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Holt E, Wang M, Harry SA, He C, Wang Y, Henriquez N, Xiang MR, Zhu A, Ghorbani F, Lectka T. An Electrochemical Approach to Directed Fluorination. J Org Chem 2023; 88:2557-2560. [PMID: 36702475 DOI: 10.1021/acs.joc.2c01886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Electrosynthesis has made a revival in the field of organic chemistry and, in particular, radical-mediated reactions. Herein, we report a simple directed, electrochemical C-H fluorination method. Employing a dabconium mediator, commercially available Selectfluor, and RVC electrodes, we provide a range of steroid-based substrates with competent regioselective directing groups, including enones, ketones, and hydroxy groups, as well as never reported before lactams, imides, lactones, and esters.
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Affiliation(s)
- Eric Holt
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Muyuan Wang
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Stefan Andrew Harry
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Chengkun He
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Yuang Wang
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Nicolas Henriquez
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Michael Richard Xiang
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Andrea Zhu
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Fereshte Ghorbani
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
| | - Thomas Lectka
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States
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Spino C, Aubert-Nicol S, Heinrich N, Lessard J. [Bis(trifluoroacetoxy)iodo]p-nitrobenzene and [Bis(trifluoroacetoxy)iodo]pentafluorobenzene as Lead Reagents for the Direct Ring Contraction of Lactams to Pyrrolidines. HETEROCYCLES 2019. [DOI: 10.3987/com-18-s(f)43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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4
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Pichette S, Winter DK, Lessard J, Spino C. Converting cycloalkanones into N-heterocycles: formal synthesis of (-)-gephyrotoxin 287C. J Org Chem 2013; 78:12532-44. [PMID: 24188015 DOI: 10.1021/jo402217e] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The photochemical rearrangement of N-activated lactams enables their ring contraction concomitant with the migration of a carbon onto a nitrogen atom. When coupled with the Beckmann rearrangement, this photochemical ring contraction converts cycloalkanones into N-heterocycles in a few steps and in a stereospecific manner. To showcase the method, we performed an efficient formal synthesis of (-)-gephyrotoxin 287C.
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Affiliation(s)
- Simon Pichette
- Département de Chimie, Université de Sherbrooke , Sherbrooke, Québec, Canada J1K 2R1
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5
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Pichette S, Aubert-Nicol S, Lessard J, Spino C. Photochemical and thermal ring-contraction of cyclic hydroxamic acid derivatives. J Org Chem 2012. [PMID: 23198744 DOI: 10.1021/jo3023507] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Cyclic hydroxamic acids can undergo a thermal ring contraction after an in situ triflation. High yields of ring-contraction products are obtained with DBU when the migrating carbon is a methylene, while best results are obtained with Et(3)N for the migration of quaternary carbons. In some cases, the regiochemical outcome of the reaction can be controlled by changing the base. This novel thermal rearrangement complements a similar but photochemical rearrangement of N-mesyloxylactams.
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Affiliation(s)
- Simon Pichette
- Département de Chimie, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1K 2R1
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6
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Pichette S, Aubert-Nicol S, Lessard J, Spino C. Regioselective Photochemical Rearrangement of N-Mesyloxylactams. European J Org Chem 2012. [DOI: 10.1002/ejoc.201101222] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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7
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Drouin A, Winter DK, Pichette S, Aubert-Nicol S, Lessard J, Spino C. Photochemical Rearrangement of N-Mesyloxylactams: Stereospecific Formation of N-Heterocycles. J Org Chem 2010; 76:164-9. [DOI: 10.1021/jo101805q] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alexandre Drouin
- Département de Chimie, Université de Sherbrooke, 2500 boul. Université, Sherbrooke, Québec, Canada, J1K 2R1
| | - Dana K. Winter
- Département de Chimie, Université de Sherbrooke, 2500 boul. Université, Sherbrooke, Québec, Canada, J1K 2R1
| | - Simon Pichette
- Département de Chimie, Université de Sherbrooke, 2500 boul. Université, Sherbrooke, Québec, Canada, J1K 2R1
| | - Samuel Aubert-Nicol
- Département de Chimie, Université de Sherbrooke, 2500 boul. Université, Sherbrooke, Québec, Canada, J1K 2R1
| | - Jean Lessard
- Département de Chimie, Université de Sherbrooke, 2500 boul. Université, Sherbrooke, Québec, Canada, J1K 2R1
| | - Claude Spino
- Département de Chimie, Université de Sherbrooke, 2500 boul. Université, Sherbrooke, Québec, Canada, J1K 2R1
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Winter DK, Drouin A, Lessard J, Spino C. Photochemical Rearrangement of N-Chlorolactams: A Route to N-Heterocycles through Concerted Ring Contraction. J Org Chem 2010; 75:2610-8. [DOI: 10.1021/jo100181h] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Dana K. Winter
- Département de Chimie, Université de Sherbrooke, 2500 Boul. Université, Sherbrooke, Québec, Canada J1K 2R1
| | - Alexandre Drouin
- Département de Chimie, Université de Sherbrooke, 2500 Boul. Université, Sherbrooke, Québec, Canada J1K 2R1
| | - Jean Lessard
- Département de Chimie, Université de Sherbrooke, 2500 Boul. Université, Sherbrooke, Québec, Canada J1K 2R1
| | - Claude Spino
- Département de Chimie, Université de Sherbrooke, 2500 Boul. Université, Sherbrooke, Québec, Canada J1K 2R1
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9
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Ibrahim-Ouali M, Rocheblave L. Recent advances in azasteroids chemistry. Steroids 2008; 73:375-407. [PMID: 18249432 DOI: 10.1016/j.steroids.2007.12.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Revised: 12/10/2007] [Accepted: 12/13/2007] [Indexed: 11/23/2022]
Abstract
Modified steroids have attracted a great deal of attention these last years. Their preparation is a stimulating challenge to the organic chemist, often demanding development of new and generally useful reactions. Moreover, the biological properties of modified steroids have proved to be of interest. The recent development in the partial and total syntheses of azasteroids is herein described.
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Affiliation(s)
- Malika Ibrahim-Ouali
- UMR 6180 CNRS and Universite d'Aix Marseille III: Chirotechnologies: catalyse et biocatalyse, Laboratoire de Synthese Organique associe au CNRS, Faculte des Sciences et Techniques de Saint Jerome, Marseille Cedex 20, France.
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Wang C, Wang S, Xu Y, Hu Y, Hu H. Preparation of (5 alpha,13 alpha)-D-azasteroids as key precursors of a new family of potential GABAA receptor modulators. Steroids 2003; 68:677-83. [PMID: 12957673 DOI: 10.1016/s0039-128x(03)00099-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Three groups of (5 alpha,13 alpha)-D-azasteroids, (5 alpha,13 alpha)-3-hydroxy-17a-aza-D-homoandrostans (12), (5 alpha,13 alpha)-3-hydroxy-17-aza-D-homoandrostans (15), and (5 alpha,13 alpha)-3-hydroxy-17-azaandrostans (17), were designed and synthesized as key precursors for the further preparation of a new family of potential GABAA receptor modulators from commercially available natural steroids (5 alpha)-3-hydroxyandrostane-17-ones (7).
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Affiliation(s)
- Cunde Wang
- Department of Chemistry, Nanjing University, Nanjing 210093, PR China
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