Article
Chemistry, Multidisciplinary
Yulin Han, Anni Qin, Qian Zhang, Xue Zhang, Hui Qian, Shengming Ma
Summary: The Rh-catalyzed reaction allows for the efficient synthesis of cis-fused bicyclic products with excellent selectivity and tolerance towards synthetically useful functional groups. The proposed mechanism involves the rapid racemization of the allene moiety in the starting materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Rei Tomifuji, Shunpei Murano, Satoru Teranishi, Daiki Kuroda, Takuya Kurahashr, Seijiro Matsubara
Summary: The enantioselective oxa-Diels-Alder reaction of nonactivated substrates using FeCl3 and a 1,1'-bi-2-naphthol (BINOL) derived chiral phosphoric acid as a multiple activation catalyst was successfully achieved in this study. Various oxygen-containing six-membered heterocycles were synthesized in high yields and in an enantioselective manner. Density functional theory (DFT) calculations revealed the synergistic activation of two lone pairs of an aldehyde by both Lewis acidic and Bronsted acidic moieties in the catalyst system to facilitate enantioselective addition reaction of dienes.
Article
Chemistry, Multidisciplinary
Pallab Karjee, Manmath Mishra, Bijoy Debnath, Tharmalingam Punniyamurthy
Summary: The annulative coupling of donor-acceptor cyclopropanes with cyclic secondary amines using Ni(OTf)(2) and visible light assisted eosin Y catalysis has been reported, providing a potential synthetic tool for the construction of pyrrolotetrahydroisoquinolines.
CHEMICAL COMMUNICATIONS
(2022)
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.
Review
Chemistry, Multidisciplinary
Sundaravel Vivek Kumar, Patrick J. Guiry
Summary: Asymmetric [3+2] cycloaddition reactions are interesting methods for synthesizing enantioenriched pyrrolidines with up to four stereocentres. Pyrrolidines are important compounds in biology and organocatalytic applications. This review summarizes the recent advancements in the enantioselective synthesis of pyrrolidines using metal catalysis, focusing on the [3+2] cycloadditions of azomethine ylides. The reactions are organized based on the type of metal catalysis and the complexity of the dipolarophile, highlighting their advantages and limitations.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Michael P. Doyle, Ming Bao
Summary: This study achieved a highly enantioselective synthesis of substituted pyrrolidines and 1,2-oxazinanes via stereoretentive [3 + 2]/[3 + 3]-cycloaddition of nonracemic donor-acceptor cyclopropanes with imines, triazines, and nitrones. The reactions were conducted under mild conditions and showed good to high yields with broad applicability. Compared to previous approaches using racemic cyclopropane reactants and chiral ligand catalysts, this study utilized enantioenriched donor-acceptor cyclopropanes as reactants with achiral catalysts.
Article
Chemistry, Applied
Chang Yoon Lee, Yong Il Kwon, Hyun Sun Jang, Sumin Lee, Yoo Lim Chun, Junyang Jung, Sung-Gon Kim
Summary: The first organocatalytic asymmetric [4+3]-cycloaddition of 2-aminophenyl alpha,beta-unsaturated carbonyls with in situ generated azaoxyallyl cations was successfully developed, leading to the synthesis of enantioenriched functionalized seven-membered 1,4-benzodiazepine-3-ones. This method was also extended to the first asymmetric [4+3]-cycloaddition of delta-hydroxy alpha,beta-unsaturated carbonyls, providing 1,4-oxazepanes in one step under mild conditions. Some of the novel adducts showed promising bioactivity in preventing peripheral nerve degeneration.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Hiroto Uno, Koki Kawai, Taichi Araki, Motoo Shiro, Norio Shibata
Summary: Gem-difluoromethylene moieties are attractive in medicinal chemistry due to their ability to mimic other more ubiquitous functional groups. A novel asymmetric method for their construction was developed, allowing easy access to chiral 1,3-dioxanes that contain a tetrasubstituted difluoroalkyl stereogenic center. The gem-difluoro substitution pattern promotes the reaction, and various substrates were suitable for this method.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Applied
Tao Wang, Bo Huang, You-Qing Wang
Summary: Using chiral phosphoric acids as organocatalysts, a formal asymmetric (4+2) cycloaddition of 3-methylene isoindolinone and in situ-generated ortho-quinone methide substrates is achieved. This reaction allows the construction of spiro chroman-isoindolinones containing spiro-N,O-heterocycles with high enantioselectivity, with a broad substrate scope.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Jia-Cheng Xu, Yi-Zhuo Yin, Zhi-Yong Han
Summary: This study presents a chiral anion-mediated asymmetric Heck/Tsuji-Trost reaction, resulting in higher yields and enantioselectivities of chiral indoline derivatives compared to previous methods based on chiral ligands. Silver carbonate functions as both base and halide scavenger, facilitating fast and recyclable exchange of the catalytic amount of chiral anions. The fast salt metathesis and acceleration effect of chiral anions both contribute to the stereocontrol of the reaction.
