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Wai H, Koelblen T, Hayes ME, Burris TP, Micalizio GC. Progress toward the De Novo Asymmetric Synthesis of Euphanes. Org Lett 2022; 24:3686-3690. [PMID: 35584298 DOI: 10.1021/acs.orglett.2c01299] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Progress toward an asymmetric synthesis of euphanes is described. A C14-desmethyl euphane system possessing five differentially substituted and electronically distinct alkenes has been prepared. The route employed is based on sequential metallacycle-mediated annulative cross-coupling, double asymmetric Brønsted acid mediated intramolecular Friedel-Crafts alkylation, and an oxidative rearrangement to establish the requisite C10 quaternary center. These studies have also led to the discovery of a novel euphane-based modulator of the Liver X Receptor.
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Affiliation(s)
- HtooTint Wai
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Thomas Koelblen
- University of Florida, Genetics Institute, Gainesville, Florida 32610, United States
| | - Matthew E Hayes
- University of Florida, Genetics Institute, Gainesville, Florida 32610, United States
| | - Thomas P Burris
- University of Florida, Genetics Institute, Gainesville, Florida 32610, United States
| | - Glenn C Micalizio
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
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2
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Nicholson JM, Millham AB, Bucknam AR, Markham LE, Sailors XI, Micalizio GC. General Enantioselective and Stereochemically Divergent Four-Stage Approach to Fused Tetracyclic Terpenoid Systems. J Org Chem 2022; 87:3352-3362. [PMID: 35175755 PMCID: PMC9438405 DOI: 10.1021/acs.joc.1c02979] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Tetracyclic terpenoid-derived natural products are a broad class of medically relevant agents that include well-known steroid hormones and related structures, as well as more synthetically challenging congeners such as limonoids, cardenolides, lanostanes, and cucurbitanes, among others. These structurally related compound classes present synthetically disparate challenges based, in part, on the position and stereochemistry of the numerous quaternary carbon centers that are common to their tetracyclic skeletons. While de novo syntheses of such targets have been a topic of great interest for over 50 years, semisynthesis is often how synthetic variants of these natural products are explored as biologically relevant materials and how such agents are further matured as therapeutics. Here, focus was directed at establishing an efficient, stereoselective, and molecularly flexible de novo synthetic approach that could offer what semisynthetic approaches do not. In short, a unified strategy to access common molecular features of these natural product families is described that proceeds in four stages: (1) conversion of epichlorohydrin to stereodefined enynes, (2) metallacycle-mediated annulative cross-coupling to generate highly substituted hydrindanes, (3) tetracycle formation by stereoselective forging of the C9-C10 bond, and (4) group-selective oxidative rearrangement that repositions a quaternary center from C9 to C10. These studies have defined the structural features required for highly stereoselective C9-C10 bond formation and document the generality of this four-stage synthetic strategy to access a range of unique stereodefined systems, many of which bear stereochemistry/substitution/functionality not readily accessible from semisynthesis.
