Metal-free insertion of sulfur dioxide with aryl iodides and silyl enolates or allylic bromide under ultraviolet irradiation at room temperature is accomplished. This protocol provides a convenient route to sulfonated cyclic compounds under mild conditions. Not only N-(2-iodophenyl)-N-methylmethacrylamides but also 1-iodo-2-allenoxybenzene is workable. A plausible mechanism is proposed, which shows that during the reaction process, aryl radicals formed in situ from aryl iodides under ultraviolet irradiation undergo intramolecular 5-exo-cyclization, with subsequent sulfonylation via insertion of sulfur dioxide. The resulting sulfonyl radicals are further trapped by silyl enolates or allylic bromide giving rise to sulfonated cyclic compounds.

中文翻译：

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在紫外线照射下将二氧化硫与芳基碘化物无金属插入：直接接触磺化的环状化合物

在室温下紫外线照射下，实现了二氧化硫与芳基碘化物和甲硅烷基烯醇化物或烯丙基溴的无金属插入。该方案提供了在温和条件下制备磺化环状化合物的便捷途径。不仅N-（2-碘苯基）-N-甲基甲基丙烯酰胺而且1-碘-2-亚丙氧基苯也是可行的。一种可能的机理，提出了一种显示，在反应过程中，形成的芳基在原位在紫外线照射下从芳基碘经历分子内5-外型-cyclization，随后磺酰经由插入二氧化硫。所得的磺酰基自由基进一步被烯丙基甲硅烷基化物或烯丙基溴捕获，从而产生磺化的环状化合物。