1
|
Hou J, Fan H, Zhang X, Liu X, Chen J, Lv G, He S, Hai L, Yang Z, Wu Y. Organic Photoredox-Catalyzed Site-Selective Alkylation of Glycine Derivatives and Peptides via Infrequent 1,2-Hydrogen Atom Transfer of Amidyl Radicals. Org Lett 2024; 26:7638-7643. [PMID: 39230392 DOI: 10.1021/acs.orglett.4c02742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
Herein, we disclose a visible-light-driven photoredox-catalyzed protocol for site-selective alkylation of glycine derivatives via 1,2-hydrogen atom transfer, which is distinguished by metal free and mild conditions, high chemoselectivity, and good functional group compatibility. This protocol provides a unique approach for synthesizing valuable α,β-diamino acid derivatives. Furthermore, the potential synthetic merit of this transformation is proven by a scale-up reaction and late-stage functionalization of peptides.
Collapse
Affiliation(s)
- Jinyu Hou
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Department of Medicinal Chemistry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, No. 17 Southern Renmin Road, Chengdu, Sichuan 610041, People's Republic of China
| | - Hongying Fan
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Department of Medicinal Chemistry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, No. 17 Southern Renmin Road, Chengdu, Sichuan 610041, People's Republic of China
| | - Xue Zhang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Department of Medicinal Chemistry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, No. 17 Southern Renmin Road, Chengdu, Sichuan 610041, People's Republic of China
| | - Xingyu Liu
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Department of Medicinal Chemistry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, No. 17 Southern Renmin Road, Chengdu, Sichuan 610041, People's Republic of China
| | - Jian Chen
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Department of Medicinal Chemistry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, No. 17 Southern Renmin Road, Chengdu, Sichuan 610041, People's Republic of China
| | - Guanghui Lv
- Department of Pharmacy, Hubei Provincial Clinical Research Center for Umbilical Cord Blood Hematopoietic Stem Cells, Taihe Hospital, Hubei University of Medicine, Shiyan 442000, Hubei, China
| | - Shiyun He
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Department of Medicinal Chemistry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, No. 17 Southern Renmin Road, Chengdu, Sichuan 610041, People's Republic of China
| | - Li Hai
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Department of Medicinal Chemistry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, No. 17 Southern Renmin Road, Chengdu, Sichuan 610041, People's Republic of China
| | - Zhongzhen Yang
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041 China
| | - Yong Wu
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Department of Medicinal Chemistry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, No. 17 Southern Renmin Road, Chengdu, Sichuan 610041, People's Republic of China
| |
Collapse
|
2
|
Pünner F, Sohtome Y, Lyu Y, Hashizume D, Akakabe M, Yoshimura M, Yashiroda Y, Yoshida M, Sodeoka M. Catalytic Aerobic Carbooxygenation for the Construction of Vicinal Tetrasubstituted Centers: Application to the Synthesis of Hexasubstituted γ-Lactones. Angew Chem Int Ed Engl 2024; 63:e202405876. [PMID: 39031750 DOI: 10.1002/anie.202405876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/30/2024] [Accepted: 06/19/2024] [Indexed: 07/22/2024]
Abstract
Strategic design for the construction of contiguous tetrasubstituted carbon centers represents a daunting challenge in synthetic organic chemistry. Herein, we report a combined experimental and computational investigation aimed at developing catalytic aerobic carbooxygenation, involving the intramolecular addition of tertiary radicals to geminally disubstituted alkenes, followed by aerobic oxygenation. This reaction provides a straightforward route to various α,α,β,β-tetrasubstituted γ-lactones, which can be readily transformed into hexasubstituted γ-lactones through allylation/translactonization. Computational analysis reveals that the key mechanistic foundation for achieving the developed aerobic carbooxygenation involves the design of endothermic (energetically uphill) C-C bond formation followed by exothermic (energetically downhill) oxygenation. Furthermore, we highlight a unique fluorine-induced stereoelectronic effect that stabilizes the endothermic stereodetermining transition state.
Collapse
Affiliation(s)
- Florian Pünner
- Synthetic Organic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, 351-0198, Saitama, Japan
- Catalysis and Integrated Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, 351-0198, Saitama, Japan
| | - Yoshihiro Sohtome
- Synthetic Organic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, 351-0198, Saitama, Japan
- Catalysis and Integrated Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, 351-0198, Saitama, Japan
- Organic & Biomolecular Chemistry Laboratory Department of Applied Chemistry College of Life Sciences, Ritsumeikan University, Kusatsu, 525-8577, Shiga, Japan
| | - Yanzong Lyu
- Catalysis and Integrated Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, 351-0198, Saitama, Japan
| | - Daisuke Hashizume
- Materials Characterization Support Team, RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, 351-0198, Saitama, Japan
| | - Mai Akakabe
- Synthetic Organic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, 351-0198, Saitama, Japan
- Catalysis and Integrated Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, 351-0198, Saitama, Japan
| | - Mami Yoshimura
- Molecular Ligand Target Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, 351-0198, Saitama, Japan
| | - Yoko Yashiroda
- Molecular Ligand Target Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, 351-0198, Saitama, Japan
| | - Minoru Yoshida
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, 351-0198, Saitama, Japan
| | - Mikiko Sodeoka
- Synthetic Organic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, 351-0198, Saitama, Japan
- Catalysis and Integrated Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, 351-0198, Saitama, Japan
| |
Collapse
|
3
|
Yamada Y, Yoshinaga R, Matsui Y, Nagatomo M, Fujino H, Inoue M. Et 3Al/Light-Promoted Radical-Polar Crossover Reactions of α-Alkoxyacyl Tellurides. J Org Chem 2024; 89:11701-11706. [PMID: 39110480 DOI: 10.1021/acs.joc.4c01445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Here, we report new radical-polar crossover reactions of α-alkoxy carbon radicals for constructing highly oxygenated molecules with contiguous stereocenters. The method employs a 370 nm UV light-emitting diode (LED) for the photoexcitation of α-alkoxyacyl telluride, and Et3Al as the radical initiator and terminator. First, Et3Al and UV LED promoted radical coupling between the α-alkoxyacyl telluride and cyclopentenone via C-Te bond homolysis, CO expulsion, and C-C bond formation. Second, Et3Al converted the radical species to the corresponding aluminum enolate. Third, the second C-C bond formation occurred via a polar mechanism: intermolecularly with aldehydes/ketones and intramolecularly with epoxide, producing aldol and SN2 adducts, respectively. The present coupling reactions increase the molecular complexity in a single step by stereoselective formation of the two hindered C-C bonds. The devised method is expected to be useful for the expeditious assembly of densely oxygenated natural products.
Collapse
Affiliation(s)
- Yutaro Yamada
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Risa Yoshinaga
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yuki Matsui
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Masanori Nagatomo
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Haruka Fujino
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| |
Collapse
|
4
|
Huang M, Sun H, Seufert F, Friedrich A, Marder TB, Hu J. Photoredox/Cu-Catalyzed Decarboxylative C(sp 3)-C(sp 3) Coupling to Access C(sp 3)-Rich gem-Diborylalkanes. Angew Chem Int Ed Engl 2024; 63:e202401782. [PMID: 38818649 DOI: 10.1002/anie.202401782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 05/28/2024] [Accepted: 05/28/2024] [Indexed: 06/01/2024]
Abstract
gem-Diborylalkanes are highly valuable building blocks in organic synthesis and pharmaceutical chemistry due to their ability to participate in multi-step cross-coupling transformations, allowing for the rapid generation of molecular complexity. While progress has been made in their synthetic metholodology, the construction of β-tertiary and C(sp3)-rich gem-diborylalkanes remains a synthetic challenge due to substrate limitations and steric hindrance issues. An approach is presented that utilizes synergistic photoredox and copper catalysis to achieve efficient C(sp3)-C(sp3) cross-coupling of alkyl N-hydroxyphthalimide esters, which can easily be obtained from alkyl carboxylic acids, with diborylmethyl species, providing a series of C(sp3)-rich gem-diborylalkanes with 1°, 2°, and even 3° β positions. Furthermore, this approach can also be applied to complex medicinal compounds and natural products, offering rapid access to molecular complexity and late-stage functionalization of C(sp3)-rich drug candidates. Mechanistic experiments revealed that diborylmethyl Cu(I) species participated in both the photoredox process and the key C(sp3)-C(sp3) bond-forming step.
