Stereoselective Rh<sub>2</sub>(<i>S</i>-IBAZ)<sub>4</sub>-Catalyzed Cyclopropanation of Alkenes, Alkynes, and Allenes: Asymmetric Synthesis of Diacceptor Cyclopropylphosphonates and Alkylidenecyclopropanes
作者:Vincent N. G. Lindsay、Dominic Fiset、Philipp J. Gritsch、Soula Azzi、André B. Charette
DOI:10.1021/ja3099728
日期:2013.1.30
A mild and highly stereoselective rhodium(II)-catalyzed cyclopropanation of alkenes, alkynes, and allenes with diacceptor diazo compounds is reported. Using the phosphonate moiety as an efficient trans-directing group, the first catalytic asymmetric route to diacceptor cycloprop(en)ylphosphonates was developed by employing an α-cyano diazophosphonate and Rh(2)(S-IBAZ)(4) as chiral catalyst. The isosteric
报道了一种温和且高度立体选择性的铑 (II) 催化的烯烃、炔烃和丙二烯与二受体重氮化合物的环丙烷化反应。使用膦酸酯部分作为有效的反式导向基团,通过使用 α-氰基重氮膦酸酯和 Rh(2)(S-IBAZ)(4) 作为手性催化剂,开发了第一个催化不对称二受体环丙(烯)基膦酸酯的路线。膦酸和羧酸衍生物的等排特性允许在该过程中替代使用 α-氰基重氮酯,从而以高产率和立体选择性生成 α-氰基环丙(烯)基羧酸酯。利用该系统中涉及的氰基卡宾中间体的特殊反应性,相容底物的范围可以扩展到取代的丙二烯,
7. Azidiniumsalze. 19. Mitteilung [1]. Einführung der Diazogruppe in reaktive Methylenverbindungen mit Azidiniumsalzen
Diazo-Group Transfer to Active Methylene Compounds Using Azidinium Salts
使用重氮盐将重氮基转移至活性亚甲基化合物
Photocatalytic Alkylation of Pyrroles and Indoles with α-Diazo Esters
作者:Łukasz W. Ciszewski、Jakub Durka、Dorota Gryko
DOI:10.1021/acs.orglett.9b02612
日期:2019.9.6
electron-rich aromatic compounds with diazo esters. C-2-alkylated indoles and pyrroles are obtained with good yields even though the photocatalyst loading is as low as 0.075 mol %. For EWG-substituted substrates, the addition of a catalytic amount of N,N-dimethyl-4-methoxyaniline is required. Both EWG-EWG- and EWG-EDG-substituted diazo esters are suitable as alkylatingagents. The reaction selectivity and mechanistic
cyclopropyl ring. Furthermore, the synthetic potential of the developed system has been evaluated. By the application of a chiral secondary amine catalyst, the organocatalytically activated cyclopropanes show an unexpected and highly stereoselective formation of cyclobutanes, functionalizing at the usually inert sites of the donor-acceptor cyclopropane. By the application of 3-olefinic oxindoles and benzofuranone
Catalytic Asymmetric Syntheses of Alkylidenecyclopropanes from Allenoates with Donor‐Acceptor and Diacceptor Diazo Reagents
作者:Yoko Hasegawa、Thomas Cantin、Jonathan Decaens、Samuel Couve‐Bonnaire、André B. Charette、Thomas Poisson、Philippe Jubault
DOI:10.1002/chem.202201438
日期:2022.8.22
Chiral ACPs: The catalytic asymmetric synthesis of alkylidenecyclopropanes from electron-deficient allenes is described. The methodology, using donor-acceptor or diacceptor diazo reagents, catalyzed by a chiral rhodium complex furnished the corresponding ACPs in high yields with excellent diastereo- and enantioselectivities.