作者:Evelina Colacino、Pierrick Nun、Francesco Maria Colacino、Jean Martinez、Frédéric Lamaty
DOI:10.1016/j.tet.2008.03.091
日期:2008.6
13C MAS nuclear magnetic resonance experiments. We have also studied the temperature profile during the reaction. A comparative study with the corresponding solvent-free microwave activated reaction showed the superiority of the ball-milling method; 31 examples are described, including the synthesis of the anti-aging agent C-phenyl-N-tert-butyl nitrone (PBN) and one of its analogues C-2-pyridyl-N-tert-butylnitrone
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
The scope and potential of the reaction have been investigated and developed. The reaction can also be catalyzed by secondaryamines. The use of chiral cyclic amines, such as L-proline leads to optically active beta-hydroxynitrones in moderate yield and with moderate to high enantiomeric excess. The reaction mechanism was studied by kinetic measurements, intermediate and product analysis, and determination
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。