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Affiliation(s)
- Joshua M. Nicholson
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Adam B. Millham
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Andrea R. Bucknam
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Lauren E. Markham
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Xenia Ivanna Sailors
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Glenn C. Micalizio
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
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3
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Stöckl Y, Fellmeth T, Bauer F, Wank B, Frey W, Claasen B, Zens A, Köhn A, Laschat S. Chasing polycyclic natural products: 5/6/5‐ or 5/6/6‐carbotricyclic scaffold construction via stereodivergent Diels‐Alder reaction of chiral hydrindanes and their boron complexes. European J Org Chem 2022. [DOI: 10.1002/ejoc.202101416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yannick Stöckl
- Universität Stuttgart: Universitat Stuttgart Institut für Organische Chemie GERMANY
| | - Thomas Fellmeth
- University of Stuttgart: Universitat Stuttgart Institut für Theoretische Chemie GERMANY
| | - Florian Bauer
- University of Stuttgart: Universitat Stuttgart Institut für Theoretische Chemie GERMANY
| | - Bianca Wank
- Universität Stuttgart: Universitat Stuttgart Institut für Organische Chemie GERMANY
| | - Wolfgang Frey
- Universität Stuttgart: Universitat Stuttgart Institut für Organische Chemie GERMANY
| | - Birgit Claasen
- Universität Stuttgart: Universitat Stuttgart Institut für Organische Chemie GERMANY
| | - Anna Zens
- Universität Stuttgart: Universitat Stuttgart Institut für Organische Chemie GERMANY
| | - Andreas Köhn
- Universität Stuttgart: Universitat Stuttgart Institut für Theoretische Chemie GERMANY
| | - Sabine Laschat
- Universität Stuttgart Institut für Organische Chemie Pfaffenwaldring 55 70569 Stuttgart GERMANY
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Markham L, Tolbert JD, Kull FJ, Midgett CR, Micalizio GC. An Enantiodefined Conformationally Constrained Fatty Acid Mimetic and Potent Inhibitor of ToxT. ACS Med Chem Lett 2021; 12:1493-1497. [PMID: 34531958 PMCID: PMC8436414 DOI: 10.1021/acsmedchemlett.1c00378] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 08/20/2021] [Indexed: 11/29/2022] Open
Abstract
The chiral conformation that palmitoleic acid takes when it is bound to ToxT, the master regulator of virulence genes in the bacterial pathogen Vibrio cholerae, was used as inspiration to design a novel class of fatty acid mimetics. The best mimetic, based on a chiral hydrindane, was found to be a potent inhibitor of this target. The synthetic chemistry that enabled these studies was based on the sequential use of a stereoselective annulative cross-coupling reaction and dissolving metal reduction to establish the C13 and C9 stereocenters, respectively.
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Affiliation(s)
- Lauren
E. Markham
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Jessica D. Tolbert
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - F. Jon Kull
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Charles R. Midgett
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Glenn C. Micalizio
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
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5
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Millham AB, Bhatt CP, Micalizio GC. From Metallacycle-Mediated Annulative Cross-Coupling to Steroidal Tetracycles through Intramolecular C9-C10 Bond Formation. Org Lett 2020; 22:6595-6599. [PMID: 32806140 DOI: 10.1021/acs.orglett.0c02358] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
While semisynthesis is a common platform for medicinal investigation of steroidal systems, varying the nature of substitution and stereochemistry at C9 and C10 remains challenging. It is demonstrated here that de novo synthesis, enabled by a metallacycle-centered annulation reaction, provides a uniquely effective means of addressing this problem. In short, double asymmetric Friedel-Crafts cyclization proved most effective for establishing anti- relative stereochemistry (with respect to C13), while an intramolecular Heck reaction reliably delivered the syn- diastereomers with high selectivity. In addition, these studies reveal that this oxidative rearrangement is effective for establishing a C10 quaternary center boasting variable alkyl or aryl substitution.
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Affiliation(s)
- Adam B Millham
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Chinmay P Bhatt
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
| | - Glenn C Micalizio
- Department of Chemistry, Dartmouth College, Burke Laboratory, Hanover, New Hampshire 03755, United States
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Indu S, Kaliappan KP. Synthetic approaches towards cortistatins: evolution and progress through its ages. Org Biomol Chem 2020; 18:3965-3995. [PMID: 32420567 DOI: 10.1039/d0ob00770f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cortistatins are a family of steroidal alkaloids with a unique pentacyclic skeleton, having immensely potent anti-angiogenetic activities. Given the scarcity in the natural availability of these compounds, their syntheses became major attractions in organic chemistry. Along with total synthesis of the most potent congeners in the family: cortistatins A and J, the synthesis of two other members have been successfully completed, while various other analogues have also been designed with variable degrees of biological activities. This review is an exhaustive coverage of the significant attempts towards constructing this highly challenging molecule and also aims to highlight the deep understanding of the structure-activity relationships of these compounds, which have been garnered over time.