Collapse
Affiliation(s)
- Mingming Huang
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Huaxing Sun
- State Key Laboratory of Organic Electronics and Information Displays & & Institute of Advanced Materials (IAM), College of Chemistry and Life Sciences, Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing, 210023, China
| | - Florian Seufert
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Alexandra Friedrich
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Todd B Marder
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Jiefeng Hu
- State Key Laboratory of Organic Electronics and Information Displays & & Institute of Advanced Materials (IAM), College of Chemistry and Life Sciences, Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing, 210023, China
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| |
Collapse
|
5
|
Shan Q, Wu Y, Chen M, Zhao X, Loh T, Hu X. Synergistic Copper-Aminocatalysis for Direct Tertiary α-Alkylation of Ketones with Electron-Deficient Alkanes. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2402255. [PMID: 38885363 PMCID: PMC11336924 DOI: 10.1002/advs.202402255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Revised: 05/17/2024] [Indexed: 06/20/2024]
Abstract
In this study, a novel approach for the tertiary α-alkylation of ketones using alkanes with electron-deficient C─H bonds is presented, employing a synergistic catalytic system combining inexpensive copper salts with aminocatalysis. This methodology addresses the limitations of traditional alkylation methods, such as the need for strong metallic bases, regioselectivity issues, and the risk of over alkylation, by providing a high reactivity and chemoselectivity without the necessity for pre-functionalized substrates. The dual catalytic strategy enables the direct functionalization of C(sp3)─H bonds, demonstrating remarkable selectivity in the presence of conventional C(sp3)─H bonds that are adjacent to heteroatoms or π systems, which are typically susceptible to single-electron transfer processes. The findings contribute to the advancement of alkylation techniques, offering a practical and efficient route for the construction of C(sp3)─C(sp3) bonds, and paving the way for further developments in the synthesis of complex organic molecules.
Collapse
Affiliation(s)
- Qi‐Chao Shan
- Institute of Advanced SynthesisSchool of Chemistry and Molecular EngineeringNanjing Tech University30 South Puzhu RoadNanjing211816China
| | - You‐Wei Wu
- Institute of Advanced SynthesisSchool of Chemistry and Molecular EngineeringNanjing Tech University30 South Puzhu RoadNanjing211816China
| | - Mu‐Xiang Chen
- Institute of Advanced SynthesisSchool of Chemistry and Molecular EngineeringNanjing Tech University30 South Puzhu RoadNanjing211816China
| | - Xuefei Zhao
- Institute of Advanced SynthesisSchool of Chemistry and Molecular EngineeringNanjing Tech University30 South Puzhu RoadNanjing211816China
| | - Teck‐Peng Loh
- College of Advanced Interdisciplinary Science and TechnologyHenan University of Technology100 Lianhua StreetZhengzhou450001China
- Division of Chemistry and Biological ChemistrySchool of ChemistryChemical Engineering and BiotechnologyNanyang Technological University21 Nanyang LinkSingapore637371Singapore
| | - Xu‐Hong Hu
- Institute of Advanced SynthesisSchool of Chemistry and Molecular EngineeringNanjing Tech University30 South Puzhu RoadNanjing211816China
| |
Collapse
|
6
|
Dao N, Gan XC, Shenvi RA. Metal-Hydride C-C Cross-Coupling of Alkenes Through a Double Outer-Sphere Mechanism. J Org Chem 2024. [PMID: 38926670 DOI: 10.1021/acs.joc.4c00260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
This Synopsis covers recent reports of metal-catalyzed alkene functionalizations that likely involve iterative outer-sphere reactions in which the substrate reacts directly with a metal ligand instead of with the metal center itself. Traditional metal hydride-catalyzed alkene functionalizations involve this latter pathway whereby the alkene forms part of the metal ligand sphere (i.e. an inner-sphere reaction). In contrast, alkenes do not ligate the metal in so-called outer-sphere reactions and instead react with a metal ligand. These transformations have proved crucial for the synthesis of high fraction sp3 (Fsp3) targets, especially in hindered fragment couplings of relevance to natural product space.
Collapse
Affiliation(s)
- Nathan Dao
- Department of Chemistry, Scripps Research, La Jolla, California 92037, United States
- Graduate School of Chemical and Biological Sciences, Scripps Research, La Jolla, California 92037, United States
| | - Xu-Cheng Gan
- Department of Chemistry, Scripps Research, La Jolla, California 92037, United States
| | - Ryan A Shenvi
- Department of Chemistry, Scripps Research, La Jolla, California 92037, United States
- Graduate School of Chemical and Biological Sciences, Scripps Research, La Jolla, California 92037, United States
| |
Collapse
|
7
|
Grunshaw T, Wood SH, Sproules S, Parrott A, Nordon A, Shapland PDP, Wheelhouse KMP, Tomkinson NCO. A Mechanistic Investigation of the N-Hydroxyphthalimide Catalyzed Benzylic Oxidation Mediated by Sodium Chlorite. J Org Chem 2024; 89:7933-7945. [PMID: 38748510 PMCID: PMC11165572 DOI: 10.1021/acs.joc.4c00583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 05/02/2024] [Accepted: 05/06/2024] [Indexed: 06/13/2024]
Abstract
A detailed investigation into the mechanistic course of N-hydroxyphthalimide catalyzed oxidation of benzylic centers using sodium chlorite as the stoichiometric oxidant is reported. Through a combination of experimental, spectroscopic, and computational techniques, the transformation is interrogated, providing improved reaction conditions and an enhanced understanding of the mechanism. Performing the transformation in the presence of acetic acid or a pH 4.5 buffer leads to extended reaction times but improves the catalyst lifetime, leading to the complete consumption of the starting material. Chlorine dioxide is identified as the active oxidant that is able to oxidize the N-hydroxyphthalimide anion to the phthalimide-N-oxyl radical, the proposed catalytically active species, which is able to abstract a hydrogen atom from the substrate. A second molecule of chlorine dioxide reacts with the resultant radical and, after loss of hypochlorous acid, leads to the observed product. Through a broad variety of techniques including UV/vis, EPR and Raman spectroscopy, isotopic labeling, and the use of radical traps, evidence for the mechanism is presented that is supported through electronic structural calculations.
Collapse
Affiliation(s)
- Thomas Grunshaw
- Department
Pure and Applied Chemistry, Thomas Graham Building, University of Strathclyde, Glasgow G1 1XL, U.K.
- GlaxoSmithKline
R&D, Gunnels Wood
Road, Stevenage SG1 2NY, U.K.
| | - Susanna H. Wood
- Department
Pure and Applied Chemistry, Thomas Graham Building, University of Strathclyde, Glasgow G1 1XL, U.K.
| | - Stephen Sproules
- School
of Chemistry, University of Glasgow, Glasgow G12 8QQ, U.K.
| | - Andrew Parrott
- Department
Pure and Applied Chemistry, Thomas Graham Building, University of Strathclyde, Glasgow G1 1XL, U.K.
| | - Alison Nordon
- Department
Pure and Applied Chemistry, Thomas Graham Building, University of Strathclyde, Glasgow G1 1XL, U.K.
| | | | | | - Nicholas C. O. Tomkinson
- Department
Pure and Applied Chemistry, Thomas Graham Building, University of Strathclyde, Glasgow G1 1XL, U.K.
| |
Collapse
|
8
|
Piedra HF, Plaza M. Advancements in visible-light-induced reactions via alkenyl radical intermediates. Photochem Photobiol Sci 2024; 23:1217-1228. [PMID: 38700648 DOI: 10.1007/s43630-024-00580-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 04/15/2024] [Indexed: 06/18/2024]
Abstract
In recent years, visible-light-induced organic transformations have taken a central role driving forward the progress of modern organic synthesis. These processes typically involve the transient generation of highly reactive radical intermediates, facilitating a diverse array of chemical reactions. Despite the abundance of synthetic strategies enabling the access of aryl and alkyl-centered radicals, the exploitation of photochemistry to generate highly reactive alkenyl radicals has remained notably underdeveloped. In this review, we present recent advancements in visible-light-induced transformations that proceed through the generation of alkenyl radicals from alkenyl-containing precursors, predominantly alkenyl halides, showcasing their application in various organic transformations.
Collapse
Affiliation(s)
- Helena F Piedra
- Departamento de Química Orgánica e Inorgánica and Instituto Universitario de Química Organometálica "Enrique Moles" and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Oviedo, Julián Clavería, 8, 33006, Oviedo, Spain
| | - Manuel Plaza
- Departamento de Química Orgánica e Inorgánica and Instituto Universitario de Química Organometálica "Enrique Moles" and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Oviedo, Julián Clavería, 8, 33006, Oviedo, Spain.
| |
Collapse
|
9
|
Liu K, Lei M, Li X, Zhang X, Zhang Y, Fan W, Li MB, Zhang S. Paired electrocatalysis unlocks cross-dehydrogenative coupling of C(sp 3)-H bonds using a pentacoordinated cobalt-salen catalyst. Nat Commun 2024; 15:2897. [PMID: 38575564 PMCID: PMC10995126 DOI: 10.1038/s41467-024-47220-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Accepted: 03/25/2024] [Indexed: 04/06/2024] Open
Abstract
Cross-dehydrogenative coupling of C(sp3)-H bonds is an ideal approach for C(sp3)-C(sp3) bond construction. However, conventional approaches mainly rely on a single activation mode by either stoichiometric oxidants or electrochemical oxidation, which would lead to inferior selectivity in the reaction between similar C(sp3)-H bonds. Herein we describe our development of a paired electrocatalysis strategy to access an unconventional selectivity in the cross-dehydrogenative coupling of alcoholic α C(sp3)-H with allylic (or benzylic) C-H bonds, which combines hydrogen evolution reaction catalysis with hydride transfer catalysis. To maximize the synergistic effect of the catalyst combinations, a HER catalyst pentacoordinated Co-salen is disclosed. The catalyst displays a large redox-potential gap (1.98 V) and suitable redox potential. With the optimized catalyst combination, an electrochemical cross-dehydrogenative coupling protocol features unconventional chemoselectivity (C-C vs. C-O coupling), excellent functional group tolerance (84 examples), valuable byproduct (hydrogen), and high regio- and site-selectivity. A plausible reaction mechanism is also proposed to rationalize the experimental observations.
