Bifunctional amino thiourea-catalyzed asymmetric additions of several nucleophiles into electron-deficient unsaturated compounds such as nitroolefins, ?,?-unsaturated imides, imines, and azodicarboxylates are described. We discovered that bifunctional thioureas bearing a
tertiary amino group significantly accelerated several nucleophilic addition reactions of active methylene compounds to electron-deficient double bonds. In these reactions, a strong hydrogen-bonding ability of the thiourea moiety as well as an appropriate Brønsted basicity of the tertiary
amine is crucial for high enantioselectivity. This dual activation of both nucleophiles and electrophiles by the bifunctional thiourea expanded the applicability of the thiourea-catalyzed enantioselective reaction. In addition, these organocatalyzed asymmetric reactions were successfully applied
to the concise asymmetric synthesis of natural products and medicinal candidates such as epibatidine, baclofen, and CP-99,994.
双功能氨基硫脲催化的不对称加成反应将几种亲核试剂加入到电子不足的不饱和化合物中,如硝基烯烃、α,β-不饱和亚酰胺、亚胺和叠氮二羧酸酯。我们发现,含有三级胺基的双功能硫脲显著加速了活性亚甲基化合物与电子不足双键的几种亲核加成反应。在这些反应中,硫脲基团的强氢键能力以及三级胺的适当Brønsted碱性对高对映选择性至关重要。双功能硫脲对亲核试剂和电子亲电试剂的双重活化扩展了硫脲催化的不对称反应的适用范围。此外,这些有机催化的不对称反应成功应用于天然产物和药用候选化合物的简洁不对称合成,如蛙毒碱、氯硝西泮和CP-99,994。