A hydroxyalkylation of N-heteroaromatics with aldehydes was achieved using a binary hybrid catalyst system comprising an acridinium photoredox catalyst and a thiophosphoric acid organocatalyst. The reaction proceeded through the following sequence: 1) photoredox-catalyzed single-electron oxidation of a thiophosphoric acid catalyst to generate a thiyl radical, 2) cleavage of the formyl C‒H bond of the aldehyde substrates by a thiyl radical acting as a hydrogen atom transfer catalyst to generate acyl radicals, 3) Minisci-type addition of the resulting acyl radicals to N-heteroaromatics, and 4) a spin-center shift, photoredox-catalyzed single-electron reduction, and protonation to produce secondary alcohol products. This metal-free hybrid catalysis proceeded under mild conditions for a wide range of substrates, including isoquinolines, quinolines, and pyridines as N-heteroaromatics, as well as both aromatic and aliphatic aldehydes, and tolerated various functional groups. The reaction was applicable to late-stage derivatization of drugs and their leads.

中文翻译：

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N-杂芳烃与醛的光催化氧化还原中性羟烷基化

使用包含吖啶鎓光氧化还原催化剂和硫代磷酸有机催化剂的二元混合催化剂体系实现了N-杂芳族化合物与醛的羟烷基化。反应按照以下顺序进行：1）硫代磷酸催化剂的光氧化还原催化单电子氧化生成硫自由基，2）硫自由基作为氢裂解醛底物的甲酰基C-H键原子转移催化剂产生酰基自由基，3)将所得酰基自由基与N-杂芳族化合物进行Minisci型加成，以及4)自旋中心转移、光氧化还原催化的单电子还原和质子化以产生仲醇产物。这种无金属杂化催化在温和的条件下进行，适用于多种底物，包括异喹啉、喹啉和吡啶作为 N-杂芳族化合物，以及芳香族和脂肪族醛，并耐受各种官能团。该反应适用于药物及其先导化合物的后期衍生化。