Collapse
Affiliation(s)
- Ke Liu
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China
| | - Mengna Lei
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China
| | - Xin Li
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China
| | - Xuemei Zhang
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China
| | - Ying Zhang
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China
| | - Weigang Fan
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China
| | - Man-Bo Li
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China.
| | - Sheng Zhang
- Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei, 230601, Anhui, China.
| |
Collapse
|
10
|
Kato T, Hagiwara K, Inoue M. Generation and Coupling of Radical Species from α-Alkoxy Bridgehead Carboxylic Acid, Selenide, Telluride, Acyl Selenide, and Acyl Telluride. Chem Pharm Bull (Tokyo) 2024; 72:767-771. [PMID: 39198181 DOI: 10.1248/cpb.c24-00441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2024]
Abstract
α-Alkoxy bridgehead radicals enable intermolecular construction of sterically congested C-C bonds due to their sterically accessible nature. We implemented these radical species into total syntheses of various densely oxygenated natural products and demonstrated their exceptional versatility. Herein, we employed different precursors to generate the same α-alkoxy bridgehead radical and compared the efficacy of the precursors for coupling reactions. Specifically, the bridgehead radical of the trioxaadamantane structure was formed from α-alkoxy carboxylic acid, selenide/telluride, and acyl selenide/acyl telluride, and reacted with 4-((tert-butyldimethylsilyl)oxy)cyclopent-2-en-1-one and 5-oxo-1-cyclopentene-1-carbonitrile. The efficiency of the bridgehead radical formation and subsequent coupling reaction significantly depended on the structures of the precursors and acceptors as well as the reaction conditions. Our findings provide new insights for selecting the appropriate substrates of key coupling reactions in the total synthesis of complex natural products.
Collapse
Affiliation(s)
- Takehiro Kato
- Graduate School of Pharmaceutical Sciences, The University of Tokyo
| | - Koichi Hagiwara
- Graduate School of Pharmaceutical Sciences, The University of Tokyo
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo
| |
Collapse
|
11
|
Bhavyesh D, Soliya S, Konakanchi R, Begari E, Ashalu KC, Naveen T. The Recent Advances in Iron-Catalyzed C(sp 3 )-H Functionalization. Chem Asian J 2023:e202301056. [PMID: 38149480 DOI: 10.1002/asia.202301056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 12/21/2023] [Accepted: 12/22/2023] [Indexed: 12/28/2023]
Abstract
The use of iron as a core metal in catalysis has become a research topic of interest over the last few decades. The reasons are clear. Iron is the most abundant transition metal on Earth's crust and it is widely distributed across the world. It has been extracted and processed since the dawn of civilization. All these features render iron a noncontaminant, biocompatible, nontoxic, and inexpensive metal and therefore it constitutes the perfect candidate to replace noble metals (rhodium, palladium, platinum, iridium, etc.). Moreover, direct C-H functionalization is one of the most efficient strategies by which to introduce new functional groups into small organic molecules. The majority of organic compounds contain C(sp3 )-H bonds. Given the enormous importance of organic molecules in so many aspects of existence, the utilization and bioactivity of C(sp3 )-H bonds are of the utmost importance. This review sheds light on the substrate scope, selectivity, benefits, and limitations of iron catalysts for direct C(sp3 )-H bond activations. An overview of the use of iron catalysis in C(sp3 )-H activation protocols is summarized herein up to 2022.
Collapse
Affiliation(s)
- Desai Bhavyesh
- Department of Chemistry, Sardar Vallabhbhai National Institute of Technology Surat, Gujarat, 395 007, India
| | - Sudha Soliya
- Department of Chemistry, Sardar Vallabhbhai National Institute of Technology Surat, Gujarat, 395 007, India
| | - Ramaiah Konakanchi
- Department of Chemistry, VNR Vignana Jyoti Institute of Engineering and Technology, Hyderabad, 500090, India
| | - Eeshwaraiah Begari
- School of Applied Material Sciences, Central University of Gujarat, Gandhinagar, 382030, India
| | - Kashamalla Chinna Ashalu
- Department of Chemistry, School of Science, Indrashil University, Rajpur, Kadi, Gujarat, 382715, India
| | - Togati Naveen
- Department of Chemistry, Sardar Vallabhbhai National Institute of Technology Surat, Gujarat, 395 007, India
| |
Collapse
|
12
|
Watanabe Y, Sakata K, Urabe D, Hagiwara K, Inoue M. Formal Total Synthesis of Batrachotoxin Enabled by Radical and Weix Coupling Reactions. J Org Chem 2023. [PMID: 38051654 DOI: 10.1021/acs.joc.3c02290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Batrachotoxin (1), originally isolated from a Columbian poison-dart frog, is a steroidal alkaloid. Its 6/6/6/5-membered carbocycle (ABCD-ring) contains two double bonds, one nitrogen, and five oxygen functionalities. We developed a radical-based convergent strategy and realized the total synthesis of 1 in 28 steps. The AB-ring and D-ring fragments were efficiently synthesized and linked by exploiting a powerful Et3B/O2-mediated radical coupling reaction. Vinyl triflate and vinyl bromide were then utilized for a Pd/Ni-promoted Weix coupling reaction to cyclize the C-ring. A hydroxy group of the C-ring was stereoselectively installed by a decarboxylative hydroxylation reaction to prepare an advanced intermediate of our previous total synthesis of 1.
Collapse
Affiliation(s)
- Yuuki Watanabe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Komei Sakata
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Daisuke Urabe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Koichi Hagiwara
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| |
Collapse
|
13
|
Watanabe T, Oga K, Matoba H, Nagatomo M, Inoue M. Total Synthesis of Taxol Enabled by Intermolecular Radical Coupling and Pd-Catalyzed Cyclization. J Am Chem Soc 2023; 145:25894-25902. [PMID: 37972241 DOI: 10.1021/jacs.3c10658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
Taxol (1) is a clinically used antineoplastic diterpenoid. The tetracyclic ring system comprises a 6/8/6-membered carbocycle (ABC-ring) and a fused oxetane ring (D-ring) embedded with a bridgehead double bond and decorated with multiple oxygen functionalities. Here, we report a convergent total synthesis of this exceedingly complex natural product. The C-ring fragment was designed to possess a bromocyclohexenone and an extra tetrahydrofuran ring to control the reactivity and selectivity, as well as to minimize functional group manipulations en route to 1. The α-alkoxyacyl telluride of the A-ring served as a radical precursor, and intermolecular radical coupling with the C-ring realized the installation of the C2- and C3-stereocenters and reductive removal of the bromide. After the C8-quaternary stereocenter was constructed by exploiting the three-dimensional shape of the intermediate, the C11-vinyl triflate of A-ring and the C8-methyl ketone of C-ring were utilized for Pd(0)-catalyzed cyclization of the central eight-membered B-ring with the bridgehead olefin. Adjustment of the oxidation level and attachment of the oxetane D-ring completed the total synthesis of 1 (28 steps, as the longest linear sequence). The fragment design principle and implementation of the powerful radical coupling reaction described in the present synthesis provide valuable information for planning and executing syntheses of diverse densely oxygenated terpenoids.
Collapse
Affiliation(s)
- Takahiro Watanabe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo113-0033, Japan
| | - Kyohei Oga
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo113-0033, Japan
| | - Hiroaki Matoba
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo113-0033, Japan
| | - Masanori Nagatomo
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo113-0033, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo113-0033, Japan
| |
Collapse
|
14
|
Xiang S, Ni Q, Liu Q, Zhou S, Wang H, Zhou Y, Liu Y. Approach to Access Benzo[ j]phenanthridinones from 1,7-Enynes and Aryldiazonium Salts via a Domino Radical Relay Process Enabled by a P/N-Heteroleptic Cu(I)-Photosensitizer. J Org Chem 2023; 88:13248-13261. [PMID: 37616100 DOI: 10.1021/acs.joc.3c01509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Abstract
A mild approach for the synthesis of benzo[j]phenanthridin-6(5H)-one derivatives from 1,7-enynes and aryldiazonium salts has been successfully developed involving a domino radical relay process enabled by a heteroleptic Cu(I)-photosensitizer under visible-light-driven photocatalytic conditions. Mechanistic studies disclosed that the oxidative quenching of the excited state of PS 4 with aryldiazonium salts via an SET process generated aryl radicals, which could play a radical initiator-terminator dual role within the whole radical relay process, namely, at the initial step acting as a radical donor to trigger the radical addition to the olefin moieties of 1,7-enynes while at the final stage serving as a radical acceptor to complete the cyclization.
