Mechanochemical Synthesis of 1,2,6-Thiadiazine 1-Oxides from Sulfonimidamides and the Fluorescence Properties of the Products

Abstract

A solvent-free mechanochemical synthesis for 1,2,6thiadiazine 1-oxides starting from NH-sulfonimidamides and propargyl ketones has been developed. Lewis acids affect these one-pot aza-Michael-addition/cyclization/dehydration reaction sequences. The photophysical properties of the resulting heterocyclic sulfonimidamide derivatives were characterized.

1,2‐Benzothiazine Derivatives from Sulfonimidamides by Metal‐Catalyzed Annulation Reactions in Solution and under Solvent‐Free Mechanochemical Conditions

“…Methanol could only be substituted by ethanol, which gave 6 aa in 44% yield. As these results in solution were not satisfactory, we wondered if the reaction could also be performed under mechanochemical solvent‐free conditions [13,14] . Hence, all components required for the catalysis were mixed in a ball mill reactor for 6 h at 25 Hz, and starting from sulfonimidamide 1 a and α ‐sulfonyloxyketone 3 a as substrates, 6 aa was obtained in 22% yield (Table 1, entry 11).…”

Mechanochemical Synthesis of Organic Dyes and Fluorophores

“…AND FLUOROPHORES Bolm and co-workers prepared a series of 1,2,6-thiadiazole-1oxides ( 24) by aza-Michael addition followed by cyclocondensation reactions. 35 The cyclization of various sulfonimidamides (22) and propargyl ketones (23) in the presence of LaCl 3 (10 mol %) as the catalyst and Cs 2 CO 3 as the base was carried out in a mixer mill (MM400) at 25 Hz for 1 h to afford 24 in moderate to high yields (Scheme 6). Neutral alumina was used as the milling matrix for an otherwise sticky reaction mixture to significantly improve the yields.…”

Synthesis of Sulfonyl, Sulfonimidoyl, and Sulfoxyl Fluorides under Solvent-Free Mechanochemical Conditions in a Mixer Mill by Imidazole-to-Fluorine Exchange

“…Recently, we reported several studies in which sustainable mechanochemical methodologies in sulfur chemistry were applied. These studies have enabled us to synthesize a wide range of sulfur-containing compounds from a very different perspective. − …”