Review
Chemistry, Multidisciplinary
Yong Xia, Xiaohua Liu, Xiaoming Feng
Summary: The donor-acceptor (D-A) cyclopropanes, due to the synergistic push-pull effect of vicinal electron-donating and electron-withdrawing groups, are recognized as powerful building blocks for generating polyfunctional reactive intermediates. Enantioselective reactions of D-A cyclopropanes provide an efficient approach to enantioenriched acyclic and cyclic compounds. Chiral Lewis/Bronsted acids, transition metals, and organocatalysts have been designed for such transformations, including ring-openings, annulations, and rearrangements.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Murugesan Thangamani, Kannupal Srinivasan
Summary: This method utilizes aroyl-substituted donor-acceptor (D-A) cyclopropanes and 1-naphthylamines as substrates, leading to the synthesis of dibenzo[c,h]acridines through nucleophilic ring-opening and subsequent fragmentation and cyclization reactions with reasonable substrate scope and 50-70% yields.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Yoko Hasegawa, Thomas Cantin, Jonathan Decaens, Samuel Couve-Bonnaire, Andre B. Charette, Thomas Poisson, Philippe Jubault
Summary: This article describes the diastereo- and enantioselective cyclopropanation reactions of electron-deficient allenes with donor-acceptor and diacceptor diazo reagents, leading to enantioenriched alkylidenecyclopropanes (ACPs) with high yields and selectivities. The methodology provides a direct access to ACPs bearing multiple electron-deficient substituents, expanding the availability of ACPs chemistry.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Review
Chemistry, Organic
Ani Deepthi, C. B. C. Meenakshy, Maneesh Mohan
Summary: This review discusses the use of donor-acceptor cyclopropanes (DACs) for building heterocycles. The generation of heterocycles from DACs can be achieved through (3+2), (3+3), and (4+3) cycloaddition pathways, as well as nucleophilic ring-opening reactions, intramolecular transformations, and cycloisomerizations with suitable catalysts. The mild reaction conditions and the wide range of starting materials make the DAC route attractive for heterocycle synthesis. The literature covered in this review spans from 2018 to 2023.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Multidisciplinary
Daniil A. Knyazev, Maria A. Belaya, Alexander D. Volodin, Alexander A. Korlyukov, Roman A. Novikov, Yury V. Tomilov
Summary: 'Double' donor-acceptor cyclopropanes containing a p-or m-phenylene moiety react with alkenes or dienes in the presence of GaCl3, forming gallium 1,2-zwitterionic intermediates, and the structure of the final products depends on the substrate. Unlike the para-or meta-isomers, the reaction of 2,2'-(1,2-phenylene)bis(cyclopropane-1,1-dicarboxylate) does not involve alkenes and results in the formation of isomeric tricyclo[6.2.2.02,7]dodeca-2,4,6-triene-9,9,11,11-tetracarboxylate, a product of intramolecular rearrangement.
MENDELEEV COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Liangliang Yang, Jieyin He, Haiyang Wang, Wendi Xu, Xue Zhang, Ming Lang, Jian Wang, Shiyong Peng
Summary: In this study, a copper-catalyzed (5 + 3) annulation of donor-acceptor cyclopropanes with imidazolidines was reported, providing a straightforward method to access a library of saturated 1,4-diazocanes. The asymmetric synthesis of optically active saturated 1,4-diazocanes was also achieved by two strategies: chirality transfer and dynamic kinetic asymmetric transformation.
