1
|
Ho KT, Pierce JG. Synthesis of Spiropyrrolines via One-Pot Tf 2O-Mediated Amide Activation/Formal [3 + 2]-Cycloaddition of α-Formylamino Ketones. J Org Chem 2024; 89:13031-13037. [PMID: 39230008 DOI: 10.1021/acs.joc.4c01128] [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
An efficient method for the synthesis of spiropyrrolines from readily accessible α-formylamino ketones is reported. The method involves amide activation using Tf2O, followed by a formal [3 + 2]-cycloaddition of the resulting enolic nitrilium intermediate with Michael acceptors, ultimately affording spiropyrrolines. Mechanistic insights were gained through NMR studies, elucidating the precise role of the base additive and suggesting the formation of an enolic nitrilium intermediate.
Collapse
Affiliation(s)
- Khanh-Toan Ho
- Department of Chemistry and Integrative Sciences Initiative, NC State University, Raleigh, North Carolina 27695, United States
| | - Joshua G Pierce
- Department of Chemistry and Integrative Sciences Initiative, NC State University, Raleigh, North Carolina 27695, United States
| |
Collapse
|
2
|
Sugiyama Y, Yamada K, Kaneko D, Kusagawa Y, Okamura T, Sato T. Iridium-Catalyzed Reductive (3+2) Annulation of Lactams Enabling the Rapid Total Synthesis of (±)-Eburnamonine. Angew Chem Int Ed Engl 2024; 63:e202317290. [PMID: 38088513 DOI: 10.1002/anie.202317290] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Indexed: 12/30/2023]
Abstract
A reductive (3+2) annulation of lactams through iridium-catalyzed hydrosilylation and photoredox coupling with α-bromoacetic acid was developed. The iridium-catalyzed hydrosilylation of the lactam carbonyl group and subsequent elimination provide a transient cyclic enamine, which undergoes iridium-catalyzed photoredox coupling with α-bromoacetic acid in a one-pot process. The developed conditions show high functional-group tolerance and provide cyclic N,O-acetals containing a quaternary carbon center. The resulting N,O-acetals undergo a variety of acid-mediated nucleophilic addition reactions via iminium ions to give substituted cyclic amines. The developed sequence including reductive (3+2) annulation and acid-mediated nucleophilic addition was successfully applied to the four-step total synthesis of (±)-eburnamonine.
Collapse
Affiliation(s)
- Yasukazu Sugiyama
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - Kento Yamada
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - Daiki Kaneko
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - Yuya Kusagawa
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - Toshitaka Okamura
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - Takaaki Sato
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| |
Collapse
|
3
|
Reddy CR, Theja A, Srinivasu E, Subbarao M. Dearomative ipso-Cyclization to Spiropseudoindoxyls: An Extendable Approach To Access Indolo[3,2- c]quinolinones and Isocryptolepine. Org Lett 2024; 26:68-72. [PMID: 38160428 DOI: 10.1021/acs.orglett.3c03643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
A metal-free oxidative intramolecular dearomative spirocyclization of indole-3-formyl-2-carboxamides has been developed for the first time, affording spiropseudoindoxyls in good yields. This domino process proceeds through sequential oxidation, decarboxylation and ipso-arylation. The unique feature of this approach includes the compatibility of N-protected-indole-2-carboxamides. Further, a hitherto unknown rearrangement of spiropseudoindoxyls to indoloquinolones has been achieved. The synthetic utility of this strategy has also been showcased by the construction of a natural alkaloid, isocryptolepine.
Collapse
Affiliation(s)
- Chada Raji Reddy
- Department of Organic Synthesis & Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Agnuru Theja
- Department of Organic Synthesis & Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Ejjirotu Srinivasu
- Department of Organic Synthesis & Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Muppidi Subbarao
- Department of Organic Synthesis & Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| |
Collapse
|
4
|
Angyal P, Hegedüs K, Mészáros BB, Daru J, Dudás Á, Galambos AR, Essmat N, Al-Khrasani M, Varga S, Soós T. Total Synthesis and Structural Plasticity of Kratom Pseudoindoxyl Metabolites. Angew Chem Int Ed Engl 2023; 62:e202303700. [PMID: 37332089 DOI: 10.1002/anie.202303700] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 06/13/2023] [Accepted: 06/15/2023] [Indexed: 06/20/2023]
Abstract
Mitragynine pseudoindoxyl, a kratom metabolite, has attracted increasing attention due to its favorable side effect profile as compared to conventional opioids. Herein, we describe the first enantioselective and scalable total synthesis of this natural product and its epimeric congener, speciogynine pseudoindoxyl. The characteristic spiro-5-5-6-tricyclic system of these alkaloids was formed through a protecting-group-free cascade relay process in which oxidized tryptamine and secologanin analogues were used. Furthermore, we discovered that mitragynine pseudoindoxyl acts not as a single molecular entity but as a dynamic ensemble of stereoisomers in protic environments; thus, it exhibits structural plasticity in biological systems. Accordingly, these synthetic, structural, and biological studies provide a basis for the planned design of mitragynine pseudoindoxyl analogues, which can guide the development of next-generation analgesics.