Collapse
Affiliation(s)
- Siwei Xiang
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Qibo Ni
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Qian Liu
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Sicheng Zhou
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Huihui Wang
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Yan Zhou
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Yunkui Liu
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
- Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, Hangzhou 311121, China
| |
Collapse
|
15
|
Heuer A, Coste SC, Singh G, Mercado BQ, Mayer JM. A Guide to Tris(4-Substituted)-triphenylmethyl Radicals. J Org Chem 2023; 88:9893-9901. [PMID: 37403939 PMCID: PMC10367072 DOI: 10.1021/acs.joc.3c00658] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Indexed: 07/06/2023]
Abstract
Triphenylmethyl (trityl, Ph3C•) radicals have been considered the prototypical carbon-centered radical since their discovery in 1900. Tris(4-substituted)-trityls [(4-R-Ph)3C•] have since been used in many ways due to their stability, persistence, and spectroscopic activity. Despite their widespread use, existing synthetic routes toward tris(4-substituted)-trityl radicals are not reproducible and often lead to impure materials. We report here robust syntheses of six electronically varied (4-RPh)3C•, where R = NMe2, OCH3, tBu, Ph, Cl, and CF3. The characterization reported for the radicals and related compounds includes five X-ray crystal structures, electrochemical potentials, and optical spectra. Each radical is best accessed using a stepwise approach from the trityl halide, (RPh)3CCl or (RPh)3CBr, by controllably removing the halide with subsequent 1e- reduction of the trityl cation, (RPh)3C+. These syntheses afford consistently crystalline trityl radicals of high purity for further studies.
Collapse
Affiliation(s)
| | | | - Gurjot Singh
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Brandon Q. Mercado
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - James M. Mayer
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| |
Collapse
|
16
|
Piedra HF, Valdés C, Plaza M. Shining light on halogen-bonding complexes: a catalyst-free activation mode of carbon-halogen bonds for the generation of carbon-centered radicals. Chem Sci 2023; 14:5545-5568. [PMID: 37265729 PMCID: PMC10231334 DOI: 10.1039/d3sc01724a] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 05/03/2023] [Indexed: 06/03/2023] Open
Abstract
The discovery of new activation modes for the creation of carbon-centered radicals is a task of great interest in organic chemistry. Classical activation modes for the generation of highly reactive radical carbon-centered intermediates typically relied on thermal activation of radical initiators or irradiation with unsafe energetic UV light of adequate reaction precursors. In recent years, photoredox chemistry has emerged as a leading strategy towards the catalytic generation of C-centered radicals, which enabled their participation in novel synthetic organic transformations which is otherwise very challenging or even impossible to take place. As an alternative to these activation modes for the generation of C-centered radicals, the pursuit of greener, visible-light initiated reactions that do not necessitate a photoredox/metal catalyst has recently caught the attention of chemists. In this review, we covered recent transformations, which rely on photoactivation with low-energy light of a class of EDA complexes, known as halogen-bonding adducts, for the creation of C-centered radicals.
Collapse
Affiliation(s)
- Helena F Piedra
- Departamento de Química Orgánica e Inorgánica, Instituto Universitario de Química Organometálica "Enrique Moles" and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Oviedo Julián Clavería 8 33006 Oviedo Spain
| | - Carlos Valdés
- Departamento de Química Orgánica e Inorgánica, Instituto Universitario de Química Organometálica "Enrique Moles" and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Oviedo Julián Clavería 8 33006 Oviedo Spain
| | - Manuel Plaza
- Departamento de Química Orgánica e Inorgánica, Instituto Universitario de Química Organometálica "Enrique Moles" and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Universidad de Oviedo Julián Clavería 8 33006 Oviedo Spain
| |
Collapse
|
17
|
Liu FL, Mei L, Wang LT, Zhou Y, Tang K, Li T, Yi R, Wei WT. Radical bicyclization of 1,6-enynes with sulfonyl hydrazides by the use of TBAI/TBHP in the aqueous phase. Chem Commun (Camb) 2023; 59:6391-6394. [PMID: 37157973 DOI: 10.1039/d3cc01102j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A novel 5-exo-dig/6-endo-trig bicyclization of 1,6-enynes with sulfonyl hydrazides in the aqueous phase using the cheap and available tetrabutylammonium iodide (TBAI)-tert-butyl hydroperoxide (TBHP) combined system is reported. The resulting reaction of diverse nitrogen- and oxygen-polyheterocycles displays high chemical selectivity, high step-economy, and a moderate substrate scope. Moreover, iodosulfonylation can be realized by modulating the structure of the 1,6-enynes.
Collapse
Affiliation(s)
- Fa-Liang Liu
- School of Materials Science and Chemical Engineering, Institute of Mass Spectrometry, Ningbo University, Ningbo, Zhejiang, 315211, China.
| | - Lan Mei
- School of Materials Science and Chemical Engineering, Institute of Mass Spectrometry, Ningbo University, Ningbo, Zhejiang, 315211, China.
| | - Ling-Tao Wang
- School of Materials Science and Chemical Engineering, Institute of Mass Spectrometry, Ningbo University, Ningbo, Zhejiang, 315211, China.
| | - Yu Zhou
- School of Materials Science and Chemical Engineering, Institute of Mass Spectrometry, Ningbo University, Ningbo, Zhejiang, 315211, China.
| | - Keqi Tang
- School of Materials Science and Chemical Engineering, Institute of Mass Spectrometry, Ningbo University, Ningbo, Zhejiang, 315211, China.
| | - Ting Li
- College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang, Henan, 473061, China.
| | - Rongnan Yi
- Criminal Technology Department, Hunan Police Academy, Changsha, Hunan, 410138, China
| | - Wen-Ting Wei
- School of Materials Science and Chemical Engineering, Institute of Mass Spectrometry, Ningbo University, Ningbo, Zhejiang, 315211, China.
| |
Collapse
|
18
|
Mondal K, Mallik S, Sardana S, Baidya M. A Visible-Light-Induced α-Aminoalkyl-Radical-Mediated Halogen-Atom Transfer Process: Modular Synthesis of Phenanthridinone Alkaloids. Org Lett 2023; 25:1689-1694. [PMID: 36867403 DOI: 10.1021/acs.orglett.3c00358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
A halogen-atom transfer (XAT) strategy utilizing α-aminoalkyl radicals allows the generation of aryl radicals at room temperature, which is applied for intramolecular cyclization reactions en route to biologically relevant alkaloids. Starting from simple halogen-substituted benzamides under visible light irradiation in the presence of an organophotocatalyst (4CzIPN) and nBu3N allows the modular construction of the phenanthridinone core, which gives facile access to drug analogs and alkaloids, e.g., from the Amaryllidaceae family. The reaction pathway most likely involves a quantum mechanical tunneling enabled transfer event to achieve aromatization-halogen-atom transfer.
Collapse
Affiliation(s)
- Karunamayee Mondal
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, Tamil Nadu, India
| | - Sumitava Mallik
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, Tamil Nadu, India
| | - Sunaina Sardana
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, Tamil Nadu, India
| | - Mahiuddin Baidya
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, Tamil Nadu, India
| |
Collapse
|
19
|
Imamura Y, Takaoka K, Komori Y, Nagatomo M, Inoue M. Total Synthesis of Taxol Enabled by Inter- and Intramolecular Radical Coupling Reactions. Angew Chem Int Ed Engl 2023; 62:e202219114. [PMID: 36646637 DOI: 10.1002/anie.202219114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 01/14/2023] [Accepted: 01/16/2023] [Indexed: 01/18/2023]
Abstract
Taxol is a clinically used drug for the treatment of various types of cancers. Its 6/8/6/4-membered ring (ABCD-ring) system is substituted by eight oxygen functional groups and flanked by four acyl groups, including a β-amino acid side chain. Here we report a 34-step total synthesis of this unusually oxygenated and intricately fused structure. Inter- and intramolecular radical coupling reactions connected the A- and C-ring fragments and cyclized the B-ring, respectively. Functional groups of the A- and C-rings were then efficiently decorated by employing newly developed chemo-, regio-, and stereoselective reactions. Finally, construction of the D-ring and conjugation with the β-amino acid delivered taxol. The powerful coupling reactions and functional group manipulations implemented in the present synthesis provide new valuable information for designing multistep target-oriented syntheses of diverse bioactive natural products.
Collapse
Affiliation(s)
- Yusuke Imamura
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Kyohei Takaoka
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yuma Komori
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Masanori Nagatomo
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| |
Collapse
|
20
|
Paul S, Filippini D, Silvi M. Polarity Transduction Enables the Formal Electronically Mismatched Radical Addition to Alkenes. J Am Chem Soc 2023; 145:2773-2778. [PMID: 36718934 PMCID: PMC9912259 DOI: 10.1021/jacs.2c12699] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Indexed: 02/01/2023]
Abstract
The formation of carbon-carbon bonds via the intermolecular addition of alkyl radicals to alkenes is a cornerstone of organic chemistry and plays a central role in synthesis. However, unless specific electrophilic radicals are involved, polarity matching requirements restrict the alkene component to be electron deficient. This limits the scope of a fundamentally important carbon-carbon bond forming process that could otherwise be more universally applied. Herein, we introduce a polarity transduction strategy that formally overcomes this electronic limitation. Vinyl sulfonium ions are demonstrated to react with carbon-centered radicals, giving adducts that undergo in situ or sequential nucleophilic displacement to provide products that would be inaccessible via traditional methods. The broad generality of this strategy is demonstrated through the derivatization of unmodified complex bioactive molecules.
