Bifunctional-thiourea-catalyzed diastereo- and enantioselective aza-Henry reaction
Bifunctional-thiourea-catalyzed diastereo- and enantioselective aza-Henry reaction
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DOI：
10.1002/chem.200500735
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发表时间：
2006-01-01
影响因子：
4.3
通讯作者：
Takemoto, Y
中科院分区：
文献类型：
--
作者：
Xu, XN;Furukawa, T;Takemoto, Y
双功能硫脲 la 催化硝基烷烃与 N-Boc-亚胺的氮杂-Henr 反应，生成具有良好至高非对映选择性和对映选择性的顺式-β-硝基胺。除催化剂外，该反应不需要额外的试剂，例如路易斯酸或路易斯碱。亚胺的N-保护基团对产物的手性具有决定性作用，即N-Bocimines的反应产生R加合物作为主要产物，而N-膦酰亚胺的相同反应提供相应的S加合物。带有芳基、醇、醚和酯基团的各种类型的硝基烷烃可用作亲核试剂，以良好的产率和高对映体过量提供各种有用的手性结构单元。通过转化为手性哌啶衍生物（例如 CP-99,994），证明了加成产物的合成多功能性。
Bifunctional thiourea la catalyzes aza-Henr reaction of nitroal-kanes with N-Boc-imines to give syn-beta-nitroamines with good to high diastereo- and enantioselectivity. Apart from the catalyst, the reaction requires no additional reagents such as a Lewis acid or a Lewis base. The N-protecting groups of the imines have a determining effect on the chirality of the products, that is, the reaction of N-Bocimines gives R adducts as major products, whereas the same reaction of N-phosphonoylimines furnishes the corresponding S adducts. Various types of nitroalkanes bearing aryl, alcohol, ether, and ester groups can be used as nucleophiles, providing access to a wide range of useful chiral building blocks in good yield and high enantiomeric excess. Synthetic versatility of the addition products is demonstrated by the transformation to chiral piperidine derivatives such as CP-99,994.