Synthesis of novel heterocycles and macrocycles via Rh(II)-catalyzed decomposition of N-Sulfonyl-1,2,3-triazoles

Abstract

α-Imino carbenes generated from N-sulfonyl-1,2,3-triazoles undergo many original processes, from cyclopropanations to C-H insertion reactions, and subsequent transformations. The aim of this PhD was to develop new synthetic methodologies involving these reactive intermediates. For instance, the Rh(II)-catalyzed reaction of N-sulfonyl-1,2,3-triazoles with oxetanes was tested. Depending on reaction conditions or substrate selection, 2-imino tetrahydrofurans, 13-membered sulfonimidates or 15-membered aza-macrocycles are generated selectively via formal [1+4], [5+4+4] and [3+4+4+4] condensations of α-imino carbenes and oxetanes. Moreover, straightforward access to novel polycyclic indoline-benzodiazepines with exclusive diastereoselectivity (d.r. > 49:1) was achieved using Troger Bases as substrates. Treatment of other stable aminals (e.g. imidazolidines) with N-sulfonyl triazoles led to the direct formation of fused indoline-piperazines via subsequent ylide formation, [1,2]-Stevens and Friedel-Crafts reactions. Finally, reaction with oxazolidines under dirhodium catalysis led to 1,3,6- or 1,4,6- oxadiazocines in good yields. Regioselectivity was achieved by modifying the nature of the nitrogen substituents (with EDG or EWG).