Preparation and C-Alkylation of Enantiomerically Pure<i>S</i>-Phenyl Aziridinecarbothioates. On the Structure of Small-Ring Ester Lithium Enolates
作者:Robert Häner、Bernardo Olano、Dieter Seebach
DOI:10.1002/hlca.19870700704
日期:1987.11.4
%, 18 examples; Schemes 1 and 4–6). The configurational stability of the lithiated species is studied, and conclusions about their structures are drawn. Thus, a C(α)-lithiated ester (see L, Scheme 9) or an O-lithiated ‘enolate’ (see M) with pyramidalized C(β)-atom is proposed for the species from levorotatory S-phenyl N-benzylaziridinecarbothioate which does not undergo racemization after 1 h at −60°
Ring-Opening Cycloaddition of Aziridines to Ketenimines
作者:Heiko Maas、Corinne Bensimon、Howard Alper
DOI:10.1021/jo970562+
日期:1998.1.1
The Lewis acid-catalyzed addition of aziridines to ketenimines gave substituted pyrrolidonimines in 47-87% yields. The hard Lewis acid LiClO(4) proved to be superior to the soft [(PhCN)(2)PdCl(2)], affording higher yields under milder conditions. The reaction is regioselective and occurs with complete stereoselectivity using [(PhCN)(2)PdCl(2)] and with a small amount of racemization in the case of
PREPARATION OF PENTAFLUOROSULFANYL (SF5) HETEROCYCLES: PYRROLES AND THIOPHENES
申请人:Zheng Zhaoyun
公开号:US20110040103A1
公开(公告)日:2011-02-17
The subject invention pertains to pentafluorosulfonyl (SF5) substituted pyrroles, thiophenes, 3-pyrrolines and 2,5-dihydrothiophenes, as well as methods for their synthesis.
本发明涉及五氟磺酰(SF5)取代的吡咯、噻吩、3-吡咯烷和2,5-二氢噻吩,以及它们的合成方法。
Preparation of Pentafluorosulfanyl (SF<sub>5</sub>) Pyrrole Carboxylic Acid Esters
作者:William R. Dolbier、Zhaoyun Zheng
DOI:10.1021/jo9007699
日期:2009.8.7
paper, a facile preparation of SF5-substituted pyrrole carboxylic acid esters in good yield is reported. Utilizing the cycloaddition of an azomethine ylide to pentafluorosulfanylalkynes, a series of dihydropyrroles were prepared and oxidized to the respective 1-tert-butyl-4-(pentafluorosulfanyl)pyrrole-2-carboxylic acid esters in good yield. Further treatment of these pyrroles with catalytic triflic
Preparation of optically active aziridine carboxylates by lipase-catalyzed alcoholysis
作者:Monique Martres、Gérard Gil、Alain Méou
DOI:10.1016/s0040-4039(00)78498-x
日期:1994.11
Aziridine carboxylates alcoholysis by lipases depends of the N-substituent. N-alkyl and N-aryl compounds have been resolved with medium to good enantiomeric purity by enzymatic alcoholysis catalyzed by pig pancreatic (PPL) or Candidacylindracealipase (CCL).