Preparation of N-(2-alkoxyvinyl)sulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines

• Published in: Journal of visualized experiments no. 131
• Main Authors: Bennett, John M, Shapiro, Jonathan D, Choinski, Krystina N, Mei, Yingbin, Aulita, Sky M, Dominguez, Giovanny M, Majireck, Max M
• Format: Journal Article
• Language: English
• Published: United States MyJove Corporation 03-01-2018
• Subjects: Benzofurans - chemical synthesis; Benzofurans - chemistry; Catalysis; Chemistry; Phenethylamines - chemical synthesis; Phenethylamines - chemistry; Sulfonamides - chemical synthesis; Sulfonamides - chemistry; Triazoles - chemistry
• ISSN: 1940-087X; 1940-087X
• DOI: 10.3791/56848

Decomposition of N-tosyl-1,2,3-triazoles with rhodium(II) acetate dimer in the presence of alcohols forms synthetically versatile N-(2-alkoxyvinyl)sulfonamides, which react under a variety of conditions to afford useful N- and O-containing compounds. Acid-catalyzed addition of alcohols or thiols to N-(2-alkoxyvinyl)sulfonamide-containing phthalans provides access to ketals and thioketals, respectively. Selective reduction of the vinyl group in N-(2-alkoxyvinyl)sulfonamide-containing phthalans via hydrogenation yields the corresponding phthalan in good yield, whereas reduction with sodium bis(2-methoxyethoxy)aluminumhydride generates a ring-opened phenethylamine analogue. Because the N-(2-alkoxyvinyl)sulfonamide functional group is synthetically versatile, but often hydrolytically unstable, this protocol emphasizes key techniques in preparing, handling, and reacting these pivotal substrates in several useful transformations.