Collapse
|
21
|
Li H, Li S, Hu H, Sun R, Liu M, Ding A, Liu X, Luo W, Fu Z, Guo S, Cai H. Visible-light-induced C(sp 3)-C(sp 3) bond formation via radical/radical cross-coupling. Chem Commun (Camb) 2023; 59:1205-1208. [PMID: 36629273 DOI: 10.1039/d2cc05840e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Radical/radical cross-coupling remains challenging due to diffusion control issues. Herein, we report a visible-light-induced radical/radical cross-coupling reaction of quaternary ammonium salts and Hantzschs via C-N and C-C bond cleavage. The current synthetic approach furnishes 1,2-diphenylethanes in moderate to good yields and provides a method for the construction of the C(sp3)-C(sp3) bond.
Collapse
Affiliation(s)
- Haoyuan Li
- Department of Chemistry, Nanchang University, No. 999, Xuefu Rd, Nanchang, 330031, P. R. China.
| | - Sen Li
- Department of Chemistry, Nanchang University, No. 999, Xuefu Rd, Nanchang, 330031, P. R. China.
| | - Huimin Hu
- Department of Chemistry, Nanchang University, No. 999, Xuefu Rd, Nanchang, 330031, P. R. China.
| | - Runbo Sun
- Department of Chemistry, Nanchang University, No. 999, Xuefu Rd, Nanchang, 330031, P. R. China.
| | - Meixia Liu
- Department of Chemistry, Nanchang University, No. 999, Xuefu Rd, Nanchang, 330031, P. R. China.
| | - Anjun Ding
- Department of Chemistry, Nanchang University, No. 999, Xuefu Rd, Nanchang, 330031, P. R. China.
| | - Xiaoyong Liu
- Department of Chemistry, Nanchang University, No. 999, Xuefu Rd, Nanchang, 330031, P. R. China.
| | - Wenlin Luo
- Department of Chemistry, Nanchang University, No. 999, Xuefu Rd, Nanchang, 330031, P. R. China.
| | - Zhengjiang Fu
- Department of Chemistry, Nanchang University, No. 999, Xuefu Rd, Nanchang, 330031, P. R. China.
| | - Shengmei Guo
- Department of Chemistry, Nanchang University, No. 999, Xuefu Rd, Nanchang, 330031, P. R. China.
| | - Hu Cai
- Department of Chemistry, Nanchang University, No. 999, Xuefu Rd, Nanchang, 330031, P. R. China.
| |
Collapse
|
22
|
Shimakawa T, Nakamura S, Asai H, Hagiwara K, Inoue M. Total Synthesis of Puberuline C. J Am Chem Soc 2023; 145:600-609. [PMID: 36538394 DOI: 10.1021/jacs.2c11259] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Puberuline C (1) is an architecturally complex C19-diterpenoid alkaloid with a unique ring fusion pattern. The 6/7/5/6/6/6-membered rings (ABCDEF-rings) contain one tertiary amine and six oxygen functionalities, and possess 12 contiguously aligned stereocenters, three of which are quaternary. These structural features of 1 make its chemical construction exceptionally challenging. Here, we disclose the first total synthesis of 1. The synthesis was accomplished from 2-cyclohexenone (9) by integrating radical cascade and Mukaiyama aldol reactions as the key transformations. A double Mannich reaction fused the A- and E-rings, and Sonogashira coupling attached the C-ring, efficiently leading to ACE-rings with the requisite 19 carbons of 1. The chemically stable tertiary chloride of the ACE-ring structure was then transformed to the corresponding bridgehead radical, which participated in the simultaneous cyclization of the B- and F-rings via a highly organized radical cascade process. This unusual step installed five contiguous stereocenters, including two quaternary carbons, without damaging the preexisting multiple polar functionalities. Subsequently, the intramolecular Mukaiyama aldol reaction between silyl enol ether and acetal was realized by applying a combination of SnCl4 and ZnCl2, forging the last remaining D-ring of the hexacycle. Finally, 3 was elaborated into 1 through regio- and stereoselective functionalizations of the BCD-rings. Our novel radical-based strategy achieved the total synthesis of 1 in 32 total steps from simple 9, demonstrating the power of the radical cascade reaction to streamline the assembly of highly complex molecules.
Collapse
Affiliation(s)
- Tsukasa Shimakawa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo113-0033, Japan
| | - Shu Nakamura
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo113-0033, Japan
| | - Hibiki Asai
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo113-0033, Japan
| | - Koichi Hagiwara
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo113-0033, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo113-0033, Japan
| |
Collapse
|
23
|
Ji CL, Han J, Li T, Zhao CG, Zhu C, Xie J. Photoinduced gold-catalyzed divergent dechloroalkylation of gem-dichloroalkanes. Nat Catal 2022. [DOI: 10.1038/s41929-022-00881-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
24
|
Chen L, Li Y, Han M, Peng Y, Chen X, Xiang S, Gao H, Lu T, Luo SP, Zhou B, Wu H, Yang YF, Liu Y. P/ N-Heteroleptic Cu(I)-Photosensitizer-Catalyzed [3 + 2] Regiospecific Annulation of Aminocyclopropanes and Functionalized Alkynes. J Org Chem 2022; 87:15571-15581. [PMID: 36322051 DOI: 10.1021/acs.joc.2c02138] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We report here a regiospecific [3 + 2] annulation between aminocyclopropanes and various functionalized alkynes enabled by a P/N-heteroleptic Cu(I) photosensitizer under photoredox catalysis conditions. Thus, a divergent construction of 3-aminocyclopentene derivatives including methylsulfonyl-, arylsulfonyl-, chloro-, ester-, and trifluoromethyl-functionalized aminocyclopentenes could be achieved with advantages of high regioselectivity, broad substrate compatibility, and mild and environmentally benign reaction conditions.
Collapse
Affiliation(s)
- Lailin Chen
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Ya Li
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Mingfeng Han
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Yun Peng
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Xiahe Chen
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Siwei Xiang
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Hong Gao
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Tianhao Lu
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Shu-Ping Luo
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Bingwei Zhou
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Huayue Wu
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325027, People's Republic of China
| | - Yun-Fang Yang
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Yunkui Liu
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| |
Collapse
|
25
|
Wang L, Chen Z, Fan G, Liu X, Liu P. Organophotoredox and Hydrogen Atom Transfer Cocatalyzed C-H Alkylation of Quinoxalin-2(1 H)-ones with Aldehydes, Amides, Alcohols, Ethers, or Cycloalkanes. J Org Chem 2022; 87:14580-14587. [PMID: 36206555 DOI: 10.1021/acs.joc.2c01967] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Described is a mild method that merges organophotoredox catalysis with hydrogen atom transfer to enable C-H alkylation of quinoxalin-2(1H)-ones with feedstock aldehydes, amides, alcohols, ethers, or cycloalkanes. This reaction occurred under environmentally benign and external oxidant-free reaction conditions, providing a general and sustainable access to various C3-alkylated quinoxalinone derivatives with broad substituent diversity and good functional group compatibility.
Collapse
Affiliation(s)
- Liling Wang
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi 563000, China
| | - Zhaoxing Chen
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi 563000, China
| | - Guohua Fan
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi 563000, China
| | - Xiaozu Liu
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi 563000, China.,Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi 563000, China
| | - Peijun Liu
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Generic Drug Research Center of Guizhou Province, School of Pharmacy, Zunyi Medical University, Zunyi 563000, China.,Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi 563000, China
| |
Collapse
|
26
|
Luguera Ruiz A, La Mantia M, Merli D, Protti S, Fagnoni M. Alkyl Radical Generation via C–C Bond Cleavage in 2-Substituted Oxazolidines. ACS Catal 2022; 12:12469-12476. [PMID: 36249874 PMCID: PMC9552967 DOI: 10.1021/acscatal.2c03768] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/21/2022] [Indexed: 11/30/2022]
Abstract
![]()
There is an urgent need to develop uncharged radical
precursors
to be activated under mild photocatalyzed conditions. 2-Substituted-1,3-oxazolidines
(Eox < 1.3 V vs SCE, smoothly prepared
from the corresponding aldehydes) have been herein employed for the
successful release of tertiary, α-oxy, and α-amido radicals
under photo-organo redox catalysis. The reaction relies on the unprecedented
C–C cleavage occurring from the radical cation of these heterocyclic
derivatives. Such a protocol is applied to the visible-light-driven
conjugate radical addition onto Michael acceptors and vinyl (hetero)arenes
under mild metal-free conditions.
Collapse
Affiliation(s)
- Adrián Luguera Ruiz
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Marta La Mantia
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Daniele Merli
- Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Stefano Protti
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| | - Maurizio Fagnoni
- PhotoGreen Lab, Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy
| |
Collapse
|
27
|
Constantin T, Górski B, Tilby MJ, Chelli S, Juliá F, Llaveria J, Gillen KJ, Zipse H, Lakhdar S, Leonori D. Halogen-atom and group transfer reactivity enabled by hydrogen tunneling. Science 2022; 377:1323-1328. [DOI: 10.1126/science.abq8663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The generation of carbon radicals by halogen-atom and group transfer reactions is generally achieved using tin and silicon reagents that maximize the interplay of enthalpic (thermodynamic) and polar (kinetic) effects. In this work, we demonstrate a distinct reactivity mode enabled by quantum mechanical tunneling that uses the cyclohexadiene derivative γ-terpinene as the abstractor under mild photochemical conditions. This protocol activates alkyl and aryl halides as well as several alcohol and thiol derivatives. Experimental and computational studies unveiled a noncanonical pathway whereby a cyclohexadienyl radical undergoes concerted aromatization and halogen-atom or group abstraction through the reactivity of an effective H atom. This activation mechanism is seemingly thermodynamically and kinetically unfavorable but is rendered feasible through quantum tunneling.
