1
|
La-Ongthong K, Chantarojsiri T, Soorukram D, Leowanawat P, Reutrakul V, Kuhakarn C. Electro-oxidative Methylation of 2-Isocyanobiaryls Using N,N-dimethylformamide (DMF) as Carbon Source: Synthesis of 6-Methylphenanthridines. Chem Asian J 2024; 19:e202400176. [PMID: 38489229 DOI: 10.1002/asia.202400176] [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: 02/19/2024] [Revised: 03/14/2024] [Accepted: 03/14/2024] [Indexed: 03/17/2024]
Abstract
A benign electrochemical method to access 6-methylphenanthridines from 2-isocyanobiaryls using N,N-dimethylformamide (DMF) as a methyl source is reported. The protocol operates at ambient temperature without the need for harmful methylating reagents. Mechanistic studies suggested that DMF delivered a methylene synthon, followed by reduction at the cathode and tautomerization. The method offers environmental benefits by avoiding metal-based reagents and harsh conditions.
Collapse
Affiliation(s)
- Kannika La-Ongthong
- Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand
- Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand
| | - Teera Chantarojsiri
- Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand
- Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand
| | - Darunee Soorukram
- Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand
- Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand
| | - Pawaret Leowanawat
- Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand
- Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand
| | - Vichai Reutrakul
- Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand
- Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand
| | - Chutima Kuhakarn
- Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand
- Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand
| |
Collapse
|
2
|
Deng H, Xiang L, Yuan Z, Lin B, He Y, Hou Q, Ruan Y, Zhang J. Facile access to S-methyl dithiocarbamates with sulfonium or sulfoxonium iodide as a methylation reagent. Org Biomol Chem 2023; 21:6474-6478. [PMID: 37523154 DOI: 10.1039/d3ob00932g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/01/2023]
Abstract
Efficient access to S-methyl dithiocarbamates was achieved with sulfonium or sulfoxonium iodide as a methylation reagent. This method is reliable for the synthesis of dithiocarbamates from primary or secondary amines, with sulfoxonium iodide demonstrating more robust methylation capability than sulfonium iodide. Moreover, it also enables facile access to S-trideuteromethyl dithiocarbamates via sulfoxonium metathesis between sulfoxonium iodide and DMSO-d6 with high yields.
Collapse
Affiliation(s)
- Huiying Deng
- Artemisinin Research Center and The First Affiliated Hospital, Guangzhou University of Chinese Medicine, 12 Jichang Road, Guangzhou 510405, China.
| | - Lingling Xiang
- Artemisinin Research Center and The First Affiliated Hospital, Guangzhou University of Chinese Medicine, 12 Jichang Road, Guangzhou 510405, China.
| | - Zhijun Yuan
- Artemisinin Research Center and The First Affiliated Hospital, Guangzhou University of Chinese Medicine, 12 Jichang Road, Guangzhou 510405, China.
| | - Bohong Lin
- Artemisinin Research Center and The First Affiliated Hospital, Guangzhou University of Chinese Medicine, 12 Jichang Road, Guangzhou 510405, China.
| | - Yiting He
- Artemisinin Research Center and The First Affiliated Hospital, Guangzhou University of Chinese Medicine, 12 Jichang Road, Guangzhou 510405, China.
| | - Qi Hou
- Artemisinin Research Center and The First Affiliated Hospital, Guangzhou University of Chinese Medicine, 12 Jichang Road, Guangzhou 510405, China.
| | - Yaoping Ruan
- Artemisinin Research Center and The First Affiliated Hospital, Guangzhou University of Chinese Medicine, 12 Jichang Road, Guangzhou 510405, China.
| | - Jing Zhang
- Artemisinin Research Center and The First Affiliated Hospital, Guangzhou University of Chinese Medicine, 12 Jichang Road, Guangzhou 510405, China.
| |
Collapse
|
3
|
Fakis M, Petropoulos V, Hrobárik P, Nociarová J, Osuský P, Maiuri M, Cerullo G. Exploring Solvent and Substituent Effects on the Excited State Dynamics and Symmetry Breaking of Quadrupolar Triarylamine End-Capped Benzothiazole Chromophores by Femtosecond Spectroscopy. J Phys Chem B 2022; 126:8532-8543. [PMID: 36256786 DOI: 10.1021/acs.jpcb.2c03103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We investigate herein the excited state dynamics and symmetry breaking processes in three benzothiazole-derived two-photon absorbing chromophores by femtosecond fluorescence and transient absorption (fs-TA) spectroscopies in solvents of various polarity. The chromophores feature a quasi-quadrupolar D-π-A-π-D architecture comprised of an electron-withdrawing benzothiazole core and lateral triphenylamine donors (Qbtz-H), while the acceptor strength of the central unit is enforced by attached cyano groups (Qbtz-CN) and the electron-donating strength of the arylamine moieties by introduction of peripheral methoxy groups (Qbtz'-CN). Steady state spectroscopy reveals positive solvatochromism, which is mostly pronounced for Qbtz'-CN. Femtosecond spectroscopy of Qbtz-H reveals the coexistence of the Franck-Condon (FC) state and states populated after symmetry breaking (SB) in low-polarity solvents such as toluene and tetrahydrofuran, while the SB state becomes favorable in polar acetonitrile. For the other two molecules possessing a stronger electron-accepting unit and thus more polar excited state, SB takes place even in low-polarity solvents, as shown by fs-TA spectroscopy. Global fitting of the fs-TA spectra together with investigation of the evolution associated spectra (EAS) reveals the existence of an initial FC state in Qbtz-H, in all studied solvents, which relaxes toward Intermediate Charge Transfer (I-CT) and SB states. On the other hand, for Qbtz-CN and Qbtz'-CN in more polar solvents, the FC state undergoes ultrafast relaxation toward symmetry-broken charge transfer (SB-CT) states which in turn show very fast recombination to the ground state. Our measurements confirm that the extent of symmetry breaking is larger for D-π-A-π-D systems with the stronger acceptor core and increases further by increasing electron-donating strength of triarylamine moieties, giving rise to symmetry breaking in these nonionic quadrupolar molecules with ethynylene (triple bond) π-spacers also in less polar solvents.
Collapse
Affiliation(s)
- Mihalis Fakis
- Department of Physics, University of Patras, PatrasGR-26500, Greece
| | - Vasilis Petropoulos
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133Milan, Italy
| | - Peter Hrobárik
- Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, SK-84215Bratislava, Slovakia
| | - Jela Nociarová
- Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, SK-84215Bratislava, Slovakia
| | - Patrik Osuský
- Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, SK-84215Bratislava, Slovakia
| | - Margherita Maiuri
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133Milan, Italy
| | - Giulio Cerullo
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133Milan, Italy
| |
Collapse
|