Article
Chemistry, Multidisciplinary
Zhi-Zhou Pan, Jia-Heng Li, Hu Tian, Liang Yin
Summary: A copper(I)-catalyzed asymmetric allylation of ketones with 2-aza-1,4-dienes has been demonstrated, providing a series of functionalized homoallyl tertiary alcohols with high to excellent enantioselectivity. The deprotonation of N-allyl-1,1-diphenylmethanimines is the rate-determining step in the reaction, generating nucleophilic allyl copper(I) species. The utility of this method has been demonstrated by the asymmetric synthesis of (R)-boivinianin A and (R)-gossonorol.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yurim Kim, Yoseop Kim, Sung-Gon Kim
Summary: This study describes a novel method for synthesizing benzosulfamidate-fused tetrahydroquinazolines. The desired compounds were obtained through cycloaddition and organocatalytic reactions, enabling the synthesis of chiral ring-fused tetrahydroquinazolines. These compounds have significant application value in biological and pharmaceutical research.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Organic
Dong-Chao Wang, Jia-Hui Liu, Yu-Qing Guan, Hai-Ming Guo
Summary: A direct dearomative [4 + 2] annulation of electron-poor N-heteroarenes with azoalkenes generated in situ from alpha- halogeno hydrazones was developed under mild conditions, leading to the synthesis of fused polycyclic tetrahydro-1,2,4-triazines with potential biological activity in high yields (up to 96%). Various alpha-halogeno hydrazones and N-heteroarenes were successfully used in this reaction, demonstrating the broad applicability of this method.
Article
Biochemistry & Molecular Biology
Si-Jia Liu, Man-Su Tu, Kai-Yue Liu, Jia-Yi Chen, Shao-Fei Ni, Yu-Chen Zhang, Feng Shi
Summary: The catalytic asymmetric [2 + 4] cycloadditions of 3-vinylindoles with ortho-quinone methides using chiral phosphoric acid as the catalyst resulted in a series of indole-containing chroman derivatives with high structural diversity, overall high yields (up to 98%), good diastereoselectivities (up to 93:7 dr), and moderate to excellent enantioselectivities (up to 98% ee).
Article
Chemistry, Organic
Yipeng Zhou, Hongwei Zhou, Jianfeng Xu
Summary: An efficient method utilizing N-heterocyclic carbene catalysis for the assembly of chiral 4,5-dihydropyridazin-3(2H)-ones is outlined. The notable features of this approach include excellent enantioselectivities, high functional group tolerance, mild reaction conditions, simple operating procedures, and compatibility with gram-scale synthesis.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Crystallography
Denise Boeck, Andreas Beuchel, Richard Goddard, Peter Imming, Ruediger W. Seidel
Summary: Two polymorphic forms of thiourea and two compounds derived from it have been studied, showing distinct crystalline forms and hydrogen bonding patterns. Compound 2 forms zigzag tapes in a polar crystal structure, while compound 3 features planar centrosymmetric dimers in a layered structure.
