文献类型：期刊文献

英文题名：An Unconventional Redox Cross Claisen Condensation-Aromatization of 4-Hydroxyprolines with Ketones

作者：Tang, Mi[1,2];Sun, Rengwei[1,2];Li, Hao[1,2];Yu, Xinhong[1,2];Wang, Wei[1,2,3]

机构：[1]East China Univ Sci & Technol, State Key Lab Bioengn Reactors, Sch Pharm, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Shanghai Key Lab New Drug Design, Sch Pharm, 130 Meilong Rd, Shanghai 200237, Peoples R China;[3]Univ New Mexico, Dept Chem & Chem Biol, Albuquerque, NM 87131 USA

年份：2017

卷号：82

期号：16

起止页码：8419

外文期刊名：JOURNAL OF ORGANIC CHEMISTRY

收录：;EI(收录号：20173404063918);WOS:【SCI-EXPANDED(收录号:WOS:000408285500008)，CCR-EXPANDED(收录号:WOS:000408285500008)】；

基金：We gratefully acknowledge financial support from the National Natural Science Foundation of China (21476078, X.-H.Y.; and 21372073 and 21572055, W.W.) and National Science Foundation (CHE-1565085, W.W.), and the Science and Technology Commission of Shanghai Municipality (no. 12431900902, X.-H.Y.).

语种：英文

外文关键词：Propionic acid - Cyclization - Condensation - Reaction intermediates - Synthesis (chemical) - Condensation reactions - Carboxylation - Esters - Redox reactions

摘要：Reaction of alpha-aminoacids, particularly proliries and their derivatives with carbonyl compounds via decarboxylative redo); process, is a viable strategy for synthesis Of structurally diverse nitrogen centered heterocyclics. In these processes, the decarboxylation is the essential driving force for the processes. The realiiation of the redox process, without decarboxylation May offer an opportunity to explore new reactions. Herein, we report the discovery of an unprecedented redox Claisen-type condensationaronatization cascade reaction of 4-substituted 4-hydrocypioline,and its esters with unreactive ketones. We found that the use of propionic acid as a catalyst and a co-solvent can change the reaction course. The commonly observed redox decarboxylation and aldol condensation reactions are significantly minimized. Moreover, Unreactive can effectively participate in the,Claisen condensation reaction. The new reactivity enables a redox cyclization via an unconventional, Claisen-type condensation reaction of in situ formed enamine intermediates from ketone precursors with 4-substittited 4-hydroxyproline and its esters as electrophilic acylation partners. Under the reaction conditions, the cascade process,proceeds highly regio- and stereoselectively to afford highly synthetically and biologically valued cis-2,3-dihydro-1H-pyrrolizin-1,ones with a broad substrate scope in efficient 'one-pot' operation, whereas such structures generally require Multiple steps.