The sulfinyl moiety in Lewis base-promoted allylations
作者:J. Robin Fulton、Lamin M. Kamara、Simon C. Morton、Gareth J. Rowlands
DOI:10.1016/j.tet.2009.09.042
日期:2009.11
By employing Senanayake's oxathiazolidine-2-oxide reagent, a collection of sulfinamides was prepared and provided the first examples of sulfinamides promoting the allylation of benzaldehyde and N-benzoylhydrazones with allyltrichlorosilane. The optimum sulfinamide-derived Lewis base promoter displays comparable activity to the best sulfinyl-based Lewis bases reported. The use of bis-sulfoxides is also discussed. (C) 2009 Elsevier Ltd. All rights reserved.
Indium-Mediated Asymmetric Allylation of Acylhydrazones Using a Chiral Urea Catalyst
作者:Kian L. Tan、Eric N. Jacobsen
DOI:10.1002/anie.200603354
日期:2007.2.12
Asymmetric allylation of N-benzoylhydrazones promoted by novel C2-symmetric bis-sulfoxide organocatalysts
作者:Fred García-Flores、Luz S. Flores-Michel、Eusebio Juaristi
DOI:10.1016/j.tetlet.2006.09.113
日期:2006.11
Novel C-2-symmetric bis-sulfoxide/N-oxide (R,R)-5 was prepared in good yield according to the Andersen protocol with (S)-menthyl p-tolyl sulfinate (2 equiv) and the dilithium derivate of 2,6-dimethylpyridine N-oxide. Reduction of (R,R)-5 to pyridine/ bis-sulfoxide (R,R)-6 was accomplished by means of Katritzky's procedure (Fe-0/AcOH). Both bis-sulfoxides (R,R)-5 and (R,R)-6 are efficient chiral organocatalysts in the asymmetric allylation of N-benzoyl hydrazones derived from both aldehydes and ketones. (c) 2006 Elsevier Ltd. All rights reserved.
Indium-Mediated Catalytic Enantioselective Allylation of <i>N</i>-Benzoylhydrazones Using a Protonated Chiral Amine
作者:Sung Jun Kim、Doo Ok Jang
DOI:10.1021/ja1035336
日期:2010.9.8
A catalytic enantioselective indium-mediatedallylation of N-benzoylhydrazones in conjunction with a protonated chiral amine affording enantioenriched homoallylic amines with an extremely high level of enantioselectivity and chemical yield was developed.
Sulfoxides were first introduced to the allylation of N-acylhydrazones with allyltrichlorosilanes as effective neutral coordinate-organocatalysts (NCOs). Both high diastereo- and enantioselectivity were attained when optically active chiral sulfoxides were used. Asymmetric crotylations using (Z)- and (E)-crotyltrichlorosilanes showed a high level of stereospecificity (Z --> anti and E --> syn) with
亚砜首先被引入到 N-酰基腙与烯丙基三氯硅烷的烯丙基化反应中,作为有效的中性配位有机催化剂 (NCO)。当使用旋光手性亚砜时,可以获得高的非对映选择性和对映选择性。使用 (Z)- 和 (E)-巴豆基三氯硅烷的不对称巴豆化显示出高水平的立体特异性(Z --> anti 和 E --> syn),具有高对映选择性。