Article
Chemistry, Applied
Eugenia Marques-Lopez, Isaac G. Sonsona, Miryam Garces-Marin, M. Concepcion Gimeno, Raquel P. Herrera
Summary: In this study, the potential of phosphites as nucleophiles for the asymmetric synthesis of chiral chromene derivatives was explored. By employing asymmetric organocatalyzed phospha-Michael addition, chiral chromenylphosphonates were synthesized using a bifunctional squaramide. The optimized protocol provided good reactivity with yields of up to 95% and chiral products with an enantiomeric excess of up to 98%.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Marko Nesic, David B. Ryffel, Jonathan Maturano, Michael Shevlin, Scott R. Pollack, Donald R. Gauthier Jr, Pablo Trigo-Mourin, Li-Kang Zhang, Danielle M. Schultz, Jamie M. McCabe Dunn, Louis-Charles Campeau, Niki R. Patel, David A. Petrone, David Sarlah
Summary: The collaborative total synthesis of darobactin A, a selective antibiotic against Gram-negative bacteria, has been achieved in a convergent manner using D-Garner's aldehyde and L-serine as starting materials. The synthesis involved 16 steps and three scalable routes were developed to synthesize non-canonical amino acids. The closure of the bismacrocycle was successfully achieved through sequential, halogen-selective Larock indole syntheses, with the cyclization order playing a crucial role in the formation of the desired atropisomer.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Hengqian Song, Jiacheng Song, Lihong Yan, Weigang He, Pengyan Wang, Yuanzhen Xu, Hongbo Wei, Weiqing Xie
Summary: The asymmetric synthesis of (-)-dihydrospirotryprostatin B has been achieved in 8 longest linear steps from commercially available amino acids. The key step involves the tandem Michael addition of oxindole derived from dipeptide diketopiperazine to alkynone, leading to the rapid construction of the spiro [pyrrolidine-3,3'-oxindole] scaffold.
TETRAHEDRON LETTERS
(2021)
Article
Biochemistry & Molecular Biology
Luka Baresic, Davor Margetic, Zoran Glasovac
Summary: The reaction of furfuryl guanidines with dienophiles showed a strong reaction dependence on the nucleophilicity of the counterion and the structure of guanidine, allowing for control over the selectivity of the reaction products.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Physical
Alexey A. Tsygankov, Denis Chusov
Summary: By using a fluoride anion source, well-known transition metal catalysts can be transformed into high-performance versions, increasing catalytic activity, particularly in reactions such as asymmetric cyanation of aldehydes, asymmetric Michael addition, and synthesis of cyclic carbonates.
Article
Chemistry, Multidisciplinary
Karem J. Sabah, N. Idayu Zahid, Rauzah Hashim
Summary: A series of new mix aza- and thia-macrocyclic glycolipids have been synthesized and studied for their enantiomeric selectivity, with the galactose aza-crown ether-based glycolipid 21 proving to be the most effective catalyst with 90% ee in the enantioselective Michael addition reaction.
RESEARCH ON CHEMICAL INTERMEDIATES
(2021)
Article
Chemistry, Multidisciplinary
Karin Ratzenboeck, Mir Mehraj Ud Din, Susanne M. Fischer, Ema Zagar, David Pahovnik, A. Daniel Boese, Daniel Rettenwander, Christian Slugovc
Summary: Using water as a monomer in polymerization reactions is a sustainable strategy. The oxa-Michael polyaddition of water and divinyl sulfone demonstrates high yield polymerization in an interfacial reaction under nucleophilic or base catalysis at room temperature. The resulting polyethersulfone is then applied as a solid polymer electrolyte, showing excellent oxidative stability and conductivity.
Article
Chemistry, Multidisciplinary
Zubeda Begum, Haruka Sannabe, Chigusa Seki, Yuko Okuyama, Eunsang Kwon, Koji Uwai, Michio Tokiwa, Suguru Tokiwa, Mitsuhiro Takeshita, Hiroto Nakano
Summary: Simple primary beta-amino alcohols act as efficient organocatalysts in the asymmetric Michael addition of beta-keto esters with nitroalkenes, producing highly pure chiral Michael adducts. The choice of catalyst and reaction temperature determines the enantiomeric outcome of the adducts.
