Article
Chemistry, Multidisciplinary
Chang Zhao, Cuihong Sun, Xiaoyan Li, Yanli Zeng
Summary: In this study, the mechanism of Aza-Diels-Alder reaction catalyzed by N-heterocyclic imidazole halogen bond donors was explored using density functional theory. It was found that the formation of halogen bond between the catalysts and the imine can lower the energy barrier of the reaction and facilitate electron rearrangement. The stronger electron-withdrawing ability of the group bonded to the iodine atom of catalysts, the better the catalytic activity. These findings are valuable for the development of halogen bond donor catalysts in organic reactions.
Article
Chemistry, Organic
Yanli Shi, Yaqian Shi, Shanxiao Yang, Xinhuan Chen, Yan Qiao
Summary: The detailed reaction mechanisms of aldimines with tributyltin cyanide under the catalytic influence of chiral oxazaborolidinium ion (COBI) were uncovered through density functional theory (DFT) calculations. Three potential reaction pathways were examined, and two stereoselective routes were determined for the most energetically favorable mechanism. NBO analyses of the stereoselectivity-determining transition states revealed the crucial role of hydrogen bond interactions in controlling stereoselectivity. These computed findings provide valuable insights into the detailed mechanisms and underlying origins of stereoselectivity in COBI-mediated reactions of this type.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Ramalingam Boobalan, Rong-Jie Chein
Summary: The emergence of second-generation sulfur-stabilized borenium cations by halophilic Lewis acid SnCl4 results in highly active chiral Lewis acids that are effective catalysts for [4 + 2] cycloaddition, exhibiting excellent enantioselectivity for a variety of substrates and demonstrating good catalytic efficiency.
Article
Chemistry, Multidisciplinary
Stephen M. Bierschenk, Judy Y. Pan, Nicholas S. Settineri, Ulrike Warzok, Robert G. Bergman, Kenneth N. Raymond, F. Dean Toste
Summary: A highly enantioselective aza-Darzens reaction catalyzed by an enantiopure supramolecular host has been discovered. Changes in enantioselectivity were observed by substituting the external chiral amide in the catalysts, and these changes were correlated to the flexibility of the supramolecular host scaffold as measured by guest exchange kinetics. By substituting the gallium(III)based host with one based on indium(III), the most flexible and selective catalyst was developed.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Junbao Li, Jinghui Sun, Wenzhu Ren, Jinhua Lei, Runpu Shen, Yinhua Huang
Summary: A rhodium/chiral diene catalytic system is reported for the switchable synthesis of chiral bicyclic products and acyclic products. The selectivity for the formation of bicyclic products is achieved through arylation-aldol cyclization, while the selectivity for acyclic products is achieved through hydroarylation.
Article
Chemistry, Organic
Julia O. Strelnikova, Alexander N. Koronatov, Nikolai Rostovskii, Alexander F. Khlebnikov, Olesya Khoroshilova, Mariya A. Kryukova, Mikhail S. Novikov
Summary: The domino reaction catalyzed by Rh-2(Piv)(4) leads to the formation of N-sulfonylated (Z)-2-(2-aminovinyl)imidazoles, providing a direct and flexible access to the desired compounds.
Article
Chemistry, Physical
Lei Yu, Wenhai Li, Anyawan Tapdara, Sara Helen Kyne, Mandeep Harode, Rasool Babaahmadi, Alireza Ariafard, Philip Wai Hong Chan
Summary: An efficient chiral gold(I) complex-catalyzed synthetic method for the regio- and enantioselective nitroso-Diels-Alder (NDA) reaction of 1,6-diyne esters with nitrosobenzenes is described. The reaction provides access to a wide range of 3,5,6,8a-tetrahydro-1H-benzo[c][1,2]oxazines as a single regioisomer with high yields and enantiomeric excess values.