Collapse
Affiliation(s)
- Péter Angyal
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
- Hevesy György PhD School of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/A, 1117, Budapest, Hungary
| | - Kristóf Hegedüs
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
- Hevesy György PhD School of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/A, 1117, Budapest, Hungary
| | - Bence Balázs Mészáros
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
| | - János Daru
- Department of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/A, 1117, Budapest, Hungary
| | - Ádám Dudás
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
- Hevesy György PhD School of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/A, 1117, Budapest, Hungary
| | - Anna Rita Galambos
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Nagyvárad tér 4, 1089, Budapest, Hungary
| | - Nariman Essmat
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Nagyvárad tér 4, 1089, Budapest, Hungary
| | - Mahmoud Al-Khrasani
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Nagyvárad tér 4, 1089, Budapest, Hungary
| | - Szilárd Varga
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
| | - Tibor Soós
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
| |
Collapse
|
5
|
Higuchi K, Yamamoto K, Nakamura S, Naruse H, Ito M, Sugiyama S. Preparation of Alkyl Di( p-tolyl)sulfonium Salts and Their Application in Metal-Free C(sp 3)-C(sp 3) and C(sp 3)-C(sp 2) Bond Formations. Org Lett 2023; 25:3766-3771. [PMID: 37167562 DOI: 10.1021/acs.orglett.3c01233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Alkyldiarylsulfonium salts were synthesized by a combination of active sulfonium species, prepared through the activation of diarylsulfoxide, and alkyl nucleophiles. The isolated sulfonium salts were subjected to the allylation and cyclopropanation of the active methylene compounds and metal-free C(sp3)-C(sp2) couplings via oxyallyl cation intermediates under mild conditions. The series of reactions included an umpolung strategy for the coupling of alkyl nucleophiles and metal-free C-C bond formation using sulfonium salts.
Collapse
Affiliation(s)
- Kazuhiro Higuchi
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Kai Yamamoto
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Shunsuke Nakamura
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Haruka Naruse
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Motoki Ito
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Shigeo Sugiyama
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan
| |
Collapse
|
6
|
Xi S, Jiang Y, Yang J, Yang J, Miao D, Chen B, Huang W, He L, Qiu H, Zhang M. Generation and [2,3]-Sigmatropic Rearrangement of Ammonium Ylides from Cyclopropyl Ketones for Chiral Indolizidines with Bridgehead Quaternary Stereocenters. Org Lett 2022; 24:6957-6961. [DOI: 10.1021/acs.orglett.2c02759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Song Xi
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Yan Jiang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Jiaojiao Yang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Jiao Yang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Dingyin Miao
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Baoyi Chen
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Wanqiu Huang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Ling He
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Hanyue Qiu
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
| | - Min Zhang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China
- Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Gannan Medical University, Ganzhou 341000, China
| |
Collapse
|
7
|
Yamamoto Y, Tabuchi A, Hosono K, Ochi T, Yamazaki K, Kodama S, Nomoto A, Ogawa A. A two-phase bromination process using tetraalkylammonium hydroxide for the practical synthesis of α-bromolactones from lactones. Beilstein J Org Chem 2021; 17:2906-2914. [PMID: 34956409 PMCID: PMC8685563 DOI: 10.3762/bjoc.17.198] [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: 09/30/2021] [Accepted: 11/24/2021] [Indexed: 11/23/2022] Open
Abstract
A simple and efficient method for α-brominating lactones that affords α-bromolactones under mild conditions using tetraalkylammonium hydroxide (R4N+OH-) as a base was developed. Lactones are ring-opened with Br2 and a substoichiometric amount of PBr3, leading to good yields of the corresponding α-bromocarboxylic acids. Subsequent intramolecular cyclization over 1 h using a two-phase system (H2O/CHCl3) containing R4N+OH- afforded α-bromo lactones in good yields. This method can be applied at the 10 mmol scale using simple operations. α-Bromo-δ-valerolactone, which is extremely reactive and difficult to isolate, could be isolated and stored in a freezer for about one week using the developed method. Optimizing the solvent for environmentally friendly large-scale syntheses revealed that methyl ethyl ketone (MEK) was as effective. In addition, in situ-generated α-bromo-δ-valerolactone was directly converted into a sulfur-substituted functional lactone without difficulty by reacting it with a sulfur nucleophile in one pot without isolation. This new bromination system is expected to facilitate the industrial use of α-bromolactones as important intermediates.