Article
Chemistry, Physical
Yongkang Song, Jian Wang, Shaomin Deng, Guohua Liu, Tanyu Cheng
Summary: Domino catalytic reactions are a powerful strategy for synthesizing complex and high-value compounds. In this study, a domino enantioselective Michael addition/cyclization process, catalyzed by inexpensive and readily available quinidine, was developed. The reaction proceeded smoothly under mild conditions at room temperature within 2 hours, affording chiral 1,4-dihydro-pyridine containing benzosultams in good yields (up to 95%) and excellent enantioselectivities (up to 99% ee).
MOLECULAR CATALYSIS
(2022)
Article
Chemistry, Applied
Irma Garcia-Monzon, Jorge Borges-Gonzalez, Tomas Martin
Summary: The heterogenization of homogeneous catalysts onto a solid support is a crucial step towards sustainable chemistry. In this study, we developed a series of polymer-supported tetrahydropyran-based hybrid dipeptides as active catalysts for the enantioselective Michael addition of aldehydes to beta-nitrostyrenes. The optimal anchor position and orientation between the catalyst and solid support, as well as the linker length, were carefully designed to enhance the catalytic efficiency. These supported catalysts exhibited high yields and enantiomeric excesses, and detailed deactivation studies provided important insights for prolonging their useful life.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Mingkang Zhou, Yaodong Lin, Xiao-Xuan Chen, Guangqing Xu, Lung Wa Chung, Wenjun Tang
Summary: We report the chiral diboron-templated asymmetric homocoupling of aryl alkyl ketimines, leading to the formation of chiral vicinal tetrasubstituted diamines with high enantioselectivities and good to high yields. This powerful and efficient reaction is achieved by rational design and engineering of chiral diborons, which participate in a [3,3]-sigmatropic rearrangement. DFT studies reveal that different conformational assembling strategies of chiral diborons ensure the excellent enantioselectivity in the tight concerted transition states.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Ruslan A. Kovalevsky, Maxim Smirnov, Alexander S. Kucherenko, Kseniya A. Bykova, Elizaveta Shikina, Sergei G. Zlotin
Summary: In this study, 2-nitroallylic carbonates were used for the first time as promising biselectrophilic C3 synthons. They reacted with kojic acid derivatives in a bifunctional squaramide catalyzed asymmetric domino reaction, yielding nitro compounds that contain two hydroxypyranone units. The reaction products undergo noncatalytic epimerization at the carbon atom next to the nitro group. A plausible mechanism of the epimerization based on reversible formation of intermediate aci-nitro compound is proposed. The double addition products were transformed into configurationally stable acetates and chiral nitro glutarates, which are promising precursors for chiral amino glutaric acid derivatives.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Yiqi Ren, Maodi Wang, Qihua Yang, Junfa Zhu
Summary: The development of chiral solid catalysts using unconventional strategies is crucial for efficient heterogeneous asymmetric catalysis. The study presents a chiral solid catalyst, chiral diamine modified Ni/SiO2, for asymmetric Michael addition. The experimental results demonstrate that the peripheral Ni sites in close contact with SiO2 support are likely to be the active sites.
Article
Chemistry, Multidisciplinary
Sebastian Frankowski, Justyna Kowalska, Anna Albrecht
Summary: A novel method has been described for the preparation of enantiomerically enriched pyridine derivatives using 2-pyridylacetic acids as valuable synthons in an asymmetric fashion. The synthesis based on iminium activation using a chiral aminocatalyst successfully controlled the stereochemical outcome of the transformation.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Organic
Prasenjit Gayen, Prasanta Ghorai
Summary: A highly chemoselective 1,2-addition of thiols with 2-isothiocyanatochalcones followed by an enantioselective intramolecular thia-Michael addition cascade has been developed for the synthesis of enantioenriched [1,3]-benzothiazine derivatives. The squaramide catalyst derived from cinchona provides excellent yield and enantioselectivity with a wide range of substrates. Furthermore, this strategy can be extended to access enantioenriched organophosphorus-substituted [1,3]-benzothazines using diphenylphosphine oxide nucleophile.