Collapse
Affiliation(s)
| | - Bartosz Górski
- Department of Chemistry, University of Manchester, Manchester M13 9PL, UK
| | - Michael J. Tilby
- Department of Chemistry, University of Manchester, Manchester M13 9PL, UK
| | - Saloua Chelli
- CNRS/Université Toulouse III—Paul Sabatier, Laboratoire Hétérochimie Fondamentale et Appliquée, LHFA UMR 5069, 31062 Toulouse Cedex 09, France
| | - Fabio Juliá
- Department of Chemistry, University of Manchester, Manchester M13 9PL, UK
| | - Josep Llaveria
- Global Discovery Chemistry, Therapeutics Discovery, Janssen Research & Development, Janssen-Cilag S.A., 45007 Toledo, Spain
| | - Kevin J. Gillen
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage SG1 2FX, UK
| | - Hendrik Zipse
- Department Chemie, LMU München, D-81377 München, Germany
| | - Sami Lakhdar
- CNRS/Université Toulouse III—Paul Sabatier, Laboratoire Hétérochimie Fondamentale et Appliquée, LHFA UMR 5069, 31062 Toulouse Cedex 09, France
| | - Daniele Leonori
- Institute of Organic Chemistry, RWTH Aachen University, 52056 Aachen, Germany
| |
Collapse
|
28
|
Radical 4-exo cyclization of bicyclo[2.2.2]octene derivatives: Construction of tricyclo[3.3.1.02,7]nonane skeleton. Tetrahedron Lett 2022. [DOI: 10.1016/j.tetlet.2022.154056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
29
|
|
30
|
Bajya KR, Sermadurai S. Dual Photoredox and Cobalt Catalysis Enabled Transformations. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
| | - Selvakumar Sermadurai
- Indian Institute of Technology Indore Chemistry Khandwa road Simrol 453552 Indore INDIA
| |
Collapse
|
31
|
Tharra PR, Mikhaylov AA, Švejkar J, Gysin M, Hobbie SN, Švenda J. Short Synthesis of (+)‐Actinobolin: Simple Entry to Complex Small‐Molecule Inhibitors of Protein Synthesis. Angew Chem Int Ed Engl 2022; 61:e202116520. [DOI: 10.1002/anie.202116520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Indexed: 01/19/2023]
Affiliation(s)
- Prabhakara R. Tharra
- Department of Chemistry Faculty of Science Masaryk University Kamenice 5 Brno 625 00 Czech Republic
- International Clinical Research Center St. Anne's University Hospital Pekařská 53 Brno 656 91 Czech Republic
| | - Andrey A. Mikhaylov
- Department of Chemistry Faculty of Science Masaryk University Kamenice 5 Brno 625 00 Czech Republic
- International Clinical Research Center St. Anne's University Hospital Pekařská 53 Brno 656 91 Czech Republic
| | - Jiří Švejkar
- Department of Chemistry Faculty of Science Masaryk University Kamenice 5 Brno 625 00 Czech Republic
| | - Marina Gysin
- Institute of Medical Microbiology University of Zürich Gloriastrasse 30 Zürich 8006 Switzerland
| | - Sven N. Hobbie
- Institute of Medical Microbiology University of Zürich Gloriastrasse 30 Zürich 8006 Switzerland
| | - Jakub Švenda
- Department of Chemistry Faculty of Science Masaryk University Kamenice 5 Brno 625 00 Czech Republic
- International Clinical Research Center St. Anne's University Hospital Pekařská 53 Brno 656 91 Czech Republic
| |
Collapse
|
32
|
Kang K, Weix DJ. Nickel-Catalyzed C(sp 3)-C(sp 3) Cross-Electrophile Coupling of In Situ Generated NHP Esters with Unactivated Alkyl Bromides. Org Lett 2022; 24:2853-2857. [PMID: 35416673 PMCID: PMC9126088 DOI: 10.1021/acs.orglett.2c00805] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The formation of C(sp3)-C(sp3) bonds by cross-coupling remains a challenge in synthesis. Here, we demonstrate a two-step, one-pot protocol for the in situ generation of N-hydroxyphthalimide esters and their nickel-catalyzed cross-electrophile coupling with unactivated alkyl bromides for the construction of 1°/1 ° C(sp3)-C(sp3) bonds. The conditions tolerate an array of functional groups, and mechanistic studies indicate that both substrates are converted to alkyl radicals during the reaction.
Collapse
Affiliation(s)
- Kai Kang
- University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| | - Daniel J Weix
- University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
| |
Collapse
|
33
|
Pitre SP. Radical coupling decreases synthetic burden. Science 2022; 375:1234. [PMID: 35298276 DOI: 10.1126/science.abo2398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Cross coupling of light-promoted β-keto radicals enables natural product syntheses.
Collapse
Affiliation(s)
- Spencer P Pitre
- Department of Chemistry, Oklahoma State University, Stillwater, OK 74078, USA
| |
Collapse
|
34
|
Chakrabarty A, Mukherjee S. Iridium-Catalyzed Enantioselective and Chemodivergent Allenylic Alkylation of Vinyl Azides for the Synthesis of α-Allenylic Amides and Ketones. Angew Chem Int Ed Engl 2022; 61:e202115821. [PMID: 35044711 DOI: 10.1002/anie.202115821] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Indexed: 01/14/2023]
Abstract
The first enantioselective synthesis of α-allenylic amides and ketones through allenylic alkylation of vinyl azides is reported. In these chemodivergent reactions, cooperatively catalyzed by a IrI /(phosphoramidite,olefin) complex and Sc(OTf)3 , vinyl azides act as the surrogate for both amide enolates and ketone enolates. The desiccant (molecular sieves) plays a crucial role in controlling the chemodivergency of this enantioconvergent and regioselective reaction: Under otherwise identical reaction conditions, the presence of the desiccant led to α-allenylic amides, while its absence resulted in α-allenylic ketones. Utilizing racemic allenylic alcohols as the alkylating agent, the overall process represents a dynamic kinetic asymmetric transformation (DyKAT), where both the products are formed with the same absolute configuration. To the best of our knowledge, this is the first example of the use of vinyl azide as the ketone enolate surrogate in an enantioselective transformation.
Collapse
Affiliation(s)
- Aditya Chakrabarty
- Department of Organic Chemistry, Indian Institute of Science, Bangalore, 560 012, India
| | - Santanu Mukherjee
- Department of Organic Chemistry, Indian Institute of Science, Bangalore, 560 012, India
| |
Collapse
|
35
|
|
36
|
Tharra PR, Mikhaylov AA, Švejkar J, Gysin M, Hobbie SN, Švenda J. Short Synthesis of (+)‐Actinobolin: Simple Entry to Complex Small‐Molecule Inhibitors of Protein Synthesis. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202116520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Prabhakara R. Tharra
- Department of Chemistry Faculty of Science Masaryk University Kamenice 5 Brno 625 00 Czech Republic
- International Clinical Research Center St. Anne's University Hospital Pekařská 53 Brno 656 91 Czech Republic
| | - Andrey A. Mikhaylov
- Department of Chemistry Faculty of Science Masaryk University Kamenice 5 Brno 625 00 Czech Republic
- International Clinical Research Center St. Anne's University Hospital Pekařská 53 Brno 656 91 Czech Republic
| | - Jiří Švejkar
- Department of Chemistry Faculty of Science Masaryk University Kamenice 5 Brno 625 00 Czech Republic
| | - Marina Gysin
- Institute of Medical Microbiology University of Zürich Gloriastrasse 30 Zürich 8006 Switzerland
| | - Sven N. Hobbie
- Institute of Medical Microbiology University of Zürich Gloriastrasse 30 Zürich 8006 Switzerland
| | - Jakub Švenda
- Department of Chemistry Faculty of Science Masaryk University Kamenice 5 Brno 625 00 Czech Republic
- International Clinical Research Center St. Anne's University Hospital Pekařská 53 Brno 656 91 Czech Republic
| |
Collapse
|
37
|
Chakrabarty A, Mukherjee S. Iridium‐Catalyzed Enantioselective and Chemodivergent Allenylic Alkylation of Vinyl Azides for the Synthesis of α‐Allenylic Amides and Ketones**. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202115821] [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)
- Aditya Chakrabarty
- Department of Organic Chemistry Indian Institute of Science Bangalore 560 012 India
| | - Santanu Mukherjee
- Department of Organic Chemistry Indian Institute of Science Bangalore 560 012 India
| |
Collapse
|
38
|
Yao Z, Zhang X, Luo Z, Pan Y, Zhao H, Li B, Xu L, Shi Q, Fan Q. Na
2
S
2
O
8
‐Mediated Tandem One‐Pot Construction of 3,3‐Disubsituted 3,4‐Dihydroquinoxalin‐2(1
H
)‐ones with 4‐Alkyl‐1,4‐dihydropyridines as Alkyl Radical Sources. ASIAN J ORG CHEM 2022. [DOI: 10.1002/ajoc.202100609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Zhen Yao
- Department of Chemistry Renmin University of China Beijing 100872 P. R. China
| | - Xin Zhang
- Department of Chemistry Renmin University of China Beijing 100872 P. R. China
| | - Zhenli Luo
- Department of Chemistry Renmin University of China Beijing 100872 P. R. China
| | - Yixiao Pan
- Department of Chemistry Renmin University of China Beijing 100872 P. R. China
| | - Haoqiang Zhao
- Department of Chemistry Renmin University of China Beijing 100872 P. R. China
| | - Bohan Li
- Department of Chemistry Renmin University of China Beijing 100872 P. R. China
| | - Lijin Xu
- Department of Chemistry Renmin University of China Beijing 100872 P. R. China
| | - Qian Shi
- College of Chemistry & Materials Engineering Wenzhou University Wenzhou 325035 P. R. China
| | - Qing‐Hua Fan
- Institute of Chemistry Chinese Academy of Sciences
- University of Chinese Academy of Sciences Beijing 100190 P. R. China
| |
Collapse
|
39
|
Xu SH, Yan DM, Rao L, Jiang M, Wu YL, Xiao WJ, Chen JR. Photocatalytic selective 1,2-hydroxyacylmethylation of 1,3-dienes with sulfur ylides as source of alkyl radicals. Org Chem Front 2022. [DOI: 10.1039/d2qo00383j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Exploration of the zwitterionic property of sulfur ylides has long been known as a flexible strategy in a wide range of chemical transformations for different ring-sized construction. By contrast, their...
