We have developed a continuous flow C3‐formylation technique for indoles using hexamethylenetetramine (HMTA) and iodine. A mixed solvent system of DMF–H₂O (1:1, vol/vol) completely dissolves reagents and prevents clogging of microchannels during fluid flow. The continuous flow technique provides maximized mixing and excellent heat transfer efficiency. Thus, flow chemistry accelerates the rate of C3‐formylation of indoles in the absence of a strong acid, base, or metal catalyst. We show that high yields of C3‐formylated indoles (up to 83%) can be obtained at 150°C when the residence time is as low as 8 min.

中文翻译：

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连续流动中吲哚的C3甲酰化

我们已经开发了使用六亚甲基四胺（HMTA）和碘的吲哚连续流动C3甲酰化技术。DMF–H ₂ O（1：1，体积/体积）的混合溶剂系统可以完全溶解试剂，并防止流体流动过程中微通道的堵塞。连续流技术可提供最大程度的混合，并具有出色的传热效率。因此，在没有强酸，强碱或金属催化剂的情况下，流化学可加快吲哚的C3甲酰化速率。我们显示，当停留时间低至8分钟时，可以在150°C下获得高产率的C3甲酰化吲哚（高达83％）。