Electro-oxidative Methylation of 2-Isocyanobiaryls Using N,N-dimethylformamide (DMF) as Carbon Source: Synthesis of 6-Methylphenanthridines

Kannika La-Ongthong; Teera Chantarojsiri; Darunee Soorukram; Pawaret Leowanawat; Vichai Reutrakul; Chutima Kuhakarn

doi:10.1002/asia.202400176

Electro-oxidative Methylation of 2-Isocyanobiaryls Using N,N-dimethylformamide (DMF) as Carbon Source: Synthesis of 6-Methylphenanthridines

Chem Asian J. 2024 May 2;19(9):e202400176. doi: 10.1002/asia.202400176. Epub 2024 Apr 10.

Authors

Kannika La-Ongthong^{1

2}, Teera Chantarojsiri^{1

2}, Darunee Soorukram^{1

2}, Pawaret Leowanawat^{1

2}, Vichai Reutrakul^{1

2}, Chutima Kuhakarn^{1

2}

Affiliations

¹ Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand.
² Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok, 10400, Thailand.

PMID: 38489229
DOI: 10.1002/asia.202400176

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.

Keywords: 2-Isocyanobiaryls; 6-Methylphenanthridines; Electrochemical; Methylation; N,N-Dimethylformamide.

Abstract

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