Curtius-type rearrangement of a sulphonyl azide

Abstract

Six products have been identified from the thermolysis of mesitylene-2-sulphonyl azide in dodecane : two are derived from a Curtius-type rearrangement of the corresponding sulphonyl nitrene.

Photochemistry of Matrix Isolated (Trifluoromethyl)sulfonyl Azide, CF3SO2N3

“…The present matrix isolation study on CF 3 SO 2 N 3 will contribute to the understanding of the fundamental chemistry of sulfonyl azides and helps to understand their complicated photochemistry in solution, which for a long time have impaired the broader application of sulfonyl azides as the nitrene precursor. − The distinct photodecomposition and thermal decomposition of the sulfonyl azides CF 3 SO 2 N 3 and FSO 2 N 3 , and the surprisingly different reactivity of the corresponding sulfonylnitrenes certainly demand further systematic theoretical studies.…”

“…Sulfonyl azides, RSO 2 N 3 , are important reagents in synthetic chemistry. − Similar to the reactions of related carbonyl azides, , both photodecomposition and thermal decomposition reactions of sulfonyl azides have been extensively studied in solution. The intervention of sulfonylnitrenes, RSO 2 N, were chemically inferred from secondary decomposition products. − A number of triplet sulfonylnitrenes have already been experimentally detected among the photolysis products of the corresponding azides by electron paramagnetic resonance (EPR) spectroscopy at low temperatures. − These early studies strongly suggested that sulfonylnitrenes adopt triplet ground states, and no straightforward evidence for a Curtius-type rearrangement was obtained.…”

Elusive Fluoro Sulfinyl Nitrite, FS(O)NO, Produced by Photolysis of Matrix‐isolated FS(O)2N

“…Provided that this photo‐rearrangement can be transferred to the analogous sulfonyl nitrenes, R S(O) 2 N, it would give access to sulfinyl nitrites, R S(O)NO. However, although the chemistry of sulfonyl nitrenes has been known for nearly a half century,15–19 spectroscopic studies on these intermediates are very limited. Low‐temperature EPR studies have established their triplet ground state nature,20,21 and a transient UV absorption band at 325 nm was attributed to 4‐methylbenzenesulfonyl nitrene in cyclohexane at 77 K 20.…”

“…Low‐temperature EPR studies have established their triplet ground state nature,20,21 and a transient UV absorption band at 325 nm was attributed to 4‐methylbenzenesulfonyl nitrene in cyclohexane at 77 K 20. It was claimed, that the Curtius rearrangement of sulfonyl nitrenes, R S(O) 2 N, yield unstable N‐sulfonyl imides, R N=SO 2 [Equation (3)] 15,19…”

Gas phase thermolysis of sulfonyl azides

“…With 2-methylbenzenesulfonyl azide (4), the intramolecular insertion product, benzylsultam (5), was obtained in 21% yield from gas phase thermolysis in the absence of benzene and in 13% yield with benzene present. This result is readily explained in terms of a sulfonylnitrene intermediate which inserts into the adjacent methyl group.…”