Article
Chemistry, Organic
Julien Braire, Aurelie Mace, Rania Zaier, Marie Cordier, Joelle Vidal, Claudia Lalli, Arnaud Martel, Francois Carreaux
Summary: An improvement in the catalytic enantioselective allylboration of isatins with 2-allyl-1,3,2-dioxaborolane in the presence of chiral BINOL derivatives is reported, offering an efficient one-step access to enantioenriched N-unprotected 3-allyl-3-hydroxy-2-oxindoles. The origins of the high enantioselectivity and the key role of the alcohol additive have been investigated.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Julien Braire, Aurelie Mace, Rania Zaier, Marie Cordier, Joelle Vidal, Claudia Lalli, Arnaud Martel, Francois Carreaux
Summary: An improvement in the catalytic enantioselective allylboration of isatins with 2-allyl-1,3,2-dioxaborolane in the presence of chiral BINOL derivatives is reported. The high enantioselectivity of this reaction is due to the internal hydrogen bonding and the addition of alcohol additive, as shown by DFT calculations and kinetics study.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Aleksandra Buchcic-Szychowska, Justyna Adamczyk, Lena Marciniak, Adam Marek Pieczonka, Anna Zawisza, Stanislaw Lesniak, Michal Rachwalski
Summary: During the implementation of current research, a set of optically pure chiral aziridines and aziridine imines bearing a phosphine moiety was prepared with high chemical yield. These chiral heteroorganic derivatives were tested for catalytic utility in two asymmetric reactions, showing good catalytic activity and high enantiomeric excess.
Article
Chemistry, Organic
Romain J. Lepage, Peter W. Moore, Russell J. Hewitt, Paul H. Teesdale-Spittle, Elizabeth H. Krenske, Joanne E. Harvey
Summary: In the presence of a nucleophilic base, D-glycals-derived ring-fused gem-dibromocyclopropanes undergo ring opening to yield E-bromomethylene glycosides. The reaction mechanism involves alkoxide-induced HBr elimination, zwitterionic intermediate formation, nucleophilic addition, and protonation to give the bromoalkene product. Isotope labeling studies demonstrate the role of alcohol solvent and alcohol molecule in the reaction. The obtained mechanistic knowledge sheds light on the unique chemistry of this system and its potential applications.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Saroj Kumar Kushvaha, Maria Francis, Jayasree Kumar, Ekta Nag, Prathap Ravichandran, Sudipta Roy, Kartik Chandra Mondal
Summary: A robust tetrameric nickel complex with potential catalytic activity was successfully synthesized. The complex exhibited good selectivity and yield in the cyclopropanation reaction of heterocyclic aromatics, and the impact of ligand fields on its stability was thoroughly investigated. Solution dynamics and oligomerization of the molecules were revealed, shedding light on the mechanism of the catalytic cycle.
Article
Chemistry, Organic
Nhan N. H. Ton, Binh Khanh Mai, Thanh Vinh Nguyen
Summary: Hydroboration reaction of alkynes is an efficient tool for accessing organoboron compounds, and a novel method using tropylium salts as catalysts has been reported for metal-free hydroboration. This method allows easy access to a wide range of vinylboranes. Experimental studies and DFT calculations revealed an uncommon mechanistic pathway triggered by the hydride abstraction of pinacolborane with tropylium ion.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Zhenzhong Li, Lorenz Roesler, Till Wissel, Hergen Breitzke, Torsten Gutmann, Gerd Buntkowsky
Summary: A novel immobilized chiral dirhodium catalyst has been prepared and shows high catalytic activity and significant enantioselectivity in asymmetric cyclopmpanation reaction. The catalyst can be readily recovered and reused.
JOURNAL OF CO2 UTILIZATION
(2021)
Article
Chemistry, Organic
Naoki Sakai, Kohei Ojima, Seiji Mori, Takeshi Oriyama
Summary: In this study, a novel chiral catalyst derived from (S)-proline was used to perform enantioselective kinetic resolution of beta-unfunctionalized primary alcohols with benzoyl chloride. Valuable chiral 2-substituted propan-1-ols were obtained with good enantioselectivities, and density functional theory calculations revealed the crucial role of noncovalent interactions, such as CH-pi interactions, in the enantioselectivity of the resolution.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Engineering, Environmental
Tobias Prucker, Aliena Lamberty, Johannes Thiessen, Matthias Konig, Andreas Jess
Summary: This study investigates the reaction of medium chain length paraffins to linear monoolefins and reveals that n-octenes are rapidly converted to n-octadienes, which further transform into C8-aromatics. A kinetic model accurately predicts the product formation in the absence of deactivation.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Kaixiang Xu, Shan Mu, Huijuanzi Rao, Jialei Hu, Hanfeng Ding
Summary: The asymmetric total syntheses of (+)-vulgarisins A-E, which share a rare and highly oxygenated [5-6-4-5] tetracyclic core structure that were isolated from P. vulgaris Linn., have been described for the first time in a divergent manner. Key transformations include: 1) a catalytic asymmetric intramolecular cyclopropanation to forge the A ring bearing desired stereochemistry at C14; 2) a one-pot borylation/conjugate addition process for creation of the C1-C11 bond; 3) a Wolff ring contraction to assemble the bicyclo[3.2.0]heptane subunit (CD rings); and 4) a stereocontrolled pinacol cyclization for construction of the central B ring of the natural products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Yuqi Zhu, Ting Zhou, Hong Zhang, Jieyin He, Hongguang Li, Ming Lang, Jian Wang, Shiyong Peng
Summary: This study reports a Rh(II)-catalyzed reaction method for the synthesis of α-aryl-β-aminocyclopropane carboxylic acid derivatives with stereo-isomeric centers using donor-acceptor carbenes derived from a-aryldiazoesters and vinylsulfonamides.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Mikus Purins, Jerome Waser
Summary: The paper explores the enantioselective diversification of a single starting material by extending the concept of catalytically formed chiral auxiliary from hydrogenation to cyclopropanation and epoxidation reactions. This approach eliminates the need for different chiral catalysts in alkene functionalization and allows for the control of stereochemistry using a catalytically constructed chiral auxiliary.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Georgina Kirby, Guillaume Prestat, Farouk Berhal
Summary: Herein, an atom-economical intermolecular iron-catalyzed oxyamination of alkenes is reported. The insertion of oxygenated and nitrogenated moieties from the hydroxylamine substrate was observed with full regio- and chemo-selectivity for terminal alkenes in good yields. HFIP solvent appeared to synergistically promote the formation of the oxyaminated products with the iron catalyst. Preliminary mechanistic studies suggest a pathway involving aziridination followed by in situ ring opening.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Tian-Yi Wang, Xiao-Xuan Chen, Dong-Xing Zhu, Lung Wa Chung, Ming-Hua Xu
Summary: A highly selective C(sp(2))-H functionalization reaction catalyzed by rhodium(I)-diene has been developed, enabling the synthesis of α,β-unsaturated esters containing heteroatoms under mild reaction conditions. Mechanistic studies show that the substrate affects the reaction rate and selectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Cidan Lv, Xiangxiang Meng, Min Wang, Yan Zhang, Changwei Hu, Chan Kyung Kim, Zhishan Su
Summary: The mechanism and stereoselectivity of an asymmetric cyclopropanation reaction between 3-alkenyl-oxindole and sulfoxonium ylide catalyzed by a chiral N,N'-dioxide-Mg(II) complex were explored. The presence of N-protecting groups in the isatin enhanced the reactivity of the reactants, while steric effects of substituents in the chiral ligand played a crucial role in the selectivity of the reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
