Article
Chemistry, Physical
Fangfang Guo, Jiean Chen, Yong Huang
Summary: Recently, chiral N-heterocyclic carbenes (NHCs) have been established as powerful catalysts for enantioselective bond-forming processes via noncovalent interactions. A bifunctional NHC with an embedded hydrogen-bonding motif has been reported in this study, showing remarkable tolerance of various Michael acceptors in an asymmetric aza-conjugate addition reaction, with catalytic efficiency far exceeding that of the benchmark tertiary amine-thiourea scaffold.
Article
Chemistry, Multidisciplinary
Jin Hyun Park, Sun Bu Lee, Byeong Jun Koo, Han Yong Bae
Summary: A water-accelerated, N-heterocyclic carbene (NHC)-catalyzed aza-Michael addition reaction was reported for the synthesis of beta-aminosulfonyl fluorides, key components of the SuFEx reaction. Water as a reaction medium significantly enhanced the reaction rate and demonstrated late-stage ligation with bioactive molecules.
Article
Chemistry, Organic
Amol B. Gorde, Anas Ansari, Ramesh Ramapanicker
Summary: New molecules were designed and synthesized to improve the catalytic ability of the catalyst, resulting in high catalytic activity and stereoselectivity under optimized conditions. The studies showed high yields of Michael adducts with excellent enantioselectivities and diastereoselectivities in a wide range of aldehydes and beta-nitrostyrenes.
Article
Chemistry, Multidisciplinary
Martin Berger, Davide Carboni, Paolo Melchiorre
Summary: The study presents the first catalytic enantioselective conjugate addition of allyl groups to alpha, beta-unsaturated aldehydes, utilizing the visible-light-excitation of chiral iminium ions to activate allyl silanes toward the formation of allylic radicals. This radical mechanism overcomes issues seen in traditional conjugate allylation processes and selectively installs prenyl fragments at the beta-carbon of enals.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Viktoria Kozma, Zsolt Szakonyi, Gyorgy Szollosi
Summary: This study reveals the structural effects of beta-amino acids on the asymmetric Michael additions, including the impact of substituent bulkiness on selectivity, the beneficial arrangement of functional groups in cis isomers, and the influence of nitrogen substituents on reaction rate and enantioselectivity.
Article
Chemistry, Multidisciplinary
Sebastian Mummel, Felix Lederle, Eike G. Huebner, Jan C. Namyslo, Martin Nieger, Andreas Schmidt
Summary: Sydnone methides are rare compounds that can form pi-electron rich anionic N-heterocyclic carbenes and coordinate with various metals, while also undergoing C-C coupling reactions under specific catalysts. Studies have determined their electronic properties and NMR spectra.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Chun-Lin Zhang, Yuan-Yuan Gao, Hai-Ying Wang, Bang-An Zhou, Song Ye
Summary: An NHC-catalyzed de novo synthesis method for axially chiral benzothiophene/benzofuran-fused biaryls has been reported, providing a convenient and efficient access to these compounds with high enantioselectivities. The method also works well for the synthesis of tetra-ortho-substituted biaryls, addressing an unsolved problem in the field.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Organic
Barnali Jana, Monotosh Mondal, Shibashis Halder, Atanu Mahata, Sameer Saurav, Sushovan Paladhi
Summary: This article summarizes the progress made in the past 10 years in using unprotected and protected maleimides for asymmetric organocatalytic 1,4-conjugate additions. The review provides an overview of different types of nucleophiles, catalysts, substrate scope, limitations, mechanism, and synthetic utilities for each reaction. It encourages researchers worldwide to focus on the development of new methodologies, including asymmetric photo redox catalysis, for the further functionalization of maleimides.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Carmela De Risi, Arianna Brandolese, Graziano Di Carmine, Daniele Ragno, Alessandro Massi, Olga Bortolini
Summary: Oxidative N-heterocyclic carbene (NHC) catalysis has the potential to achieve oxidative and oxygenative transformations, generating various NHC-bound intermediates and enabling non-umpolung processes through the activation of carbon atoms and heteroatoms. This review aims to discuss the recent developments in the field of oxidative NHC catalysis since 2014, with a focus on pivotal intermediates and their mechanistic involvement. More details can be found in the review article by C. De Risi and co-workers.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Review
Chemistry, Multidisciplinary
Carmela De Risi, Arianna Brandolese, Graziano Di Carmine, Daniele Ragno, Alessandro Massi, Olga Bortolini
