Review
Chemistry, Multidisciplinary
Debobrata Paul, Ashis Kundu, Sanu Saha, Rajib Kumar Goswami
Summary: This feature article highlights total synthesis as a reliable tool for confirming the structure of natural products. Despite advances in spectroscopic techniques, structural misassignments of natural products remain common. Recent case studies have shown that chemical synthesis can be used to revise the structures of natural products.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Organic
Yiding Wang, Lei Shen, Helin Wang, Yixin Luo, Qingle Zeng
Summary: The ring-opening addition reaction of activated vinyl cyclopropanes with N-tosylhydrazones in the presence of palladium(0) and triphenylphosphine yields N-tosylhydrazone butenylmalonate compounds. Aromatic aldehyde-derived N-tosylhydrazones produce both terminal and internal N-allylated products, with the terminal products being the major ones. On the other hand, ketone-derived tosylhydrazones only yield terminal addition products. The transformation relationship between the terminal and internal N-allylated products is also observed. A reasonable mechanism based on preliminary experimental results is proposed.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Lorenz E. Loeffler, Conny Wirtz, Alois Fuerstner
Summary: This paper presents a new approach to chemical synthesis that allows for the preparation of a variety of casbane derivatives, especially the more highly oxygenated and arguably more relevant members of the family. Key design elements include catalyst-controlled intramolecular cyclopropanation, chain extension of stereoisomeric cyclopropane building blocks, and ring-closing alkyne metathesis. The concise total syntheses of depressin, yuexiandajisu A, and ent-pekinenin C demonstrate the effectiveness of this method.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Ya-Jian Hu, Chen-Chen Gu, Xin-Feng Wang, Long Min, Chuang-Chuang Li
Summary: Taxol is a famous natural diterpenoid and important anticancer medicine with synthetic challenges. This study presents an asymmetric total synthesis of Taxol through a concise approach and the efficient construction of the challenging eight-membered ring. The new convergent approach allows for the creation of Taxol derivatives for further biological research.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Jiujian Ji, Jiajun Chen, Sixun Qin, Wanye Li, Jun Zhao, Guozhao Li, Hao Song, Xiao-Yu Liu, Yong Qin
Summary: This article reports the first total synthesis of vilmoraconitine using efficient ring-forming reactions. Key steps include an oxidative dearomatization-induced Diels-Alder cycloaddition, a hydrodealkenylative fragmentation/Mannich sequence, and an intramolecular Diels-Alder cycloaddition.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Sayan Ray, Subhajit Mondal, Santanu Mukherjee
Summary: In this study, a total synthesis of [3]-ladderanol was achieved using a novel desymmetrizing reaction strategy. The synthetic method is concise and efficient, and can be applied to the synthesis of similar molecules.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Xikang Zheng, Yan Li, Mengtie Guan, Lingyue Wang, Shilong Wei, Yi-Cheng Li, Chin-Yuan Chang, Zhengren Xu
Summary: A unified strategy for the biomimetic total synthesis of the spiroindimicin family of natural products was reported. Key transformations include one-pot two-enzyme-catalyzed oxidative dimerization and regioselective bond formation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Biochemistry & Molecular Biology
Ramsha Munir, Ameer Fawad Zahoor, Sadia Javed, Bushra Parveen, Asim Mansha, Ahmad Irfan, Samreen Gul Khan, Ali Irfan, Katarzyna Kotwica-Mojzych, Mariusz Mojzych
Summary: Simmons-Smith cyclopropanation is a widely used reaction in organic synthesis for the conversion of alkenes into cyclopropane. It is an important reaction because cyclopropane is a key intermediate in the synthesis of biologically active natural compounds. The modified form of this reaction using Et2Zn and CH2I2 has been successfully applied in the total synthesis of complex natural products with diverse biological activities. This review provides an overview of the Furukawa-modified Simmons-Smith cyclopropanation from 2005 to 2022.