Article
Chemistry, Analytical
Yuanli Long, Shuang Liu, Yunfei Cai, Jiale Zhang, Xinfeng Zhang, Yurong Tang
Article
Chemistry, Multidisciplinary
Qian Yang, Guanglong Pan, Jie Wei, Wentao Wang, Yurong Tang, Yunfei Cai
Summary: By modifying the structure of carbon nitride, a heterogeneous photocatalytic system for both decarboxylative addition and reductive dimerization has been developed with remarkable catalytic activity. The system offers advantages such as lower catalyst loading, enhanced optical absorption, improved electron-hole separation, good recyclability, broad substrate scope, and easy scale-up in continuous flow for valued target synthesis.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Article
Chemistry, Organic
Guanglong Pan, Qian Yang, Wentao Wang, Yurong Tang, Yunfei Cai
Summary: A visible light-mediated heterogeneous photocatalytic cyanomethylarylation of alkenes with acetonitrile was established using CN-K as a recyclable semiconductor photocatalyst. This method allows for the efficient construction of a wide array of nitrogenous heterocyclic compounds with structural diversity, including indolines, oxindoles, isoquinolinones, and isoquinolinediones, by employing NHPI ester as a radical initiator.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Lei Xu, Sishi Zhong, Qian Yang, Jie Wei, Jiaming Zou, Hongxiang Li, Yunfei Cai
Summary: This study developed a new asymmetric radical-mediated Piancatelli-type rearrangement reaction, which allows for a three-component reaction of diverse carbon-centered radical precursors and anilines with high yields, enantioselectivities, and diastereoselectivities. The synthesized products can be applied for late-stage functionalization of valuable drug targets or natural products. The diastereoselectivity of the rearrangement reaction is controlled by Dy(III)-accelerated Z/E isomerization of Piancatelli intermediates, and the chiral Bronsted acid-catalyzed 4π-electrocyclization of pentadienyl carbocation intermediates is a key step determining both reaction rate and enantioselectivity.
Article
Chemistry, Organic
Lei Xu, Hongxiang Li, Liuzhuang Xing, Qian Yang, Yurong Tang, Yunfei Cai
Summary: A novel aza-Piancatelli rearrangement triggered cascade reaction was developed, allowing for rapid construction of diverse cyclopenta[b]pyrrolidinone derivatives. The unprecedented and highly efficient bicyclic gamma-lactam product formation is originated from an unusual retro-aza-Piancatelli rearrangement of the major cis-fused multifunctionalized cyclopentenone to the minor trans-fused one followed by a lactamization reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Review
Chemistry, Organic
Sishi Zhong, Lei Xu, Yunfei Cai
Summary: The Piancatelli reaction is a significant organic synthesis reaction, which can construct diversified functionalized cyclopentenones and polycyclic cyclopentanones. In addition, there have been developments in chiral catalytic reactions in this field.
SYNTHESIS-STUTTGART
(2022)
Article
Chemistry, Organic
Hongxiang Li, Qian Yang, Lei Xu, Jie Wei, Yurong Tang, Yunfei Cai
Summary: In this study, an asymmetric three-component rearrangement of alkenylfurans with various sulfonyl chlorides and anilines was developed via copper(I) and chiral vanadium cooperative catalysis, providing a facile access to a broad spectrum of sulfonylfunctionalized 4-aminocyclopentenones in high yields with excellent enantio- and diastereoselectivities.
