a carbon-carbon double, thereby reinvigorating the enaminic reactivity of the tertiary enamides. In this article, I summarize the recent advances in the exploration of the nucleophilic reactions of tertiary enamides and their applications in the synthesis of natural products and heterocyclic compounds of biological and pharmaceutical relevance, with a primary focus on our own work.
Highly efficient and concise synthesis of both antipodes of SB204900, clausenamide, neoclausenamide, homoclausenamide and ζ-clausenamide. Implication of biosynthetic pathways of clausena alkaloids
Yang, Luo,Wang, De-Xian,Zheng, Qi-Yu,Pan, Jie,Huang, Zhi-Tang,Wang, Mei-Xiang
experimental part, p. 2628 - 2634 (2009/10/31)
The synthesis of both antipodes of N-methyl-N-[(Z)-styryl]-3-phenyloxirane- 2-carboxamide (SB204900), clausenamide, neoclausenamide, homoclausenamide and ζ-clausenamide have been accomplished using (2S,3R)- and (2R,3S)-3-phenyloxirane-2-carboxamides as the starting materials, and SB204900 was found to be a common precursor to other N-heterocyclic clausena alkaloids. Mediated by Bronsted acids under different conditions, for example, SB204900 underwent efficient and diverse alkene-epoxide cyclization, enamide-epoxide cyclization and arene-epoxide cyclization reactions to produce the five-membered N-heterocyclic neoclausenamide, its 6-epimer, the six-membered N-heterocyclic homoclausenamide and the eight-membered N-heterocyclic ζ-clausenamide, respectively, in good to excellent yields. Regiospecific oxidation of neoclausenamide and its 6-epimer afforded neoclausenamidone. Enolization of neoclausenamidone in the presence of LiOH and the subsequent protonation under kinetic conditions at -78 °C led to the epimerization of neoclausenamidone into clausenamidone. Reduction of clausenamidone using NaBH4 furnished clausenamide in high yield. The Royal Society of Chemistry 2009.