Article
Chemistry, Organic
Sebastian Fischer, Terrence-Thang H. Nguyen, Andreas Ratzenboeck, Huw M. L. Davies, Oliver Reiser
Summary: A stereoselective, solvent- and metal-free method for endocyclic C-C bond cleavage of monocyclopropanated cyclopentadienes mediated by strong acids has been developed. It leads to the formation of highly functionalized six-membered carbocycles with high stereocontrol. The critical step involves the formation of a cyclopropyl carbocation that undergoes endocyclic ring opening through an SN2'-type attack of various nucleophiles. Subsequent synthetic transformations demonstrate the versatility of the resulting cyclohexenes for the synthesis of compounds with nonconventional substitution patterns.
Review
Chemistry, Multidisciplinary
Huilin Li, Jing Zhang, Xuegong She
Summary: This MiniReview demonstrates the achievements in the construction of the diquinane ring system in the past decade, discussing the strategic synthesis of the diquinane unit and its impact on the field of natural product total synthesis.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Nicole Hauser, Michael A. Imhof, Sarah S. Eichenberger, Tomas Kundig, Erick M. Carreira
Summary: The first total syntheses of the indole diterpenoids (+)-shearinine G and D were achieved through late-stage coupling, diastereoselective intramolecular cyclopropanation, Sharpless dihydroxylation/Achmatowicz reaction, and Prins cyclization. Tuning of the substituents on the parent arylcarboxaldehyde led to divergent products, further transformed into shearinines G and D, with unexpected stereochemical outcomes in the Riley-type oxidation of a bicyclic enone.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Suo Chen, Yizhi Zhang, Shanshan Liu, Xiao Shen
Summary: We report the invention of a novel carbene precursor, (1-diazo-2,2,2-trifluoroethyl)dimethyl(phenyl)silane (1a) and its application in the synthesis of (difluoromethylene)cyclopropanes. The reaction proceeds through photocatalyzed [2+1] cyclization of readily available alkenes and diazo compound 1a followed by the work-up of the reaction through the elimination of silyl fluoride. Both aromatic and aliphatic alkenes are tolerated by the mild reaction conditions, affording various (difluoromethylene)cyclopropanes in 44%-82% yield (>30 examples). The synthetic potential of this methodology is highlighted by gram scale reaction and diversified downstream transformations. Experimental and DFT calculations suggest the involvement of triplet carbene intermediate.
SCIENCE CHINA-CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Haoran Dong, Dachao Hu, Benke Hong, Jin Wang, Xiaoguang Lei
Summary: The first total syntheses of four natural antibiotics, vermisporin, PF1052/AB4015-A, AB4015-L, AB4015-B, and one hydrogenated natural product derivative, AB4015-A2, featuring a tetramic acid bearing cis-decalin ring, are reported. The functionalized cis-decalin ring was constructed via a diastereoselective intramolecular Diels-Alder (IMDA) reaction, with a rare endo-boat transition state. The efficient installation of the sterically hindered epoxy group in vermisporin, PF1052/AB4015-A, and AB4015-L was achieved through an intramolecular neighboring-group-oriented strategy, and the desired tetramic acid structure was obtained through a one-pot aminolysis/Dieckmann condensation cascade using L-amino acid derivatives. The total synthesis allowed for the unequivocal verification of the absolute configuration of these natural products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Isaiah K. Eckart-Frank, Sidney M. Wilkerson-Hill
Summary: In this study, we demonstrated the usage of E/Z mixtures of α,α-disubstituted crotylhydrazones to selectively obtain spirocyclic vinylcyclobutanes. We provided 24 examples of a 1,1-insertion/4-exo-trig tandem process for generating these motifs. Additionally, spirocyclic alkylidenecyclobutanes can also be obtained using α,α-disubstituted allylated hydrazones (11 examples). We found that the migrating group greatly influences the course of the reaction, with bromoenones yielding allylic C-H insertion products in good yields. Furthermore, Pd(0) in the absence of aryl or alkenyl bromides results in an intramolecular cyclopropanation reaction to form [2.1.0]-bicycles.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Review
Chemistry, Multidisciplinary
Soumik De, Aritra Kumar Dan, Raghaba Sahu, Sagarika Parida, Debadutta Das
Summary: Gold catalysis is a popular and highly innovative field in catalysis research, providing new approaches for chemical transformations from simple starting materials. The application of gold catalysis in the total synthesis of natural products has successfully addressed complex challenges and achieved significant progress.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
