Enantioselective synthesis of diaryl aziridines using tetrahydrothiophene-based chiral sulfides as organocatalysts
作者:Meng-Ting Huang、Hsin-Yi Wu、Rong-Jie Chein
DOI:10.1039/c3cc47550f
日期:——
This work describes catalytic and asymmetricaziridinations (15 examples, 95-98% ee) of benzyl bromide and imines via the imino Corey-Chaykovsky reaction using (thiolan-2-yl)diarylmethanol benzyl ether as an organocatalyst. The catalyst and analogues thereof were prepared through an expeditious and efficient synthetic route featuring a double nucleophilic substitution and Shi epoxidation as key steps
Organoselenium-Catalyzed Asymmetric Cyclopropanations of (<i>E</i>)-Chalcones
作者:Pei-Tung Cheng、Yu-Hsun Tseng、Rong-Jie Chein
DOI:10.1021/acs.orglett.1c03243
日期:2021.10.15
compounds were used to catalyze asymmetriccyclopropanation reactions; the selenonium ylide intermediates formed from these selenium-containing catalysts and benzyl bromide efficiently react with (E)-chalcones to give various cyclopropanes (27 examples) with excellent enantioselectivities of ≤99% ee and are the first examples of organoselenium-catalyzed asymmetriccyclopropanations.
我们报告了一类新的基于 ( S )-二苯基(四氢硒酚-2-基) 甲醇的手性四氢硒酚,其由 ( R )-3-(3-溴丙基)-2,2-二苯基环氧乙烷和硒化钠制备。这些手性四氢硒酚类化合物用于催化不对称环丙烷化反应;由这些含硒催化剂和苄基溴形成的硒叶立德中间体与 ( E )-查耳酮有效反应,得到各种环丙烷(27 个实例),具有≤99% ee 的优异对映选择性,是有机硒催化不对称环丙烷化的第一个实例。
(Thiolan-2-yl)diphenylmethyl benzyl ether/N,N′-diarylurea cocatalyzed asymmetric aziridination of cinnamyl bromide and aryl aldimine
作者:Shang-Hua Wang、Rong-Jie Chein
DOI:10.1016/j.tet.2014.12.063
日期:2016.5
A dual catalyst system using THT-based chiral sulfide 2a and H-bond donor 10a was developed for the asymmetric imino Corey-Chaykovsky reaction. Under the optimum reaction conditions, cinnamyl bromide reacted with a wide scope of N-diphenylphosphinic aldimines, to give the major trans-aryl cinnamyl aziridines with up to 98% ee. The role of H-bond donor 10a was demonstrated empirically as well. (C) 2014 Elsevier Ltd. All rights reserved.
Concise Synthesis of Chiral N-Benzyl-α,α-Diarylprolinols through Shi Asymmetric Epoxidation
作者:Chengsheng Ge、Jie Li、Hai Zhou、Jiangsen Weng、Mingwen Wang、Wujie Tu
DOI:10.1055/s-0033-1340825
日期:——
A concise and practical synthesis of chiral N-benzyl-alpha,alpha-diaryl-2-prolinols was developed through Shi asymmetric epoxidation, followed by double nucleophilic substitution of bromo-containing olefins. A series of enantioenriched N-benzyl-alpha,alpha-diaryl-2-prolinols were obtained with excellent enantioselectivities (96% ee) in moderate to good yields (40-76% yield). For the first time, enantiopure N-benzyl-alpha,alpha-diphenyl-2-prolinol was obtained from bromo-containing olefin using this methodology.