Article
Chemistry, Applied
Yan-Cheng Liou, Yi-Ru Chen, Ching-Wen Hsu, Xuan-Rui Huang, Heng-Wei Wang, Wenwei Lin
Summary: In this study, a quinine-derived thiourea catalyst was used for an enantioselective double annulation strategy, utilizing salicylaldehyde-derived azomethine ylide and alkylidene Meldrum's acid as an acceptor-donor-acceptor. The methodology showed excellent stereoselectivity and high yields, and a possible activation model involving H-bond interaction between the catalyst and the Meldrum's acid motif was proposed to explain the observed results.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Review
Chemistry, Organic
Liangliang Yang, Haiyang Wang, Ming Lang, Shiyong Peng
Summary: This short review summarizes the recent impressive developments on the high-order dipolar annulations of donor-acceptor cyclopropanes and cyclobutanes to afford medium-sized (hetero)cycles.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Physical
Ming Bao, Karlos Lopez, Raj Gurung, Hadi Arman, Michael P. Doyle
Summary: A highly enantioselective synthesis of chiral dihydro-3H-carbazole-2-carboxylate derivatives is achieved via a one-pot cascade reaction catalyzed by nickel(II) perchlorate hexahydrate and scandium(III) trifluoromethanesulfonate. The reaction proceeds under mild conditions and provides the desired products in high yields and enantioretention. Furthermore, these dihydro-3H-carbazole-2-carboxylates can be transformed into decarboxylated compounds through hydrolysis and decarboxylation under unexpectedly mild reaction conditions, giving moderate yields with high retention of enantiomeric purity.
Article
Chemistry, Multidisciplinary
Vincent Pirenne, Emma G. L. Robert, Jerome Waser
Summary: Efficient catalytic activation of donor-acceptor aminocyclopropanes lacking the commonly used diester acceptor was achieved in a (3 + 2) dearomative annulation with indoles, yielding cycloadducts in high yields and high diastereomeric ratios, leading to tricyclic indoline frameworks containing four stereogenic centers.
Article
Chemistry, Multidisciplinary
Stefano Nicolai, Jerome Waser
Summary: This study reports a Lewis acid catalyzed (4+3) annulative addition reaction for the efficient synthesis of densely substituted azepanes. The reaction achieved good yields and high diastereoselectivity under mild conditions using ytterbium triflate or copper triflate with a trisoxazoline ligand as the catalyst. The obtained cycloadducts were convenient substrates for further modifications.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Ming Bao, Karlos Lopez, Raj Gurung, Hadi Arman, Michael P. Doyle
Summary: A highly enantioselective synthesis of chiral dihydro-3H-carbazole-2-carboxylate derivatives is achieved via a one-pot cyclopentannulation-rearrangement cascade reaction. The reaction is catalyzed by nickel(II) perchlorate hexahydrate and scandium(III) trifluoromethanesulfonate, and involves the use of 3-methylindole and non-racemic donor-acceptor cyclopropanes. The resulting products show high yields and enantioretention under mild reaction conditions, and further transformation into decarboxylated compounds can be achieved with moderate yields and high enantiomeric purity.
Article
Chemistry, Multidisciplinary
Nils L. Ahlburg, Oliver Hergert, Peter G. Jones, Daniel B. Werz
Summary: A novel class of highly activated donor-acceptor cyclopropanes with a single vinylogous acceptor is presented. These moieties undergo cycloaddition reactions with various substrates to form carbo- and heterocycles. The stereochemical outcome can be controlled by the choice of catalyst. Mechanistic and kinetic experiments were conducted to explain the catalytic cycle and stereoselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
David A. McLeod, Mathias Kirk Thogersen, Casper Larsen Barlose, Mette Louise Skipper, Erlaitz Basabe Obregon, Karl Anker Jorgensen
Summary: This study presents a novel enantioselective (8+3) cycloaddition reaction using a chiral bifunctional Bronsted base catalyst. The reaction leverages an anionic activation strategy and differs from typical Lewis-acid activation protocols. Experimental and computational results support the relevance of this reaction and its potential application in organic synthesis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Xing-Yu Wang, Xiao-Bing Wang, Yin Tian, Cheng Peng, Ming-Sheng Xie, Hai-Ming Guo
Summary: A highly enantioselective dearomative [3 + 2] annulation reaction was achieved using quinolines, isoquinolines, and pyridines with donor-acceptor aminocyclopropanes. By utilizing a C-1-symmetric imidazoline-pyrroloimidazolone pyridine as the tridentate ligand and Co(OTf)2 as the Lewis acid, chiral indolizidine and benzo-fused indolizidine derivatives were obtained with good yields (up to 98%), excellent diastereoselectivities (>20:1 dr), and excellent enantioselectivities (up to 98% ee). Mechanistic experiments and DFT calculations revealed that the tridentate nitrogen ligand acted as a bifunctional chiral ligand, coordinating with the Co(II) salt and forming a H-bond to facilitate the nucleophilic attack of N-heteroaromatics and achieve high enantioselectivity.