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Affiliation(s)
- Satrajit Indu
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
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Bao W, Tao Y, Cheng J, Huang J, Cao J, Zhang M, Ye W, Wang B, Li Y, Zhu L, Lee CS. In(OTf) 3-Catalyzed Cascade Cyclization for Construction of Oxatricyclic Compounds. Org Lett 2018; 20:7912-7915. [PMID: 30543298 DOI: 10.1021/acs.orglett.8b03461] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A highly diastereoselective cascade cyclization reaction has been developed for establishing a series of oxatricyclic compounds using Chan's diene and simple keto alkynal substrates with only 1 mol % of In(OTf)3 as the catalyst in 82-92% yields. The potential utility of this synthetic strategy has been demonstrated in model studies for the construction the core structures of 1α,8α:4α,5α-diepoxy-4,5-dihydroosmitopsin and cortistatin A.
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Affiliation(s)
- Wenli Bao
- Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology , Peking University Shenzhen Graduate School , Shenzhen University Town, Xili, Shenzhen 518055 , China
| | - Yezi Tao
- Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology , Peking University Shenzhen Graduate School , Shenzhen University Town, Xili, Shenzhen 518055 , China
| | - Jiangqun Cheng
- Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology , Peking University Shenzhen Graduate School , Shenzhen University Town, Xili, Shenzhen 518055 , China
| | - Junrong Huang
- Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology , Peking University Shenzhen Graduate School , Shenzhen University Town, Xili, Shenzhen 518055 , China
| | - Jingming Cao
- Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology , Peking University Shenzhen Graduate School , Shenzhen University Town, Xili, Shenzhen 518055 , China
| | - Mengxun Zhang
- Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology , Peking University Shenzhen Graduate School , Shenzhen University Town, Xili, Shenzhen 518055 , China
| | - Weijian Ye
- Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology , Peking University Shenzhen Graduate School , Shenzhen University Town, Xili, Shenzhen 518055 , China
| | - Bo Wang
- Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology , Peking University Shenzhen Graduate School , Shenzhen University Town, Xili, Shenzhen 518055 , China
| | - Yang Li
- Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology , Peking University Shenzhen Graduate School , Shenzhen University Town, Xili, Shenzhen 518055 , China
| | - Lizhi Zhu
- Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology , Peking University Shenzhen Graduate School , Shenzhen University Town, Xili, Shenzhen 518055 , China.,Institute of Translational Medicine, Shenzhen Second People's Hospital , The First Affiliated Hospital of Shenzhen University, Health Science Center , Shenzhen 518035 , China
| | - Chi-Sing Lee
- Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology , Peking University Shenzhen Graduate School , Shenzhen University Town, Xili, Shenzhen 518055 , China.,Institute of Research and Continuing Edition (Shenzhen) , Hong Kong Baptist University , Industrialization Complex Building, Shenzhen Virtual University Park, Shenzhen 518000 , China.,Department of Chemistry , Hong Kong Baptist University , Kowloon Tong , Hong Kong SAR
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8
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A rearranged seco-steroid with new skeleton and five new abnormal progesteroids from Nodulisporium sp. Tetrahedron 2018. [DOI: 10.1016/j.tet.2018.08.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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9
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Liu L, Cheng HL, Ma WQ, Hou SH, Tu YQ, Zhang FM, Zhang XM, Wang SH. Improved synthesis of 8-oxabicyclo[3.2.1]octanes via tandem C-H oxidation/oxa-[3,3] Cope rearrangement/aldol cyclization. Chem Commun (Camb) 2018; 54:196-199. [PMID: 29226934 DOI: 10.1039/c7cc08511g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A tandem C-H oxidation/oxa-[3,3] Cope rearrangement/aldol reaction of allylic silylethers promoted by T+BF4-(tempo oxoammonium tetrafluoroborate)/ZnBr2 has been successfully developed allowing the efficient construction of 8-oxabicyclo[3.2.1]octanes and their analogs with a wide substrate scope.
