Visible-light-promoted photocatalyst-free alkylation and acylation of benzothiazoles

• Published in: Organic & biomolecular chemistry Vol. 19; no. 2; pp. 4487 - 4491
• Main Authors: Jiang, Pengxing, Liu, Li, Tan, Jiajing, Du, Hongguang
• Format: Journal Article
• Language: English
• Published: CAMBRIDGE Royal Soc Chemistry 26.05.2021; Royal Society of Chemistry
• Subjects: Acylation; Alkylation; Benzothiazole; Chemistry; Chemistry, Organic; Esters; Irradiation; Photocatalysts; Physical Sciences; Radiation; Science & Technology; Sodium persulfate; AZOLES; C-H ALKYLATION; CROSS-COUPLING REACTIONS; ELECTRON-TRANSFER; 2-ACYLBENZOTHIAZOLES; METAL; ALDEHYDES; ALPHA-KETO ACIDS; MINISCI ACYLATION; N-HETEROCYCLES
• ISSN: 1477-0520; 1477-0539
• DOI: 10.1039/d1ob00734c

Herein we report a protocol for the visible-light-mediated alkylation/acylation reaction of benzothiazoles. Alkyl/acyl substituted Hantzsch esters are easily prepared and rationally used as radical precursors. In the presence of BF 3 ·Et 2 O and Na 2 S 2 O 8 , various benzothiazole derivatives were readily obtained in good yields. Our user-friendly protocol can proceed by simple irradiation with blue LEDs ( λ = 465 nm) and without the assistance of external photocatalysts. The reaction is also characterized by mild conditions and scalability, thus offering an alternative and efficient tool for the synthesis of 2-functionalized benzothiazoles. A visible-light-mediated alkylation/acylation reaction of benzothiazoles was described using the BF 3 ·Et 2 O/Na 2 S 2 O 8 system.