Article
Chemistry, Organic
Honghai Zhang, Na Yang, Jing Li, Shaojie Li, Lili Xie, Saihu Liao
Summary: The introduction of sulfonyl fluoride groups can enhance the biological activity. We have developed a radical fluorosulfonylation reaction to construct chromanes with sulfonyl fluoride groups.
Article
Polymer Science
Zan Yang, Jianxu Chen, Saihu Liao
Summary: In this study, monophosphonium-doped polycyclic arenes were introduced as an organic photocatalyst, showing high efficiency and strict photocontrol in cationic polymerizations, and exhibiting excellent performance in the polymerization of vinyl ethers.
Article
Polymer Science
Guangrong Wang, Hui Shao, Jun-An Ma, Saihu Liao
Summary: Organocatalytic atom transfer radical polymerization (O-ATRP) is a powerful tool for synthesizing metal-free polymers with spatiotemporal control by light. Chalcogenide atom-doped anthracenes, such as O, S, Se, and Te, are explored as potential photocatalysts for O-ATRP. These heteroatoms have a significant effect on the photophysical and photoredox properties, leading to different performance in the O-ATRP of MMA. Selenium analogues of N-aryl phenothiazines are identified as effective photocatalysts for O-ATRP, enabling controlled radical polymerization of MMA.
MACROMOLECULAR CHEMISTRY AND PHYSICS
(2023)
Article
Polymer Science
Yu Jiang, Hui Zhu, Jianxu Chen, Saihu Liao
Summary: This article reports the successful development of a metal-free photocatalytic method for the polymerization of natural cinnamic acid-derived bisolefinic monomers. The method utilizes energy transfer catalysis and visible light activation, resulting in colorless, sustainable polymer products.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Polymer Science
Meng Li, Jun-An Ma, Saihu Liao
Summary: Inspired by controlled radical polymerization and SuFEx click chemistry, a SuFExable vinyl monomer, 4-vinylbenzenesulfonyl fluoride (VBSF), with a good balance of stability and reactivity, was introduced. VBSF can easily undergo organocatalytic atom-transfer radical polymerization under visible light, demonstrating good controls and high end-group fidelity while preserving the sulfonyl fluoride groups. Furthermore, poly(VBSF) can be efficiently modified via SuFEx reactions with various aryl silyl ethers, enabling the rapid construction of a functional polymer library in a click fashion.
Article
Polymer Science
Jianxu Chen, Junqiang Lin, Zan Yang, Yi Wu, Saihu Liao
Summary: A class of monophosphonium photocatalysts, assembled by phosphines and alkynes, were developed as efficient organic photoredox catalysts for the visible light-mediated cationic reversible addition-fragmentation chain transfer (RAFT) polymerization of vinyl ethers. These photocatalysts enable low catalyst loading (5-20 ppm) and provide metal-free and well-defined poly(vinyl ether)s with predictable molecular weight and narrow dispersity in short reaction times. Notably, these photocatalysts offer strict temporal control for regulating chain-growth by light, and also offer insight into the correlation between catalyst structure/property and catalytic performance.
Article
Polymer Science
Yu Jiang, Hui Zhu, Jianxu Chen, Qiang Ma, Saihu Liao
Summary: In this study, the activation of p-phenylenediacrylate (PDA) was achieved by introducing electron-donating alkoxy groups, leading to the successful development of the first solution [2 + 2] photopolymerization system under visible light irradiation. Variation on the alkoxy groups and the ester parts allowed the production of linear cyclobutane-containing polymer products with high molecular weight and good solubility. Additionally, temporal control and postpolymerization modification were demonstrated using thiol-ene click reaction with this [2 + 2] photopolymerization system.
Article
Chemistry, Organic
Lu Lin, Peng Wang, Tao Dong, Gavin Chit Tsui, Saihu Liao
Summary: Here, we present a transition-metal-free and visible-light-mediated radical 1-fluorosulfonyl-2-heteroarylation of alkenes, which enables the synthesis of a variety of SO2F-containing quinoxalin-2(1H)-ones, a critical structural motif widely found in biologically active molecules. Furthermore, we demonstrate the application of this method in the modification of other heterocycles and drug molecules, as well as ligation chemistry via SuFEx click reactions.
