Synthesis of Highly Functionalized Chiral Benzopyrano[3,4-c]pyrrolidines Bearing Five Contiguous Stereogenic Centers
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- 作者：Toru Sato ; Tomoya Miyazaki ; Takayoshi Arai
- 刊名：Journal of Organic Chemistry
- 出版年：2015
- 出版时间：October 16, 2015
- 年：2015
- 卷：80
- 期：20
- 页码：10346-10352
- 全文大小：458K
- ISSN：1520-6904
文摘
A chiral bis(imidazolidine)pyridine-Cu complex smoothly catalyzed the asymmetric [3 + 2] cycloaddition reaction of 伪,尾-unsaturated ester-containing nitroalkenes with imino esters to give endo-pyrrolidine products in a highly enantioselective manner while maintaining the 伪,尾-unsaturated ester functionality. Subsequent intramolecular diastereoselective cyclizations of the obtained pyrrolidine products were accomplished by treatment with KF/Al2O3 in toluene/EtOH (4:1) to give highly functionalized benzopyrano[3,4-c]pyrrolidines bearing five contiguous stereogenic centers.