JOURNAL OF CHEMICAL CRYSTALLOGRAPHY
(2021)
Article
Chemistry, Multidisciplinary
Denise Boeck, Andreas Beuchel, Richard Goddard, Adrian Richter, Peter Imming, Rudiger W. Seidel
Summary: The crystal structures of two compounds show similar molecular conformations but different hydrogen bonding patterns, with one forming a three-dimensional hydrogen-bonded network and the other forming zigzag chains of hydrogen bonds.
STRUCTURAL CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Santanu Singha, Michael Buchsteiner, Giovanni Bistoni, Richard Goddard, Alois Fuerstner
Summary: The new heterobimetallic bismuth-rhodium catalysts exhibit outstanding levels of selectivity and reaction rates, with a considerably wider substrate scope, largely due to the stabilization of the chiral ligand sphere by London dispersion (LD) interactions of the peripheral silyl substituents.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Crystallography
Shabana Noor, Richard Goddard, Fehmeeda Khatoon, Sarvendra Kumar, Rudiger W. Seidel
Summary: The synthesis and structural characterization of two heterodinuclear Zn-II-Ln(III) complexes were reported, where the smaller Zn-II ion occupies the inner N2O2 compartment of the ligand while the larger and more oxophilic Ln(III) ions are found in the outer O2O2 site. The structures were revealed by X-ray crystallography, showing the formation of an asymmetrical compartmental ligand formed from N-1, N-3-bis(3-methoxysalicylidene)diethylenetriamine.
JOURNAL OF CHEMICAL CRYSTALLOGRAPHY
(2022)
Article
Chemistry, Medicinal
Adrian Richter, Ruediger W. Seidel, Juergen Graf, Richard Goddard, Christoph Lehmann, Tom Schlegel, Nour Khater, Peter Imming
Summary: This study describes new chemical transformations of two BTZ compounds and their influence on the compounds' antimycobacterial properties.
Article
Biochemistry & Molecular Biology
Hee Ra Jung, Seongman Jo, Min Jae Jeon, Hyelim Lee, Yeonjeong Chu, Jeehee Lee, Eunha Kim, Gyu Yong Song, Cheulhee Jung, Hyejin Kim, Sanghee Lee
Summary: In this study, a new chemical compound, KAS-08, was identified as an effective STING pathway activator in cancer immunotherapy. The activation of STING was achieved through direct binding or enhanced phosphorylation of STING and downstream effectors.
Article
Chemistry, Medicinal
Min Jae Jeon, Hyelim Lee, Jeehee Lee, Soo Yeon Baek, Donghee Lee, Seongman Jo, Joo-Youn Lee, Miso Kang, Hee Ra Jung, Soo Bong Han, Nam-Jung Kim, Sanghee Lee, Hyejin Kim
Summary: Stimulator of interferon genes (STING) is an endoplasmic reticulum membrane protein that plays important roles in cancer immunotherapy. Researchers have synthesized and characterized STING modulators that stimulate downstream signaling and promote immune responses, suggesting their therapeutic potential for cancer treatment.
JOURNAL OF MEDICINAL CHEMISTRY
(2022)
Article
Chemistry, Physical
Liqun Hu, Yibing Liu, Xiong Fang, Yuzhu Zheng, Rong-zhen Liao, Man Li, Youwei Xie
Summary: An activation mode for unactivated alkenes using Re2O7/HReO4 and hexafluoroisopropanol (HFIP) was described. This method enables the intermolecular hydroarylation of highly electron-deficient styrenes with various arenes, leading to the synthesis of a variety of diarylalkanes in high efficiency. The reaction conditions are mild, the substrate scope is broad, and the yields are high, with minimal waste generation. The importance of HFIP in reducing the energy barriers for key steps of the transformation was confirmed through DFT calculations and deuterium-labeling experiments.
