A photoinduced reaction of potassium alkyltrifluoroborates, sulfur dioxide, and alkynyl bromides under visible light irradiation at room temperature is developed, giving rise to alkylalkynyl sulfones in moderate to good yields. This transformation works well under photocatalysis with broad substrate scope by using sodium metabisulfite as the source of sulfur dioxide. Mechanistic studies show that the reaction is initiated by an alkyl radical generated in situ from potassium alkyltrifluoroborate in the presence of a photocatalyst. Then sulfonylation occurs through the insertion of sulfur dioxide to provide an alkylsulfonyl radical intermediate, which reacts with alkynyl bromide, leading to the corresponding alkylalkynyl sulfone.

中文翻译：

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通过烷基三氟硼酸钾，二氧化硫和炔基溴的反应光诱导合成烷基炔基砜

在室温下可见光照射下，烷基三氟硼酸钾，二氧化硫和炔基溴的光诱导反应得以发展，从而以中等至良好的产率产生了烷基炔基砜。通过使用偏亚硫酸氢钠作为二氧化硫的来源，这种转化在具有广泛底物范围的光催化下效果很好。机理研究表明，该反应是由在光催化剂存在下由烷基三氟硼酸钾原位生成的烷基引发的。然后通过插入二氧化硫进行磺酰化反应，以提供烷基磺酰基自由基中间体，该中间体与炔基溴化物反应，生成相应的烷基炔基砜。