Summary: Oxidative N-heterocyclic carbene (NHC) catalysis enables oxidative and oxygenative transformations, producing various NHC-bound intermediates and facilitating non-umpolung processes by activating carbon atoms and heteroatoms. This review discusses the developments in the literature on oxidative NHC catalysis since 2014, with a specific focus on pivotal intermediates and their mechanistic involvement.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Simiao Zhang, Xiaoxue Wang, Li-Li Han, Jibin Li, Zheng Liang, Donghui Wei, Ding Du
Summary: Atropisomers bearing multiple stereogenic axes have become increasingly important in material science, pharmaceuticals, and catalysis. However, the construction of multi-axis atropisomers with high stereoselectivity remains rare and challenging. In this study, a new class of 1,2-diaxially chiral triaryl alpha-pyranones was successfully synthesized in a single-step reaction, demonstrating broad substrate scope and excellent stereo-control. The success of this reaction can be attributed to the rational design of structurally matched reaction partners and the careful selection of the asymmetric catalytic system.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Applied
Laura A. Bryant, Kenneth Shankland, Hannah E. Straker, Callum D. Johnston, Nicholas R. Lees, Alexander J. A. Cobb
Summary: The article describes a rare organocatalytic intramolecular cyclization of resorcinols with a high enantioselectivity using a specific organocatalyst. The obtained bicyclic resorcinols show excellent utility in the synthesis of cannabinoid-like compounds, and exhibit anticonvulsant activity.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Martin Kamlar, Michal Urban, Jan Vesely
Summary: Over the past decade, the combination of organocatalysis and transition metal catalysis has become an important tool for synthesizing optically pure compounds with chiral quaternary centers, including spiro heterocyclic molecules. The dominant methods in enantioselective synthesis of spiro heterocyclic compounds involve chiral aminocatalysis, NHC catalysis, as well as non-covalent catalysis using chiral phosphoric acids, thiourea, and squaramide derivatives. This review article provides a summary of enantioselective methods for constructing spirocyclic heterocycles using a combination of organocatalysis and transition metal catalysis.
Review
Chemistry, Physical
Guangjin Zhen, Kai Jiang, Biaolin Yin
Summary: Dearomative reactions enable the concise assembly of highly functionalized three-dimensional molecules by disrupting the aromaticity of starting materials. N-heterocyclic carbenes (NHCs) have emerged as powerful catalysts for dearomatization reactions, allowing for the construction of natural product and drug skeletons. This overview summarizes the progress in NHC-catalyzed dearomative reactions, classifying the reactions by modes and categories of intermediates and providing representative mechanisms.
Article
Chemistry, Applied
Xiao Lin, Keli Ge, Ningning He, Xuling Chen, Pengfei Li, Mingxin Dong, Wenjun Li
Summary: A chiral phosphoric acid-catalyzed enantioselective aza-addition reaction of arylamines with ketimines has been developed, resulting in the construction of chiral acyclic N,N-acetal motifs. The reaction proceeds smoothly under standard conditions, yielding a series of acyclic N,N-acetals in 82-99% yield with 80-96% ee.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Physical
Fangfang Guo, Jiean Chen, Yong Huang
Summary: Recently, chiral N-heterocyclic carbenes (NHCs) have been established as powerful catalysts for enantioselective bond-forming processes via noncovalent interactions. A bifunctional NHC with an embedded hydrogen-bonding motif has been reported in this study, showing remarkable tolerance of various Michael acceptors in an asymmetric aza-conjugate addition reaction, with catalytic efficiency far exceeding that of the benchmark tertiary amine-thiourea scaffold.
Article
Chemistry, Applied
Baoli Chen, Li Li, Jiean Chen, Yong Huang
Summary: An organocatalytic protocol has been developed for the direct coupling of aliphatic aldehydes with sulfonium ylides, resulting in the formation of alpha,beta-unsaturated carbonyl compounds with a formyl substituent. The reaction demonstrates mild conditions, convergence, and control of olefin geometry.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Jingwei Xu, Zhiqi He, Jiwei Zhang, Jiean Chen, Yong Huang
Summary: C(sp(3))-C(sp(2)) cross-coupling reactions are essential tools for organic synthesis. This study reports the discovery of a designer thioether as an effective catalyst for the reaction between an allyl bromide and an arylboronic acid.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Baoli Chen, En Li, Feifei Song, Nicolas Guimond, Jiean Chen, Yong Huang
Summary: The reversible addition of benzyl alcohol onto heteroarenium salts under basic conditions was investigated. By fine-tuning the nature of the arenium and substituents, a range of pyrimidinium substrates capable of undergoing C6-selective alcohol addition was discovered. Crossover experiments were conducted to confirm the addition elimination equilibrium under basic conditions.