Article
Chemistry, Medicinal
Adrian Richter, Rudiger W. Seidel, Richard Goddard, Tamira Eckhardt, Christoph Lehmann, Julia Dorner, Fabienne Siersleben, Theresia Sondermann, Lea Mann, Michael Patzer, Christian Jager, Norbert Reiling, Peter Imming
Summary: Two BTZ043-derived benzisothiazolinones (BITs) with antimycobacterial activity were reported, confirming their molecular structures. In contrast, O-acyl benzisothiazol-3-ols, which are constitutionally isomeric, showed little or no antimycobacterial activity in vitro.
ACS MEDICINAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Organic
Yibing Liu, Liqun Hu, Yuzhu Zheng, Xiong Fang, Youwei Xie
Summary: This publication describes the use of Re2O7 in HFIP to activate inert and electronically deactivated olefins for a challenging intramolecular hydroacyloxylation reaction. Both HFIP and an internal carboxy group are crucial for the successful implementation of this transformation, as they assist in the formation and stabilization of the key cationic intermediate through hydrogen-bonding interactions with ReO4-.
Article
Chemistry, Multidisciplinary
Duohang Bi, Fei Qu, Wanyue Xiao, Jiaxin Wu, Pei Liu, Hongyao Du, Youwei Xie, Hongmei Liu, Lianbin Zhang, Juan Tao, Yijing Liu, Jintao Zhu
Summary: This study developed detachable H2O2-responsive gel-based microneedle (MN) patches containing methotrexate (MTX) and epigallocatechin gallate (EGCG), which showed dual-mode drug release kinetics and improved treatment outcomes in psoriasis-like animal models. The gel-based MNs extended skin retention of EGCG, leading to prolonged ROS scavenging effects. These ROS-responsive MN patches delivered antiproliferative and anti-inflammatory drugs transdermally, demonstrating potential for improved psoriasis treatment.
Article
Multidisciplinary Sciences
Hongmei Liu, Qing Huang, Rong-zhen Liao, Man Li, Youwei Xie
Summary: In this article, the authors challenge the traditional mechanism of transetherification between ethers and alcohols by using Re2O7-mediated annulation. They demonstrate that the activation of the alcohol hydroxy group followed by nucleophilic attack of the ether, instead of ether activation, is the primary step in this reaction. This alternative mechanism is suitable for substrates with multiple ether moieties, which is unprecedented in previous methods.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Yuzhu Zheng, Xiong Fang, Wen-Hao Deng, Bin Zhao, Rong-Zhen Liao, Youwei Xie
Summary: This manuscript presents a general method for the intramolecular dehydrative Friedel-Crafts reaction of alcohols catalyzed by Re2O7. The optimized conditions allow for efficient synthesis of various pharmaceutically important organic scaffolds. The potential application of this method is demonstrated through the synthesis of several commercially available drugs or biologically relevant molecules. DFT calculations suggest that Re2O7 prefers activation of hydroxyl groups through ester formation and heterolytic cleavage of C-O bonds.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Microbiology
Kyungseob Noh, Eun Ju Jeong, Timothy An, Jin Soo Shin, Hyejin Kim, Soo Bong Han, Meehyein Kim
Summary: This study investigated the use of a TLR7/8 agonist, compound 31, as an adjuvant to enhance the immune response to an inactivated influenza A virus vaccine. The results showed that compound 31 not only increased the production of virus-specific antibodies but also effectively neutralized the influenza A virus. In addition, the combination of compound 31 and the vaccine reduced viral infection-mediated weight loss and improved survival rates in a virus-challenge model. These findings suggest that compound 31 has potential as a mucosal vaccine adjuvant for respiratory RNA viruses.
JOURNAL OF MICROBIOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Michael Patzer, Nils Noethling, Richard Goddard, Christian W. Lehmann
Summary: X-ray crystallography allows for the determination of the absolute configuration of small bioactive organic molecules. In this study, the absolute configuration of the flavoring agent (+)-gamma-decalactone was determined through single crystal analysis. The molecule consists of a linear aliphatic non-polar backbone and a polar lactone head, with observations of layers alternating along the c-axis in the solid state.
CHEMISTRY-SWITZERLAND
(2021)