Article
Chemistry, Organic
Na Yang, Chenxi Mao, Honghai Zhang, Peng Wang, Shaojie Li, Lili Xie, Saihu Liao
Summary: Multicomponent reactions are a powerful method for synthesizing complex molecules from structurally simple starting materials. In this study, we report a novel three-component radical-polar crossover reaction involving the tandem addition of two different olefins, initiated by the selective addition of fluorosulfonyl radicals to alkyl alkenes. This tandem process provides convenient access to multiple functionalized aliphatic sulfonyl fluoride molecules, and the transformation of the products is also demonstrated.
Article
Chemistry, Multidisciplinary
Hui Zhu, Yu Jiang, Zan Yang, Xun Zhang, Saihu Liao
Summary: A confined Bronsted acid organocatalytic system is successfully developed for the stereoselective cationic polymerization of alkenyl vinyl ethers, allowing for the synthesis of functionalized isotactic polymer materials. The polymerization shows high efficiency and stereoselectivity, and further modification on the C-C double bonds can be achieved after polymerization. The study also demonstrates the synthesis of thermoplastic copolymers with tunable properties and demonstrates sequential post-polymerization modification using thiol-ene and SuFEx click reactions.
Article
Polymer Science
Zhaogang Liu, Xun Zhang, Pan Sun, Junwei Han, Saihu Liao
Summary: Harnessing the excited state acidity of aromatic alcohols is an effective approach for controlling the ring-opening polymerization of lactones using light. In this study, common organic dyes such as bromocresol green, fluorescein, and rhodamine 6G were explored as potential photoacid promotors for the ROP of lactones. These dyes showed excellent catalytic activity under visible light irradiation, leading to polyester products with predictable molecular mass and narrow dispersity.
Article
Chemistry, Organic
Ziyang Gan, Jie Zhou, Lingyun Zhu, Xinyu Chen, Qiang Ma, Jianfeng Yan, Wei Jiang, Saihu Liao, Yuanming Li
Summary: This article describes the synthesis, properties, and application of carbonyl-bridged phenanthrene, namely phenanthrenone. A novel synthetic route involving palladium-catalyzed annulation between 4,5-dibromo-9-fluorenone and internal alkynes was developed to streamline the synthesis of phenanthrenone. Phenanthrenone derivatives possess the advantages of both fluorenone and phenanthrene backbones, and can serve as an ideal electron-deficient and π-building block for developing novel polycyclic aromatic hydrocarbons. In addition, phenanthrenone derivatives can act as organic photoredox catalysts for organocatalytic atom transfer radical polymerization and oxidation of alcohol.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Honghai Zhang, Shaojie Li, Han-Liang Zheng, Gangguo Zhu, Saihu Liao, Xingliang Nie
Summary: Sulfonyl fluorides, known for their unique reactivity and stability, have gained increasing attention from medicinal chemists and chemical biologists. Researchers have developed a novel method for photocatalytic induced synthesis of alkylsulfonyl fluorides based on the SO2 radical insertion/fluorination strategy, enabling the late-stage fluorosulfonylation of natural products and drugs with primary, secondary, and tertiary aliphatic carboxylic acid NHPI esters.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Polymer Science
Qiang Ma, Yu Jiang, Junqiang Lin, Xun Zhang, Hui Shao, Saihu Liao
Summary: Orthogonal catalysis is a powerful method for the synthesis of block copolymers, allowing two different polymerization reactions to be performed simultaneously using a single catalyst.
Article
Polymer Science
Zan Yang, Wenpei Xiao, Xun Zhang, Saihu Liao
Summary: This study reports an organocatalytic degenerate chain transfer (DCT) polymerization of vinyl ethers with temporal control under visible light. By using a bisphosphonium salt as the photocatalyst and thioacetal as the chain transfer agent, poly(vinyl ether)s with good molecular weight control and narrow molecular weight distributions can be obtained. The resulting polymers show high chain-end fidelity, allowing further chain extension and functionalization to synthesize block copolymers and end-functionalized polymers. The stability and efficiency of the catalyst enable a strict temporal control over polymer chain growth at high monomer conversion for a long dark period.