Collapse
Affiliation(s)
- Yuki Yamamoto
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
| | - Akihiro Tabuchi
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
| | - Kazumi Hosono
- Nippoh Chemicals Co., Ltd. Neo Kawai Building, 8-15,4-Chome, Nihonbashi-Honchou, Chuo-Ku, Tokyo 103-0023, Japan
| | - Takanori Ochi
- Nippoh Chemicals Co., Ltd. Neo Kawai Building, 8-15,4-Chome, Nihonbashi-Honchou, Chuo-Ku, Tokyo 103-0023, Japan
| | - Kento Yamazaki
- Nippoh Chemicals Co., Ltd. Neo Kawai Building, 8-15,4-Chome, Nihonbashi-Honchou, Chuo-Ku, Tokyo 103-0023, Japan
| | - Shintaro Kodama
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
| | - Akihiro Nomoto
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
| | - Akiya Ogawa
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
| |
Collapse
|
8
|
Dhote PS, Patel P, Vanka K, Ramana CV. Total synthesis of the pseudoindoxyl class of natural products. Org Biomol Chem 2021; 19:7970-7994. [PMID: 34486008 DOI: 10.1039/d1ob01285a] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The pseudoindoxyl sub-structural motif, amongst the large set of the indole class of alkaloids, represents a unique subset of the oxygenated indole class of the alkaloid family. A majority of this class of natural products contains complex bridged/polycyclic scaffolds with interesting biological profiles. They are thus attractive synthetic targets. Starting from 1963, twenty-eight natural products having the pseudoindoxyl scaffold have been isolated, among which the synthesis of 13 natural products has been accomplished. In this review, we highlight the completed as well as the formal total synthesis of the natural products with a spiro-pseudoindoxyl ring, with a focus on their development. The challenges and the future perspective based on the recent developments in the field will also be discussed. We strongly believe that this review will not only update but also attract the attention of researchers in dealing with the synthesis of pseudoindoxyl compounds.
Collapse
Affiliation(s)
- Pawan S Dhote
- Organic Chemistry Division, CSIR-National Chemical Laboratory Dr Homi Bhabha Road, Pune-411008, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Pitambar Patel
- CSIR-North East Institute of Science and Technology, Assam-785006, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Kumar Vanka
- Physical Chemistry Division, CSIR-National Chemical Laboratory Dr Homi Bhabha Road, Pune-411008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Chepuri V Ramana
- Organic Chemistry Division, CSIR-National Chemical Laboratory Dr Homi Bhabha Road, Pune-411008, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| |
Collapse
|
9
|
Cholewczynski AE, Williams PC, Pierce JG. Stereocontrolled Synthesis of (±)-Melokhanine E via an Intramolecular Formal [3 + 2] Cycloaddition. Org Lett 2020; 22:714-717. [PMID: 31908171 PMCID: PMC7662073 DOI: 10.1021/acs.orglett.9b04546] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A convergent sequence to access the indole alkaloid (±)-melokhanine E in 12-steps (8-step longest linear sequence) and an 11% overall yield is reported. The approach utilizes two cyclopropane moieties as reactive precursors to a 1,3-dipole and imine species to enable stereoselective construction of the core scaffold through a formal [3 + 2] cycloaddition. The natural product was evaluated for its antimicrobial activity based on isolation reports; however, no activity was observed. The reported efforts serve as a synthetic platform to prepare an array of alkaloids bearing this core structural motif.
Collapse
Affiliation(s)
- Anna E Cholewczynski
- Department of Chemistry, College of Sciences , NC State University , Raleigh , North Carolina 27695 , United States
| | - Peyton C Williams
- Department of Chemistry, College of Sciences , NC State University , Raleigh , North Carolina 27695 , United States
| | - Joshua G Pierce
- Department of Chemistry, College of Sciences , NC State University , Raleigh , North Carolina 27695 , United States
| |
Collapse
|