Transition Metal-Catalyzed Asymmetric Synthesis Based on Allene and Cyclopropane Chemistry

我们已经开发了新的不对称合成方法与过渡金属催化剂利用烯和环丙烷的功能。不饱和化合物，如二烯和炔，在金属催化剂的作用下容易形成新的碳-碳键，形成碳环或杂环。在这类体系中引入烯和环丙烷的功能，为复杂有机分子的精细化提供了化学特性方面的研究方向。我们最近在金属催化剂上对烯和环丙烷的不对称反应的研究结果如下：1。用手性膦配体，钯催化烯与碘苯和亲核试剂的反应提供了α， β功能化化合物的高对映选择性。钯催化含碘苯基的烯烯与亲核试剂的反应，更多的亲核试剂通过分子内碳置换和分子内亲核取代直接提供三环化合物。含碘苯基的烯烯与亲核试剂在手性膦配体存在下进行钯催化反应，得到具有高对映选择性的光学活性三环化合物。利用氨基组分作为亲核试剂，实现了环吲哚化合物的不对称合成，具有较高的对映效率。钛催化的烯-烯体系反应可产生分子内环加成产物、[2+2]环加成产物和烯反应产物。将反应应用于手性烯系，得到了反应的立体特异性。钯催化环丙烯-甲基环丙烷体系的反应钯催化环丙烯-甲基环丙烷体系与亲电烯烃的反应提供了高产的[3+2]环加成反应产物。这一结果表明钯催化反应生成的1,3 -亲极试剂具有较高的活性。少

We have developed novel asymmetric synthetic methodologies with transition metal catalysts using allene and cyclopropane functionalities. Unsaturated compounds such as dienes and enynes are activated with metal catalysts to form new carbon-carbon bonds easily, providing carbocycles or heterocycles. Introduction of allene and cyclopropane functions in such systems provides much interest for us in term of their chemical characteristics for elaboration of complex organic molecules. Our recent results of the asymmetric reactions of allenes and cyclopropanes using metal catalysts are as follows.1. Asymmetric synthesis by asymmetric carbopalladation of allenes The palladium-catalyzed reaction of allenes with iodobenzene and nucleophiles using chiral phosphine ligands provided high enantioselectivity of α, β -functionalized compounds.2. Palladium-catalyzed reactions of allenes bearing iodophenyl groups with nucleophiles The palladium-catalyzed reactions of allenes bearing iodophenyl groups wi … More th nucleophiles provided directly tricyclic compounds by intramolecular carbopalladation followed by intramolecular nucleophilic substitution.3. Asymmetric synthesis of heterocycles by palladium-catalyzed reactions of allenes The palladium-catalyzed reactions of allenes bearing iodophenyl groups with nucleophiles were carried out in the presence of chiral phosphine ligands to give optically active tricyclic compounds with high enantioselectivity. On the use of amino components as nucleophiles, asymmetric synthesis of cyclic indole compounds was achieved with high enantioefficiency.4. Intramolecular metal-catalyzed reactions of allene-ene compounds Titanium-catalyzed reactions of allene-ene systems provided intramolecular cycloaddition products, [2+2] cycloaddition and ene reaction products. The stereospecificity of the reactions was obtained by appling the reactions to chiral allene systems.5. Palladium-catalyzed reactions of cyclopropylidenemethylcyclopropane systemsThe palladium-catalyzed reactions of cyclopropylidenemethylcyclopropane systems with electrophilic olefin provided [3+2] cycloaddition reaction products in high yields. This result indicates the existence of rather reactive 1, 3-dipolarophiles generated by the palladium-catalyzed reactions. Less