Solid Superbase‐Catalyzed Stereoselective 1,4‐Addition Reactions of Simple Amides in Batch and Continuous‐Flow Systems
作者:Parijat Borah、Yasuhiro Yamashita、Shū Kobayashi
DOI:10.1002/adsc.201900364
日期:2019.8.21
The utilization of a catalytic solid superbase in fine synthesis is challenging. Here, we employed K/γ‐Al2O3 catalytically as a highly efficient solid superbase to perform direct 1,4‐addition reactions of simple amides with α,β‐unsaturated carbonyls. The desired 1,5‐dicarbonyl compounds were obtained in high yields with excellent anti‐diastereoselectivities. K/γ‐Al2O3 showed a Hammett basicity of 37>H_≥35
在精细合成中使用催化固体超强碱具有挑战性。在这里,我们采用的K /γ-Al系2 ö 3催化作为高效固体超强以执行与α,β不饱和羰基化合物的简单酰胺的直接1,4-加成反应。以高收率和优异的获得所期望的1,5-二羰基化合物反-diastereoselectivities。K /γ-Al系2 ö 3显示出37的哈米特碱度> ħ _≥35。使用TGA-DTA对固体基质进行了表征27使用Al固态NMR光谱和XPS来确定超碱性的起源。通过使用新型固体超碱催化的1,4加成方法论证了1,5-二羰基化合物的连续流动合成。我们还发现K /γ-Al的电位2 Ó 3在不对称1,4-加成反应。