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
Dual Reactivity Pattern of Allenolates “On Water”: The Chemical Basis for Efficient Allenolate-Driven Organocatalytic Systems
作者:David González-Cruz、David Tejedor、Pedro de Armas、Fernando García-Tellado
DOI:10.1002/chem.200700227
日期:2007.6.4
A study of the reactivitypattern associated with zwitterionic allenolates "on water" is reported. This study establishes the chemicalbasis for two organocatalyzed allenolate-driven reaction networks operating "on water". The first one is a chemodifferentiating three building block (ABB') three-component reaction (ABB' 3CR) manifold comprising terminal alkynoates and aldehydes. The manifold produces
SmI<sub>2</sub>-Promoted Radical Addition of Nitrones to α,β-Unsaturated Amides and Esters: Synthesis of γ-Amino Acids via a Nitrogen Equivalent to the Ketyl Radical
作者:Ditte Riber、Troels Skrydstrup
DOI:10.1021/ol027386y
日期:2003.1.1
[reaction: see text] Alkyl nitrones undergo radical addition reactions to a series of alpha,beta-unsaturated amides and esters when subjected to samarium diiodide via a nitrogen equivalent to a ketyl radical anion. This reaction conveniently provides access to a variety of functionalized gamma-amino acids. The methodology was extended to the asymmetric synthesis of 4-substituted gamma-amino acids,
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
The stereoselective direct transformation of N‐(propargylic)hydroxylamines into cis‐2‐acylaziridines was achieved by the combined use of AgBF4 and CuCl. Copper salts were found to promote the transformation of the intermediary 4‐isoxazolines into 2‐acylaziridines and both 3‐aryl‐ and 3‐alkyl‐substituted 2‐acylaziridines could be prepared by using this method. Furthermore, subsequent 1,3‐dipolar cycloaddition
通过将AgBF 4和CuCl结合使用,可以将N-(炔丙基)羟胺立体选择性直接转化为顺式-2-酰基丙啶。发现铜盐可促进中间体4-异恶唑啉向2-酰基氮丙啶的转化,并且可以使用此方法制备3-芳基和3-烷基取代的2-酰基氮丙啶。此外,随后通过立体选择性单锅法从中间体2-酰基氮丙啶与马来酰亚胺原位生成的偶氮甲胺碘化物的1,3-偶极环加成反应得到相应的2-酰基吡咯烷核苷,其中包括一个八氢吡咯并[3, 4‐ c ]吡咯骨架。