Collapse
|
40
|
Zhuo J, Zhu C, Wu J, Li Z, Li C. Reductive Radical Annulation Strategy toward Bicyclo[3.2.1]octanes: Synthesis of ent-Kaurane and Beyerane Diterpenoids. J Am Chem Soc 2021; 144:99-105. [PMID: 34958563 DOI: 10.1021/jacs.1c11623] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Here we report a general [3 + 2] radical annulation that allows the facile construction of bicyclo[3.2.1]octane motifs in ent-kaurane- and beyerane-type diterpenoids. This radical annulation is difficult to control but was realized by harnessing an unprecedented and counterintuitive effect of TEMPO. Eleven natural products with a wide array of oxidation states are easily prepared, demonstrating the powerful utility of this straightforward synthetic strategy.
Collapse
Affiliation(s)
- Junming Zhuo
- Graduate School of Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China.,National Institute of Biological Sciences, Beijing 102206, China
| | - Chunlin Zhu
- Graduate School of Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China.,National Institute of Biological Sciences, Beijing 102206, China
| | - Jinbao Wu
- National Institute of Biological Sciences, Beijing 102206, China
| | - Zijian Li
- National Institute of Biological Sciences, Beijing 102206, China
| | - Chao Li
- Graduate School of Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China.,National Institute of Biological Sciences, Beijing 102206, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 100084, China
| |
Collapse
|
41
|
Kuwana D, Komori Y, Nagatomo M, Inoue M. Photoinduced Decarboxylative Radical Coupling Reaction of Multiply Oxygenated Structures by Catalysis of Pt-Doped TiO 2. J Org Chem 2021; 87:730-736. [PMID: 34936365 DOI: 10.1021/acs.joc.1c02736] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new reaction system was devised for decarboxylative radical coupling reactions by heterogeneous semiconductor photoredox catalysis. When an α-alkoxy carboxylic acid and Pt-doped TiO2 in EtOAc were irradiated with a violet light-emitting diode at room temperature, the photogenerated electron hole of TiO2 oxidatively induced the ejection of CO2 via the formation of a carboxyl radical to produce the corresponding α-alkoxy radical. C(sp3)-C(sp3) bond formation between the radicals led to dimers with reductive conversion of protons to H2 by the photogenerated electron. Alternatively, in the presence of an electron-deficient olefin, an intermolecular radical addition reaction occurred, resulting in the formation of a 1,4-adduct via single-electron reduction and subsequent protonation. These operationally simple and mild transformations are amenable to the one-step assembly of densely oxygenated linear and branched carbon chains.
Collapse
Affiliation(s)
- Daiki Kuwana
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yuma Komori
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masanori Nagatomo
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| |
Collapse
|
42
|
Das S, Mandal T, De Sarkar S. Acridine Orange Hemi(Zinc Chloride) Salt as a Lewis Acid‐Photoredox Hybrid Catalyst for the Generation of
α
‐Carbonyl Radicals. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202101053] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Sanju Das
- Department of Chemical Sciences Indian Institute of Science Education and Research Kolkata Mohanpur 741246 West Bengal India
| | - Tanumoy Mandal
- Department of Chemical Sciences Indian Institute of Science Education and Research Kolkata Mohanpur 741246 West Bengal India
| | - Suman De Sarkar
- Department of Chemical Sciences Indian Institute of Science Education and Research Kolkata Mohanpur 741246 West Bengal India
| |
Collapse
|
43
|
Fujino H, Nagatomo M, Inoue M. Total Syntheses of Hikosamine and Hikizimycin. J Org Chem 2021; 86:16220-16230. [PMID: 34569228 DOI: 10.1021/acs.joc.1c01773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hikizimycin (1) is a potent anthelmintic and antibacterial natural product. The core 4-amino-4-deoxyundecose sugar (hikosamine) of 1 consists of an 11-carbon linear chain substituted with one amino group and 10 hydroxy groups. The C1 and C6O positions of the 10 contiguous stereocenters are further appended by a cytosine base and a 3-amino-3-deoxyglucose sugar (kanosamine), respectively. Since the structural determination in the early 1970s, synthetic chemists have been attracted by this exceedingly complex structure and have investigated the full chemical construction of 1. These synthetic efforts culminated in four syntheses of the protected hikosamines and two total syntheses of 1. In this Perspective, we summarize the strategies and tactics utilized in these syntheses to showcase the evolution of modern natural product synthesis.
Collapse
Affiliation(s)
- Haruka Fujino
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masanori Nagatomo
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| |
Collapse
|
44
|
Filippini D, Silvi M. Visible light-driven conjunctive olefination. Nat Chem 2021; 14:66-70. [PMID: 34737455 DOI: 10.1038/s41557-021-00807-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 09/03/2021] [Indexed: 01/10/2023]
Abstract
Carboxylic acids and aldehydes are ubiquitous in chemistry and are native functionalities in many bioactive molecules and natural products. As such, a general cross-coupling process that involves these partners would open new avenues to achieve molecular diversity. Here we report a visible-light-mediated and transition metal-free conjunctive olefination that uses an alkene 'linchpin' with a defined geometry to cross-couple complex molecular scaffolds that contain carboxylic acids and aldehydes. The chemistry merges two cornerstones of organic synthesis-namely, the Wittig reaction and photoredox catalysis-in a catalytic cycle that couples a radical addition process with the redox generation of a phosphonium ylide. The methodology allows the rapid structural diversification of bioactive molecules and natural products in a native form, with a high functional group tolerance, and also forges a new alkene functional group with a programmable E-Z stereochemistry.
Collapse
Affiliation(s)
- Dario Filippini
- GSK Carbon Neutral Laboratories for Sustainable Chemistry, University of Nottingham, Nottingham, UK.,School of Chemistry, University of Nottingham, Nottingham, UK
| | - Mattia Silvi
- GSK Carbon Neutral Laboratories for Sustainable Chemistry, University of Nottingham, Nottingham, UK. .,School of Chemistry, University of Nottingham, Nottingham, UK.
| |
Collapse
|
45
|
Yu M, Jia X, Lin D, Du X, Jin D, Wei Y, Xie L, Huang W. Stereoisomer-Independent Stable Blue Emission in Axial Chiral Difluorenol. Front Chem 2021; 9:717892. [PMID: 34540799 PMCID: PMC8446198 DOI: 10.3389/fchem.2021.717892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/20/2021] [Indexed: 12/04/2022] Open
Abstract
Bulky conjugated molecules with high stability are the prerequisite for the overall improvement of performance in wide-bandgap semiconductors. Herein, a chiral difluorenol, 2,2′-(9,9′-spirobi[fluorene]-2,2′-diyl)bis(9-(4-(octyloxy)phenyl)-9H-fluoren-9-ol) (DOHSBF), is set as a desirable model to reveal the stereoisomeric effects of wide-bandgap molecules toward controlling photophysical behavior and improving thermal and optical stability. Three diastereomers are obtained and elucidated by NMR spectra. Interestingly, the effect of modifying the stereo-centers is not observed on optical properties in solutions, pristine films, or post-treated film states. All three diastereomers as well as the mixture exhibit excellent spectral stability without undesirable green emission. Therefore, this stereoisomer-independent blue-emitting difluorenol will be a promising candidate for next-generation wide-bandgap semiconductors that would have extensive application in organic photonics.
