Continuous‐Flow Amide and Ester Reductions Using Neat Borane Dimethylsulfide Complex
作者:Sándor B. Ötvös、C. Oliver Kappe
DOI:10.1002/cssc.201903459
日期:2020.4.7
importance in synthetic chemistry, and there are numerous protocols for executing these transformations employing traditional batch conditions. Notably, strategies based on flow chemistry, especially for amide reductions, are much less explored. Herein, a simple process was developed in which neat borane dimethylsulfide complex (BH3 ⋅DMS) was used to reduce various esters and amides under continuous-flow conditions
酰胺和酯的还原在合成化学中至关重要,有许多使用传统间歇条件进行这些转化的方案。值得注意的是,很少研究基于流动化学的策略,尤其是酰胺还原的策略。本文中,开发了一种简单的方法,其中使用纯硼烷二甲基硫醚络合物(BH3·DMS)在连续流动条件下还原各种酯和酰胺。利用可商购的硼烷试剂的无溶剂性质,实现了高底物浓度,从而实现了出色的生产率和E因子的显着降低。另外,在精心优化的短停留时间的情况下,以高选择性和高收率获得了相应的醇和胺。药物相关产品的多克级合成进一步证实了廉价且易于实施的流程协议的合成效用。由于其有益的特征,包括低的溶剂和还原剂消耗,高的选择性,简单性和固有的可扩展性,与使用金属氢化物作为还原剂的大多数典型的批量还原相比,本发明的方法对环境的关注较少。