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Affiliation(s)
- Lin Liu
- State Key Laboratory of Applied Organic Chemistry & School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China.
| | - Hai-Long Cheng
- State Key Laboratory of Applied Organic Chemistry & School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China.
| | - Wen-Qiang Ma
- State Key Laboratory of Applied Organic Chemistry & School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China.
| | - Si-Hua Hou
- State Key Laboratory of Applied Organic Chemistry & School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China.
| | - Yong-Qiang Tu
- State Key Laboratory of Applied Organic Chemistry & School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China. and School of Chemistry & Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China.
| | - Fu-Min Zhang
- State Key Laboratory of Applied Organic Chemistry & School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China.
| | - Xiao-Ming Zhang
- State Key Laboratory of Applied Organic Chemistry & School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China.
| | - Shao-Hua Wang
- State Key Laboratory of Applied Organic Chemistry & School of Pharmacy, Lanzhou University, Lanzhou 730000, P. R. China.
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Micalizio GC, Mizoguchi H. The Development of Alkoxide-Directed Metallacycle-Mediated Annulative Cross-Coupling Chemistry. Isr J Chem 2017; 57:228-238. [PMID: 28652644 PMCID: PMC5482546 DOI: 10.1002/ijch.201600098] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Alkoxide-directed metallacycle-mediated cross-coupling is a rapidly growing area of reaction methodology in organic chemistry. Over the last decade, developments have resulted in > thirty new and highly selective intermolecular (or "convergent") C-C bond-forming reactions that have established powerful retrosynthetic relationships in stereoselective synthesis. While early studies were focused on developing transformations that forge a single C-C bond by way of a functionalized and unsaturated metallacyclopentane intermediate, recent advances mark the ability to employ this organometallic intermediate in additional stereoselective transformations. Among these more advanced coupling processes, those that embrace the metallacycle in subsequent [4+2] chemistry have resulted in the realization of a number of highly selective annulative cross-coupling reactions that deliver densely functionalized and angularly substituted carbocycles. This review discusses the early development of this chemistry, recent advances in reaction methodology, and shares a glimpse of the power of these processes in natural product synthesis.
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Mizoguchi H, Micalizio GC. Synthesis of Angularly Substituted trans-Fused Decalins through a Metallacycle-Mediated Annulative Cross-Coupling Cascade. Angew Chem Int Ed Engl 2016; 55:13099-13103. [PMID: 27634059 PMCID: PMC5056368 DOI: 10.1002/anie.201606962] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Indexed: 01/07/2023]
Abstract
A convergent coupling reaction is described that enables the stereoselective construction of angularly substituted trans-fused decalins from acyclic precursors. The process builds on our alkoxide-directed titanium-mediated alkyne-alkyne coupling and employs a 1,7-enyne coupling partner. Overall, the reaction is thought to proceed through initial formation of a tetrasusbstituted metallacyclopentadiene, stereoselective intramolecular [4+2] cycloaddition, elimination, isomerization, and regio- and stereoselective protonation. Distinct from our early studies directed at the synthesis of trans-fused hydrindanes, the current annulative coupling reveals an important effect of TMSCl in controlling the final protonation-the event that establishes the stereochemistry of the ring fusion.
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Affiliation(s)
- Haruki Mizoguchi
- Department of Chemistry, Dartmouth College, 6128 Burke Laboratory, Hanover, NH, 03755, USA
| | - Glenn C Micalizio
- Department of Chemistry, Dartmouth College, 6128 Burke Laboratory, Hanover, NH, 03755, USA.
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12
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Mizoguchi H, Micalizio GC. Synthesis of Angularly Substituted trans
-Fused Decalins through a Metallacycle-Mediated Annulative Cross-Coupling Cascade. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201606962] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Haruki Mizoguchi
- Department of Chemistry; Dartmouth College; 6128 Burke Laboratory Hanover NH 03755 USA
| | - Glenn C. Micalizio
- Department of Chemistry; Dartmouth College; 6128 Burke Laboratory Hanover NH 03755 USA
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