Article
Chemistry, Multidisciplinary
Chuan Wan, Zhanfeng Hou, Dongyan Yang, Ziyuan Zhou, Hongkun Xu, Yuena Wang, Chuan Dai, Mingchan Liang, Jun Meng, Jiean Chen, Feng Yin, Rui Wang, Zigang Li
Summary: Visible-light-mediated methods for cysteine-selective bioconjugation suffer from bio-incompatible conditions and slow kinetics. Here, we report a transition metal-free thiol-sulfoxonium ylide photo-click reaction that enables bioconjugation under bio-compatible conditions. It demonstrates high cysteine-selectivity and rapid reaction kinetics using riboflavin derivatives as photocatalysts. This method provides efficient tools for exploring the druggable content of the human proteome.
Article
Chemistry, Multidisciplinary
Ke Liao, Cho Ying Chan, Siqi Liu, Xinhao Zhang, Jiean Chen, Yong Huang
Summary: Functionalizing molecules through selective cleavage of carbon-carbon bonds is a promising approach, but the selective cleavage of inert C-sp3-C-sp3 bonds in hydrocarbon feedstocks remains challenging. This article presents a straightforward protocol for cleavage and functionalization of C(sp3)-C-sp3 bonds in alkylbenzenes using photoredox catalysis. Our method utilizes two distinct bond scission pathways depending on the nature of the benzylic substituents. This strategy provides a practical means of cleaving inert C-sp3-C-sp3 bonds in molecules without heteroatoms, generating various radical species.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
En Li, Kai Tang, Zhuhui Ren, Xiaoyun Liao, Qianchen Liu, Yong Huang, Jiean Chen
Summary: The successful enantioselective beta-alkylation of homoenolates using C-sp3 electrophiles through an S(N)2 strategy is reported. The method shows a broad scope and delivers good yields and excellent enantioselectivities (up to 99% ee). It enables the installation of drug-like structural motifs and presents a concise synthetic route to chiral pyrroloindoline-type skeletons. Preliminary mechanistic studies support a direct S(N)2 mechanism.
Article
Multidisciplinary Sciences
Zhixin Li, Yan Zhang, Qianqian Yang, Jindong Wu, Zhi Ren, Fengzhan Si, Jing Zhao, Jiean Chen
Summary: Hydrogen, with its efficient energy storage and carbon-free features, is considered a promising future energy source. The energy input required for hydrogen production is a crucial factor, and current water electrolysis methods are hindered by the high overpotential of the oxygen evolution reaction (OER). The formaldehyde oxidation reaction (FOR) provides a thermodynamically favorable alternative, and our designed catalyst efficiently produces hydrogen at an ultra-low potential and maintains long-term stability, achieving nearly 100% Faraday efficiency (FE) when combined with the cathodic hydrogen evolution reaction (HER).
Article
Chemistry, Multidisciplinary
Wangsheng Liu, Linrui Zhang, Xiaoyun Liao, Jiean Chen, Yong Huang
Summary: The NHC-catalyzed asymmetric [3+2] cyclization of benzoyl cyanides to homoenolate generated in situ from enals efficiently constructs a series of chiral cyclic compounds bearing vicinal quaternary stereocenters under mild reaction conditions. Representative large-scale and derivatization reactions of the chiral cyclic products demonstrate the potential synthetic utility of this protocol.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Chuan Wan, Yuena Wang, Chenshan Lian, Qi Chang, Yuhao An, Jiean Chen, Jinming Sun, Zhanfeng Hou, Dongyan Yang, Xiaochun Guo, Feng Yin, Rui Wang, Zigang Li
Summary: This study develops a novel visible-light-driven thioacetal activation reaction for facile modification of histidine residues. The method allows chemo-selective modification on peptides and proteins, enabling efficient histidine-proteome profiling. 78 histidine containing proteins were found for the first time, most of which function in metal accumulation in brain related diseases.
Article
Chemistry, Multidisciplinary
Delong Mu, Shuqiong Pan, Xiaoyu Wang, Xiaoyun Liao, Yong Huang, Jiean Chen
Summary: In this study, a rhodium-catalyzed desymmetrization of dihydrosilanes with heterocyclic compounds via intermolecular dehydrogenative C-H silylation was developed. The strategy demonstrated tolerance towards a variety of thianaphthene and thiophene derivatives, leading to the synthesis of a wide range of silicon-stereogenic acyclic monohydrosilanes. Additionally, rare skeletons featuring bis-silicon-stereogenic centers were designed to further enhance the diversity of the compound library. Preliminary mechanistic studies revealed the crucial role of the spatial environment surrounding the Si-center in enabling intermolecular C-H silylation preferentially.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Ke Liao, Fengjin Wu, Jiean Chen, Yong Huang
Summary: This study achieved the photoredox cleavage of hindered C-sp3-C-sp3 bonds under neutral conditions by employing a relayed proton coupled electron transfer strategy, enabling the cleavage and functionalization of highly branched alcohols.
CELL REPORTS PHYSICAL SCIENCE
(2022)