Article
Multidisciplinary Sciences
Jie Han, Siyuan Liu, Huanan Wang, Jie Wang, Hui Qian, Zhiming Li, Shengming Ma, Junliang Zhang
Summary: The 13-H elimination is a crucial step in the carbon-palladium bond quenching for the Heck reaction and has been a challenge to control enantioselectivity. Here, we developed a concise and efficient method to construct chiral allenes from fully substituted enol triflates through enantioselective 13-H elimination of alkenyl palladium species under mild conditions. The identified Xu-Phos catalysts play a crucial role in chemoselectivity and enantioselectivity. Multiple linear regression analysis shows the significance of steric effect on enantioselectivity. DFT calculations propose an intramolecular base-assisted deprotonation mechanism for this progress, and energy decomposition analysis suggests that the difference in electrostatic energy of the transition states dominates the stereoselectivity.
Article
Chemistry, Organic
Qi Xiong, Lu Xiao, Xiu-Qin Dong, Chun-Jiang Wang
Summary: In this study, an iridium-catalyzed cascade allylation/macrolactonization reaction was developed, which efficiently synthesizes chiral macrodiolides with excellent diastereoselectivities and enantioselectivities. This method is characterized by readily available substrates, high stereoselective control, and efficient synthetic steps.
Article
Chemistry, Organic
Adrian Lopez-Frances, Xabier del Corte, Zurine Serna-Burgos, Jesus M. de los Santos, Abel de Cozar, Javier Vicario
Summary: This study reports on the bispericyclic dimerization of cyclic molecules, where the behavior of the molecule as either diene or dienophile is determined by its location at the transition state. Additionally, a strong chiral self-recognition phenomenon is observed, and the study provides insight into the mechanism behind the high stereospecificity of the reaction through extensive DFT analysis.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Luo-Yu Wang, Jiapei Miao, Yu Zhao, Bin-Miao Yang
Summary: We developed a highly selective method for synthesizing 1,1'-biheteroaryls bearing a chiral N-N axis. By using chiral phosphoric acid and InBr3 as cooperative catalysts, 2,3-diketoesters reacted with 1,3-dione-derived enamines to construct 1,1'-pyrrole-indoles with high enantioselectivity, up to 92% yield, and up to 94% enantiomeric excess (ee), or bisindoles with up to 92% ee. Derivatizations of these compounds resulted in diverse functionalized N-N linked axially chiral biheteroaryls.
Article
Chemistry, Organic
Changkai Wang, Jiangtao Sun
Summary: An efficient method for the synthesis of bipyrroles with an axially chiral N-N bond has been developed using a rhodium-catalyzed C-H bond insertion reaction. The desired atropisomers were obtained in high yields (up to 97%) and with excellent enantioselectivities (up to 99% ee).
Article
Chemistry, Organic
Jonathan P. Knowles, Hannah G. Steeds, Maria Schwarz, Francesca Latter, Kevin Booker-Milburn
Summary: This method transforms simple starting materials into complex tetracyclic products with potential medicinal chemistry applications through a sophisticated chemical catalysis process.
Review
Chemistry, Multidisciplinary
Osamu Kitagawa
Summary: Biaryl atropisomers, as key structural components in various compounds, have been recently studied for their catalytic asymmetric syntheses and applications in asymmetric reactions. Previously overlooked, these compounds have now become a popular research area in synthetic organic chemistry, with successful applications in various synthetic reactions.
ACCOUNTS OF CHEMICAL RESEARCH
(2021)
Article
Chemistry, Organic
Pengfei Jia, Zhiqian Lin, Shenmeng Yan, Jiao Liang, Cankun Luo, Ruizhi Lai, Li Hai, Zhongzhen Yang, Yong Wu
Summary: This study reports a new synthetic method for the one-step synthesis of Oxo-bridged dibenzoazocines via ruthenium-catalyzed [4 + 3]-cycloannulation of aza-ortho-quinone methides with carbonyl ylides at room temperature. The method exhibits exclusive diastereoselectivity, excellent yield, mild reaction conditions, and broad substrate scope. The product can be prepared on a gram scale and further functionalized into diverse substituted dihydroisobenzofuran derivatives and a dibenzoazocine scaffold.
