A decarboxylative cross-coupling reaction of α-aminoacids with nitrones via visible-light-induced photoredox catalysis has been established for easy access to β-amino hydroxylamines and vicinal diamines with structural diversity, which is featured with simple operation, mild conditions, readily available α-aminoacids, and a broad scope of nitrone substrates. The application of this protocol can furnish
Samarium Diiodide-Induced Asymmetric Synthesis of Optically Pure Unsymmetrical Vicinal Diamines by Reductive Cross-Coupling of Nitrones with <i>N</i>-<i>tert</i>-Butanesulfinyl Imines
作者:Yu-Wu Zhong、Ming-Hua Xu、Guo-Qiang Lin
DOI:10.1021/ol048444d
日期:2004.10.1
[reaction: see text] An efficient method for the preparation of opticallypure unsymmetrical vicinal diamines by the SmI(2)-induced reductive cross-coupling of nitrones with chiral N-tert-butanesulfinyl imines was developed. This is the first successful example of the highly diastereoselective and enantioselective cross-coupling between two different imine species. It provides a straightforward access
Trimethylsilyl trifluoromethanesulfonate-promoted cycloaddition of nitrones with silyl enol ethers: synthesis and reactivity of 5-siloxyisoxazohdines
作者:Chiara Camiletti、Dilip D. Dhavale、Luca Gentiluccia、Claudio Trombini
DOI:10.1039/p19930003157
日期:——
In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf), the reaction of nitrones with silyl enolethers affords 5-siloxyisoxazolidines under mild conditions, in good to excellent yields. 5-Siloxyisoxazolidines can undergo chemoselective reductions to Manoich bases or N-hydroxy-1,3-amino alcohols, and, in the presence of TMSOTf, react with silylated carbon nucleophiles at the acetalic
[reaction: see text] The first successful catalytic oxidation procedure for the chemoselective conversion of imines to nitrones is reported. The reaction is general, high yielding, and user and environmentally friendly, and furnishes a solution to the yet unanswered issue of regioselective access to nitrones by oxidation of nitrogen derivatives.
Asymmetric 1,3-Dipolar Cycloaddition Reaction of Nitrones and Acrolein with a Bis-Titanium Catalyst as Chiral Lewis Acid
作者:Taichi Kano、Takuya Hashimoto、Keiji Maruoka
DOI:10.1021/ja0523284
日期:2005.8.1
A mu-oxo-type chiral bis-Ti(IV) oxide (S,S)-1 can be successfully utilized in the asymmetric 1,3-dipolar cycloaddition reactions between various nitrones 2 and acrolein to give the corresponding isoxazolidines with high to excellent enantioselectivities. For instance, the reaction between nitrone 2 (R = t-Bu) and acrolein in the presence of 10 mol % of bis-Ti(IV) catalyst (S,S)-1 in dichloromethane at -40 degrees C gave the corresponding endo cycloadduct with 97% ee.