Enantioselective Enolate Protonation in Sulfa–Michael Addition to α-Substituted <i>N</i>-Acryloyloxazolidin-2-ones with Bifunctional Organocatalyst
作者:Nirmal K. Rana、Vinod K. Singh
DOI:10.1021/ol202808n
日期:2011.12.16
Organocatalytic conjugate addition of thiols to α-substituted N-acryloyloxazolidin-2-ones followed by asymmetric protonation has been studied in the presence of cinchona alkaloid derived thioureas. Both of the enantiomers are accessible with the same level of enantioselectivity using pseudoenantiomeric quinine/quinidine derived catalysts. The addition/protonation products have been converted to useful biologically
Metal-, Photocatalyst-, and Light-Free Direct C–H Acylation and Carbamoylation of Heterocycles
作者:Matthew T. Westwood、Claire J. C. Lamb、Daniel R. Sutherland、Ai-Lan Lee
DOI:10.1021/acs.orglett.9b02679
日期:2019.9.6
Direct C-H acylations and carbamoylations of heterocycles can now be readily achieved without requiring any conventional metal, photocatalyst, electrocatalysis, or light activation, thus significantly improving on sustainability, costs, toxicity, waste, and simplicity of the operational procedure. These mild conditions are also suitable for gram-scale reactions and late-stage functionalizations of
photoinduced acylation of N‐heterocycles is explored. This visible‐lighttriggered reaction occurs not only under extremely mild reaction conditions, but also does not require the presence of a photosensitizer. The mechanistic studies suggest formation of EDA complexes prompt to harness the energy from visible‐light. Compatibility with a large panel of α‐keto acids as acyl precursors and an array of N‐heterocycles
Electrosynthesis of Stabilized Diazo Compounds from Hydrazones
作者:Nour Tanbouza、Alessia Petti、Matthew C. Leech、Laurent Caron、Jamie M. Walsh、Kevin Lam、Thierry Ollevier
DOI:10.1021/acs.orglett.2c01803
日期:2022.7.1
An electrochemical synthesis of diazocompounds from hydrazones in yields as high as 99% was performed. This method was elaborated as a useful synthetic method and demonstrated on various diazocompounds (24 examples). Apart from exhibiting an efficiency that matched that of commonly used harsh and toxic chemical oxidants, this reaction is practically simple to set up, requires mild conditions, and