Denitrogenative cleavage of benzotriazoles and benzotriazinones, and selective N-desulfonylation of benzotriazoles by aluminum halides. (3rd August 2022)

• Record Type: Journal Article
• Authors: Dong, Bingqian; Liu, Yunfeng; Yang, Pengtao; Sang, Dayong; Tian, Juan; Li, Li; Long, Sihui
• Is Part Of: Tetrahedron letters. Volume 103(2022)
• Publication Date: 2022-08-03
• Subjects: Aluminum triiodide -- Neighboring group participation -- Desulfonylation; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2022.153965
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: Benzotriazoles bearing a hydroxy or acyl group can be cleaved by AlI3 . 1-Sulfonylbenzotriazoles are chemoselectively desulfonylated by AlI3 . Cleavage of 3-alkylbenzotriazinones by AlI3 affords 2-iodobenzamides. Cleavage of 3-arylbenzotriazinones by AlI3 provides 1-phenanthridinones. AlCl3 reacts with 1-acetylbenzotriazole and benzotriazinones differently. Abstract: Regiospecific denitrogenative cleavage and chemoselective N -desulfonylation of benzotriazoles and benzotriazinones by aluminum halides are investigated. Products of these transformations are dependent on the N -substituents as well as the aluminum halides. For benzotriazoles bearing an N -hydroxy or acetyl substituent, denitrogenative cleavage occurs that affords 2′-iodoacetanilides as the products when carried out in the presence of AlI3 and acetic anhydride. Analogous cleavage of benzotriazinones by AlI3 furnishes 2-iodobenazmides or 1-phenanthridinones. In contrast, treatment of 1-acetylbenzotriazole and 1, 2, 3-benzotriazones with AlCl3 provided benzotriazole and quinazolinones, respectively. 1-Sulfonylbenzotriazoles, to the contrary, prefer to undergo N -desulfonylation. AlI3 is unreactive towards typical aromatic sulfonamides, making the deprotection of 1-sulfonylated benzotriazoles chemoselective.