Collapse
Affiliation(s)
- Mengna Yu
- Center for Molecular Systems and Organic Devices (CMSOD), State Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing, China
| | - Xiong Jia
- Center for Molecular Systems and Organic Devices (CMSOD), State Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing, China
| | - Dongqing Lin
- Center for Molecular Systems and Organic Devices (CMSOD), State Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing, China
| | - Xue Du
- Center for Molecular Systems and Organic Devices (CMSOD), State Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing, China
| | - Dong Jin
- Center for Molecular Systems and Organic Devices (CMSOD), State Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing, China
| | - Ying Wei
- Center for Molecular Systems and Organic Devices (CMSOD), State Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing, China
| | - Linghai Xie
- Center for Molecular Systems and Organic Devices (CMSOD), State Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing, China.,Frontiers Science Center for Flexible Electronics (FSCFE), MIIT Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), Xi'an, China
| | - Wei Huang
- Center for Molecular Systems and Organic Devices (CMSOD), State Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing, China.,Frontiers Science Center for Flexible Electronics (FSCFE), MIIT Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), Xi'an, China
| |
Collapse
|
46
|
Yue F, Dong J, Liu Y, Wang Q. Visible-Light-Mediated C-I Difluoroallylation with an α-Aminoalkyl Radical as a Mediator. Org Lett 2021; 23:7306-7310. [PMID: 34494433 DOI: 10.1021/acs.orglett.1c02905] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Herein, we report a protocol for direct visible-light-mediated C-I difluoroallylation reactions of α-trifluoromethyl arylalkenes with alkyl iodides at room temperature with an α-aminoalkyl radical as a mediator. The protocol permits efficient functionalization of various α-trifluoromethyl arylalkenes with cyclic and acyclic primary, secondary, and tertiary alkyl iodides and is scalable to the gram level. This mild protocol uses an inexpensive mediator and is suitable for late-stage functionalization of complex natural products and drugs.
Collapse
Affiliation(s)
- Fuyang Yue
- State Key Laboratory of Elemento-Organic Chemistry, Research Institute of Elemento-Organic Chemistry, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin 300071, People's Republic of China
| | - Jianyang Dong
- State Key Laboratory of Elemento-Organic Chemistry, Research Institute of Elemento-Organic Chemistry, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin 300071, People's Republic of China
| | - Yuxiu Liu
- State Key Laboratory of Elemento-Organic Chemistry, Research Institute of Elemento-Organic Chemistry, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin 300071, People's Republic of China
| | - Qingmin Wang
- State Key Laboratory of Elemento-Organic Chemistry, Research Institute of Elemento-Organic Chemistry, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin 300071, People's Republic of China
| |
Collapse
|
47
|
Hirose A, Watanabe A, Ogino K, Nagatomo M, Inoue M. Unified Total Syntheses of Rhamnofolane, Tigliane, and Daphnane Diterpenoids. J Am Chem Soc 2021; 143:12387-12396. [PMID: 34319739 DOI: 10.1021/jacs.1c06450] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Rhamnofolane, tigliane, and daphnane diterpenoids are structurally complex natural products with multiple oxygen functionalities, making them synthetically challenging. While these diterpenoids share a 5/7/6-trans-fused ring system (ABC-ring), the three-carbon substitutions at the C13- and C14-positions on the C-ring and appending oxygen functional groups differ among them, accounting for the disparate biological activities of these natural products. Here, we developed a new, unified strategy for expeditious total syntheses of five representative members of these three families, crotophorbolone (1), langduin A (2), prostratin (3), resiniferatoxin (4), and tinyatoxin (5). Retrosynthetically, 1-5 were simplified into their common ABC-ring 6 by detaching the three-carbon units and the oxygen-appended groups. Intermediate 6 with six stereocenters was assembled from four achiral fragments in 12 steps by integrating three powerful transformations, as follows: (i) asymmetric Diels-Alder reaction to induce formation of the C-ring; (ii) π-allyl Stille coupling reaction to set the trisubstituted E-olefin of the B-ring; and (iii) Eu(fod)3-promoted 7-endo cyclization of the B-ring via the generation of a bridgehead radical. Then 6 was diversified into 1-5 by selective installation of the different functional groups. Attachment of the C14-β-isopropenyl and isopropyl groups led to 1 and 2, respectively, while oxidative acetoxylation and C13,14-β-dimethylcyclopropane formation gave rise to 3. Finally, formation of an α-oriented caged orthoester by C13-stereochemical inversion and esterification with two different homovanillic acids delivered 4 and 5 with a C13-β-isopropenyl group. This unified synthetic route to 1-5 required only 16-20 total steps, demonstrating the exceptional efficiency of the present strategy.
Collapse
Affiliation(s)
- Akira Hirose
- Graduate School of Pharmaceutical Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ayumu Watanabe
- Graduate School of Pharmaceutical Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kohei Ogino
- Graduate School of Pharmaceutical Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masanori Nagatomo
- Graduate School of Pharmaceutical Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| |
Collapse
|
48
|
Immel JR, Chilamari M, Bloom S. Combining flavin photocatalysis with parallel synthesis: a general platform to optimize peptides with non-proteinogenic amino acids. Chem Sci 2021; 12:10083-10091. [PMID: 34377401 PMCID: PMC8317666 DOI: 10.1039/d1sc02562g] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 06/28/2021] [Indexed: 02/06/2023] Open
Abstract
Most peptide drugs contain non-proteinogenic amino acids (NPAAs), born out through extensive structure-activity relationship (SAR) studies using solid-phase peptide synthesis (SPPS). Synthetically laborious and expensive to manufacture, NPAAs also can have poor coupling efficiencies allowing only a small fraction to be sampled by conventional SPPS. To gain general access to NPAA-containing peptides, we developed a first-generation platform that merges contemporary flavin photocatalysis with parallel synthesis to simultaneously make, purify, quantify, and even test up to 96 single-NPAA peptide variants via the unique combination of boronic acids and a dehydroalanine residue in a peptide. We showcase the power of our newly minted platform to introduce NPAAs of diverse chemotypes-aliphatic, aromatic, heteroaromatic-directly into peptides, including 15 entirely new residues, and to evolve a simple proteinogenic peptide into an unnatural inhibitor of thrombin by non-classical peptide SAR.
Collapse
Affiliation(s)
- Jacob R Immel
- Department of Medicinal Chemistry, The University of Kansas Integrated Science Building Lawrence KS 66045 USA
| | - Maheshwerreddy Chilamari
- Department of Medicinal Chemistry, The University of Kansas Integrated Science Building Lawrence KS 66045 USA
| | - Steven Bloom
- Department of Medicinal Chemistry, The University of Kansas Integrated Science Building Lawrence KS 66045 USA
| |
Collapse
|
49
|
Silva TS, Coelho F. Methodologies for the synthesis of quaternary carbon centers via hydroalkylation of unactivated olefins: twenty years of advances. Beilstein J Org Chem 2021; 17:1565-1590. [PMID: 34290837 PMCID: PMC8275869 DOI: 10.3762/bjoc.17.112] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 06/21/2021] [Indexed: 01/01/2023] Open
Abstract
Olefin double-bond functionalization has been established as an excellent strategy for the construction of elaborate molecules. In particular, the hydroalkylation of olefins represents a straightforward strategy for the synthesis of new C(sp3)–C(sp3) bonds, with concomitant formation of challenging quaternary carbon centers. In the last 20 years, numerous hydroalkylation methodologies have emerged that have explored the diverse reactivity patterns of the olefin double bond. This review presents examples of olefins acting as electrophilic partners when coordinated with electrophilic transition-metal complexes or, in more recent approaches, when used as precursors of nucleophilic radical species in metal hydride hydrogen atom transfer reactions. This unique reactivity, combined with the wide availability of olefins as starting materials and the success reported in the construction of all-carbon C(sp3) quaternary centers, makes hydroalkylation reactions an ideal platform for the synthesis of molecules with increased molecular complexity.
Collapse
Affiliation(s)
- Thiago S Silva
- Laboratory of Synthesis of Natural Products and Drugs, Department of Organic Chemistry, Chemistry Institute, University of Campinas, PO Box 6154 - 13083-970, Campinas - SP, Brazil
| | - Fernando Coelho
- Laboratory of Synthesis of Natural Products and Drugs, Department of Organic Chemistry, Chemistry Institute, University of Campinas, PO Box 6154 - 13083-970, Campinas - SP, Brazil
| |
Collapse
|
50
|
Escobar RA, Johannes JW. Reductive Radical Conjugate Addition of Alkyl Electrophiles Catalyzed by a Cobalt/Iridium Photoredox System. Org Lett 2021; 23:6046-6051. [PMID: 34270268 DOI: 10.1021/acs.orglett.1c02114] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Alkyl and aryl halides have been studied extensively as radical precursors; however, mild and less toxic conditions for the activation of alkyl bromides toward alkyl radicals are still desirable. Reported here is a reductive radical conjugate addition that allows for the formation of alkyl radicals via activation of alkyl bromides through cobalt/iridium catalysis. The developed conditions are emphasized in the broad substrate scope presented, including benzylic halides and halides containing free alcohols, silanes, and chlorides.
Collapse
Affiliation(s)
- Randolph A Escobar
- Medicinal Chemistry, Research and Early Development, Oncology R&D, AstraZeneca, Waltham, Massachusetts 02451, United States
| | - Jeffrey W Johannes
- Medicinal Chemistry, Research and Early Development, Oncology R&D, AstraZeneca, Waltham, Massachusetts 02451, United States
| |
Collapse
|