1
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Paul B, Kundu S. The use of methanol as a C1 building block. Nat Protoc 2024; 19:2358-2385. [PMID: 38664579 DOI: 10.1038/s41596-024-00978-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 02/02/2024] [Indexed: 08/09/2024]
Abstract
Methanol is a key building block in the chemical industry. In recent years, it has been used as a C1 source in various organic transformations in the presence of a transition-metal catalyst. This protocol describes the ruthenium- and cobalt-catalyzed utilization of methanol in different types of methylation reactions and heterocycle synthesis. Initially, we describe the synthesis of tridentate ligands (L1-L3) and their corresponding Ru(II) complexes (Ru-1, -2 and -3) and then detail how to apply these Ru(II) complexes and Co/PP3 (PP3 = P(CH2CH2PPh2)3) in various methanol dehydrogenative coupling reactions. We discuss six types of transformations by using methanol or a methanol/water mixture. The experimental setup for all the catalytic reactions is similar and involves adding all the respective reagents and solvents to an argon-filled pressure tube, which is sealed (by screw cap) and refluxed at the indicated temperature before the desired products are isolated and characterized. The catalytic systems described in this protocol work well for both small-scale and preparative-scale synthesis of various N-methylated amines/amides, C-methylated products and quinazolinones. These catalytic reactions are greener and more sustainable than conventional synthesis methods, with only H2 and/or H2O as by-products, and we evaluate the 'green chemistry metrics' for a typical substrate. The total time required for the catalytic experiments described in this protocol is 16-28 h, and the operation time is 4 h. An average level of expertise in organic synthesis is required to carry out these protocols.
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Affiliation(s)
- Bhaskar Paul
- Department of Chemistry, University of Oxford, Oxford, UK.
- Department of Chemistry, Indian Institute of Technology, Kanpur, India.
| | - Sabuj Kundu
- Department of Chemistry, Indian Institute of Technology, Kanpur, India.
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2
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Templ J, Schnürch M. A Guide for Mono-Selective N-Methylation, N-Ethylation, and N-n-Propylation of Primary Amines, Amides, and Sulfonamides and Their Applicability in Late-Stage Modification. Chemistry 2024; 30:e202304205. [PMID: 38353032 DOI: 10.1002/chem.202304205] [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: 12/18/2023] [Indexed: 03/06/2024]
Abstract
This review provides a comprehensive overview of mono-alkylation methodologies targeting crucial nitrogen moieties - amines, amides, and sulfonamides - found in organic building blocks and pharmaceuticals. Emphasizing the intersection of chemical precision with drug discovery, the central challenge addressed is achieving one-pot mono-selective short-chain N-alkylations (methylations, ethylations, and n-propylations), preventing undesired overalkylation. Additionally, sustainable, safe, and benign alternatives to traditional alkylating agents, including alcohols, carbon dioxide, carboxylic acids, nitriles, alkyl phosphates, quaternary ammonium salts, and alkyl carbonates, are explored. This review, categorized by the nature of the alkylating agent, aids researchers in selecting suitable methods for mono-selective N-alkylation.
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Affiliation(s)
- Johanna Templ
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163, 1060, Vienna, Austria
| | - Michael Schnürch
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163, 1060, Vienna, Austria
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3
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Gautam N, Logdi R, P S, Roy A, Tiwari AK, Mandal SK. Bicyclic (alkyl)(amino)carbene (BICAAC) in a dual role: activation of primary amides and CO 2 towards catalytic N-methylation. Chem Sci 2023; 14:5079-5086. [PMID: 37206403 PMCID: PMC10189868 DOI: 10.1039/d3sc01216f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 04/19/2023] [Indexed: 05/21/2023] Open
Abstract
Herein, we report the first catalytic methylation of primary amides using CO2 as a C1 source. A bicyclic (alkyl)(amino)carbene (BICAAC) exhibits dual role by activating both primary amide and CO2 to carry out this catalytic transformation which enables the formation of a new C-N bond in the presence of pinacolborane. This protocol was applicable to a wide range of substrate scopes, including aromatic, heteroaromatic, and aliphatic amides. We successfully used this procedure in the diversification of drug and bioactive molecules. Moreover, this method was explored for isotope labelling using 13CO2 for a few biologically important molecules. A detailed study of the mechanism was carried out with the help of spectroscopic studies and DFT calculations.
