Sugar-based primary amines have been employed as organocatalysts for the direct asymmetric Mannich reaction. By catalyst-screening experiments, we observed that catalysts bearing a hydroxy function at C-3 actively participated in the reaction, possibly through hydrogen bonding with the imine generated in situ, to provide β-amino carbonyl compounds with better diastereoselectivity and enantioselectivity. All the products were obtained in good to excellent enantiomeric excess.

中文翻译：

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d-氨基葡萄糖衍生的有机催化剂催化的直接不对称曼尼希反应

糖基伯胺已被用作直接不对称曼尼希反应的有机催化剂。通过催化剂筛选实验，我们观察到在 C-3 处带有羟基官能团的催化剂积极参与反应，可能是通过与原位生成的亚胺形成氢键，从而提供具有更好非对映选择性和对映选择性的 β-氨基羰基化合物。获得的所有产品都处于良好至极好的对映体过量。