Geometry Driven Intramolecular Oxidative Cyclization of Enamides: An Umpolung Annulation of Primary Benzamides with Acrylates for the Synthesis of 3-Methyleneisoindolin-1-ones
作者:Joydev K. Laha、Mandeep Kaur Hunjan、Rohan A. Bhimpuria、Deepika Kathuria、Prasad V. Bharatam
DOI:10.1021/acs.joc.7b00966
日期:2017.7.21
A palladium-catalyzed tandem oxidativeannulation of primary benzamides with acrylates via intermolecular N-alkenylation followed by intramolecular C-alkenylation yielded a stereoselective synthesis of (E)-3-methyleneisoindolin-1-ones. The study unveils, for the first time, that only E-enamides could undergo intramolecular oxidative cyclization under the optimized conditions to give isoindolinones
Metal-Free Stereoselective Synthesis of (<i>E</i>)- and (<i>Z</i>)-N-Monosubstituted β-Aminoacrylates via Condensation Reactions of Carbamates
作者:Scott R. Pollack、Amélie Dion
DOI:10.1021/acs.joc.1c01212
日期:2021.9.3
acids and pharmaceuticals. Two efficient, stereoselective methods of preparation, via acid- or base-promoted condensation reactions of carbamates, are described. The base-promoted reaction is E-selective, while acid catalysis can, through the choice of solvent, selectively form E or Z. The acid-catalyzed E-selective process proceeds through a crystallization obviating the need for chromatographic purification
Synthesis of Linear Enamides and Enecarbamates
<i>via</i>
Photoredox Acceptorless Dehydrogenation
作者:Ritu、Daniel Kolb、Nidhi Jain、Burkhard König
DOI:10.1002/adsc.202201259
日期:2023.2.21
decatungstate (TBADT) as hydrogen atom transfer (HAT) agent and a cobaloxime co-catalyst for dihydrogen evolution for the dehydrogenative preparation of linear enamides and enecarbamates from saturated precursors. The substrate scope includes several natural products and drug derivatives. The reaction does not require noble metal catalysts, exhibits short reaction times compared to previous methods and is suitable
α,β-Dehydrogenation of esters with free O H and N H functionalities via allyl-palladium catalysis
作者:Suzanne M. Szewczyk、Yizhou Zhao、Holt A. Sakai、Pascal Dube、Timothy R. Newhouse
DOI:10.1016/j.tet.2018.02.028
日期:2018.6
A direct and selective method for the alpha,beta-dehydrogenation of esters using palladium catalysis in the presence of free O-H and N-H functionalities is reported herein. Allyl-palladium catalysis allows for preservation of readily oxidizable functionalities such as amines and alcohols. Furthermore, an economical protocol using LDA was developed for the dehydrogenation of beta-amino esters. (C) 2018 Elsevier Ltd. All rights reserved.