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Affiliation(s)
- Nimisha Gautam
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur Campus Nadia 741246 West Bengal India
| | - Ratan Logdi
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur Campus Nadia 741246 West Bengal India
| | - Sreejyothi P
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur Campus Nadia 741246 West Bengal India
| | - Antara Roy
- Department of Chemistry, Indian Institute of Technology Kharagpur Kharagpur 721302 West Bengal India
| | - Ashwani K Tiwari
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur Campus Nadia 741246 West Bengal India
| | - Swadhin K Mandal
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur Campus Nadia 741246 West Bengal India
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4
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Recent advances in the catalytic N-methylation and N-trideuteromethylation reactions using methanol and deuterated methanol. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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5
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Sheetal, Mehara P, Das P. Methanol as a greener C1 synthon under non-noble transition metal-catalyzed conditions. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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6
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Templ J, Gjata E, Getzner F, Schnürch M. Monoselective N-Methylation of Amides, Indoles, and Related Structures Using Quaternary Ammonium Salts as Solid Methylating Agents. Org Lett 2022; 24:7315-7319. [PMID: 36190781 PMCID: PMC9578047 DOI: 10.1021/acs.orglett.2c02766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
We herein report the use of phenyl trimethylammonium
iodide (PhMe3NI) as a safe, nontoxic, and easy-to-handle
reagent for an
absolutely monoselective N-methylation of amides and related compounds
as well as for the N-methylation of indoles. In addition, we expanded
the method to N-ethylation using PhEt3NI. The ease of operational
setup, high yields of ≤99%, high functional group tolerance,
and especially the excellent monoselectivity for amides make this
method attractive for late-stage methylation of bioactive compounds.
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Affiliation(s)
- Johanna Templ
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163, 1060 Wien, Austria
| | - Edma Gjata
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163, 1060 Wien, Austria
| | - Filippa Getzner
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163, 1060 Wien, Austria
| | - Michael Schnürch
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163, 1060 Wien, Austria
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7
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Guo W, Liu Z, Wu F, Luo Y, Yao Z. [NN]‐Chelate nickel complexes with Schiff base ligands: Synthesis, structure and catalytic activity in green amidation reaction. Appl Organomet Chem 2022. [DOI: 10.1002/aoc.6808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Wen Guo
- School of Chemical and Environmental Engineering Shanghai Institute of Technology Shanghai China
| | - Zhen‐Jiang Liu
- School of Chemical and Environmental Engineering Shanghai Institute of Technology Shanghai China
| | - Fanhong Wu
- School of Chemical and Environmental Engineering Shanghai Institute of Technology Shanghai China
| | - Yu‐Zhou Luo
- Business School Guilin University of Technology Guilin China
| | - Zi‐Jian Yao
- School of Chemical and Environmental Engineering Shanghai Institute of Technology Shanghai China
- Key Lab of Synthetic Chemistry of Natural Substances Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences Shanghai China
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8
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Tandem silylation—desilylation reaction in the synthesis of N-methyl carboxamides. Russ Chem Bull 2022. [DOI: 10.1007/s11172-022-3473-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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9
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SINGH JITENDER, Sharma A. Green and Sustainable Visible Light-Mediated Formation of Amide Bonds: An Emerging Niche in Organic Chemistry. NEW J CHEM 2022. [DOI: 10.1039/d2nj02406c] [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
Amide bond is one of the most fascinating functional groups in nature due to its stability, conformational diversity, high bond polarity, and abundance in numerous natural products and drug candidates,...
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Ganguli K, Belkova N, Kundu S. Cyclometalated (NNC)Ru(II) complex catalyzed β-methylation of alcohols using methanol. Dalton Trans 2022; 51:4354-4365. [DOI: 10.1039/d1dt03967a] [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
Indolyl fragment containing phenanthroline based new ligands and their corresponding Ru(II) complexes were synthesized and fully characterized by various spectroscopic techniques. Catalytic activity of these newly synthesized cyclometalated (NNC)Ru(II) complexes...
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11
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Yingxian L, Wei C, Linchun Z, Ji-Quan Z, Yonglong Z, Chun L, Bing G, Lei T, Yuan-Yong Y. Catalytic N-methyl amidation of carboxylic acids under cooperative conditions. RSC Adv 2022; 12:20550-20554. [PMID: 35919177 PMCID: PMC9284536 DOI: 10.1039/d2ra03255d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/09/2022] [Indexed: 11/21/2022] Open
Abstract
The generation of N-methyl amides using simple acids with high atom economy is rare owning to the volatile nature of methyl amine. Herein, an atom economic protocol was disclosed to prepare this valuable motif under DABCO/Fe3O4 cooperative catalysis.
