College of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610041, P. R. China.
Chem Commun (Camb). 2020 Feb 25;56(16):2499-2502. doi: 10.1039/c9cc09637j.
Hydroxyl alkylation of indoles by Friedel-Crafts reaction with a carbonyl compound is a useful strategy. However, the reaction was restricted to ketones due to the easy formation of a bisindole byproduct. Therefore, hydroxyl alkylation of an aldehyde with indole is confronted with great challenges. Here, we report an efficient strategy for asymmetric hydroxyl alkylation of 2-substituted indoles with aldehydes under 0.1 mol% chiral phosphoric acid. A series of α-hydroxyl ketones were obtained in high yields (up to 99%) and good enantioselectivities (up to 97%).
吲哚与羰基化合物的傅-克烷基化反应是一种有用的策略。然而，由于双吲哚副产物的容易形成，该反应仅限于酮。因此，醛与吲哚的羟烷基化反应面临巨大的挑战。在这里，我们报道了一种在 0.1 摩尔%手性磷酸存在下高效合成 2-取代吲哚与醛的不对称羟烷基化反应的策略。一系列的α-羟基酮以高产率（高达 99%）和良好的对映选择性（高达 97%）得到。