Article
Chemistry, Organic
Jiaming Zou, Lei Xu, Yurong Tang, Wentao Wang, Yunfei Cai
Summary: The asymmetric synthesis of bridged tetrahydrobenzo[b]azepine and oxepine derivatives has been achieved through chiral Bri nsted acid catalyzed asymmetric aza-Piancatelli rearrangement/Michael addition sequence. The reaction proceeds under mild reaction conditions to afford the final bridged cyclic products in good yields with excellent enantio- and diastereoselectivities.
Article
Chemistry, Organic
Jie Wei, Yurong Tang, Qian Yang, Hongxiang Li, Dongxian He, Yunfei Cai
Summary: An enantioselective three-component rearrangement of alkenylfurans has been developed by merging photoredox catalysis with chiral Brønsted acid catalysis. This protocol provides expedient access to a broad spectrum of ketoalkyl-functionalized 4-aminocyclopentenones in high yields with excellent enantio- and diastereoselectivities. Diverse functional groups can be introduced via facile product derivations.
Article
Chemistry, Organic
Xiao Dan, Qian Yang, Liuzhuang Xing, Yurong Tang, Wentao Wang, Yunfei Cai
Summary: A fully heterogeneous metallaphotocatalytic C-C cross-coupling of aryl/vinyl halides with alkyl/allyl trifluoroborates has been developed using an integrated bipyridyl-Ni-(II)-carbon nitride as a stable and recyclable bifunctional catalyst. This visible-light-mediated heterogeneous protocol enables the sustainable synthesis of diverse valuable diarylmethanes and allylarenes in high efficiency.
Article
Multidisciplinary Sciences
Liuzhuang Xing, Qian Yang, Chen Zhu, Yilian Bai, Yurong Tang, Magnus Rueping, Yunfei Cai
Summary: In this study, the authors successfully incorporated privileged homogeneous bipyridyl-based Ni-catalysts into highly ordered and crystalline potassium poly(heptazine imide) (K-PHI), achieving the development goal of heterogeneous metallaphotocatalysis. The LnNi-PHI catalysts exhibit superior chemical stability and recyclability in C-P, C-S, C-O and C-N cross-coupling reactions.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Yilian Bai, Qian Yang, Yurong Tang, Xiao Dan, Wentao Wang, Yunfei Cai
Summary: In this study, a recyclable catalyst, Cu-doped carbon nitride (Cu-CN), was developed as a Cu-photo dual catalytic system. The heterogeneous CN-Cu catalyst can be used for direct alpha-alkynylation of tertiary amines using air as an oxidant, resulting in high yields of diverse propargylamines. The endogenous proximity and synergistic effect between Cu and the photocatalytic center in CN-Cu significantly enhance the Cu-photo dual catalytic activity, improving reaction efficiency and selectivity. Remarkably, this heterogeneous catalyst exhibits high chemical stability and can be recycled at least five times without loss of activity.
Article
Chemistry, Multidisciplinary
Fan Du, Xiaojie Zhou, Yilian Bai, Qing Tang, Yunfei Cai, Yurong Tang
Summary: Three metal-containing species (Mn, Ce, Eu) were constructed in carbon nitride (CN) nanocomposites through surface modification strategy. The nanocomposites showed outstanding photo-responsive oxidase-mimicking activity and colorimetric sensing properties.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Yali He, Xiao Dan, Yurong Tang, Qian Yang, Wentao Wang, Yunfei Cai
Summary: An efficient and eco-friendly heterogeneous photocatalytic system has been developed using K-modified carbon nitride as a recyclable, nontoxic and heavy metal-free photocatalyst for fluoroalkylation-distal heteroaryl, formyl and imino migration reactions. This system utilizes air as the oxidant and RFSO2Na as the fluoroalkyl source, allowing for rapid and flexible construction of valuable fluoroalkyl functionalized compounds. The reaction process involves superoxide radicals, photogenerated electrons and holes playing important roles.
Article
Chemistry, Organic
Lei Xu, Qian Yang, Sishi Zhong, Hongxiang Li, Yurong Tang, Yunfei Cai