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Affiliation(s)
- Li Yingxian
- State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, 550014 Guiyang, P. R. China
| | - Chen Wei
- State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, 550014 Guiyang, P. R. China
| | - Zhao Linchun
- State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, 550014 Guiyang, P. R. China
| | - Zhang Ji-Quan
- State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, 550014 Guiyang, P. R. China
| | - Zhao Yonglong
- State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, 550014 Guiyang, P. R. China
| | - Li Chun
- State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, 550014 Guiyang, P. R. China
| | - Guo Bing
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, 550004 Guiyang, P. R. China
| | - Tang Lei
- State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, 550014 Guiyang, P. R. China
| | - Yang Yuan-Yong
- State Key Laboratory of Functions and Applications of Medicinal Plants, School of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, 550014 Guiyang, P. R. China
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12
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Paul B, Maji M, Panja D, Kundu S. Cobalt Catalyzed N‐Methylation of Amides using Methanol. ASIAN J ORG CHEM 2021. [DOI: 10.1002/ajoc.202100678] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Bhaskar Paul
- Department of Chemistry Indian Institute of Technology Kanpur Kanpur 208016 Uttar Pradesh (U.P. India
- Department of Chemistry University of California at Riverside Riverside California 92521 United States
| | - Milan Maji
- Department of Chemistry Indian Institute of Technology Kanpur Kanpur 208016 Uttar Pradesh (U.P. India
| | - Dibyajyoti Panja
- Department of Chemistry Indian Institute of Technology Kanpur Kanpur 208016 Uttar Pradesh (U.P. India
| | - Sabuj Kundu
- Department of Chemistry Indian Institute of Technology Kanpur Kanpur 208016 Uttar Pradesh (U.P. India
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13
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Kabadwal LM, Bera S, Banerjee D. Recent advances in sustainable organic transformations using methanol: expanding the scope of hydrogen-borrowing catalysis. Org Chem Front 2021. [DOI: 10.1039/d1qo01412a] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Recent progress relating to sustainable approaches using methanol as a C1-alkylating agent for C–Me and N–Me bond formation is discussed.
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Affiliation(s)
- Lalit Mohan Kabadwal
- Department of Chemistry, Laboratory of Catalysis and Organic Synthesis, Indian Institute of Technology Roorkee, Roorkee-247667, Uttarakhand, India
| | - Sourajit Bera
- Department of Chemistry, Laboratory of Catalysis and Organic Synthesis, Indian Institute of Technology Roorkee, Roorkee-247667, Uttarakhand, India
| | - Debasis Banerjee
- Department of Chemistry, Laboratory of Catalysis and Organic Synthesis, Indian Institute of Technology Roorkee, Roorkee-247667, Uttarakhand, India
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14
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Jin S, Yao H, Lin S, You X, Yang Y, Yan Z. Peroxide-mediated site-specific C–H methylation of imidazo[1,2-a]pyridines and quinoxalin-2(1H)-ones under metal-free conditions. Org Biomol Chem 2020; 18:205-210. [DOI: 10.1039/c9ob02328c] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
An effective approach to realize the direct methylation of imidazo[1,2-a]pyridines and quinoxalin-2(1H)-ones with peroxides under metal-free conditions is described.
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Affiliation(s)
- Shengzhou Jin
- Department of Chemistry
- Nanchang University
- Nanchang
- P. R. China
| | - Hua Yao
- Department of Chemistry
- Nanchang University
- Nanchang
- P. R. China
| | - Sen Lin
- Department of Chemistry
- Nanchang University
- Nanchang
- P. R. China
| | - Xiaoqing You
- Department of Chemistry
- Nanchang University
- Nanchang
- P. R. China
| | - Yao Yang
- Department of Chemistry
- Nanchang University
- Nanchang
- P. R. China
| | - Zhaohua Yan
- Department of Chemistry
- Nanchang University
- Nanchang
- P. R. China
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15
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Paul B, Maji M, Panja D, Kundu S. Tandem Transformation of Aldoximes to N‐Methylated Amides Using Methanol. Adv Synth Catal 2019. [DOI: 10.1002/adsc.201900962] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Bhaskar Paul
- Department of ChemistryIndian Institute of Technology Kanpur Kanpur, Uttar Pradesh India
| | - Milan Maji
- Department of ChemistryIndian Institute of Technology Kanpur Kanpur, Uttar Pradesh India
| | - Dibyajyoti Panja
- Department of ChemistryIndian Institute of Technology Kanpur Kanpur, Uttar Pradesh India
| | - Sabuj Kundu
- Department of ChemistryIndian Institute of Technology Kanpur Kanpur, Uttar Pradesh India
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