Hitce Julien, Retailleau Pascal, Baudoin Olivier
ICSN-CNRS, Gif-sur-Yvette, France.
Chemistry. 2007;13(3):792-9. doi: 10.1002/chem.200600811.
A novel catalytic system, based on a mixture of palladium acetate and tris(5-fluoro-2-methylphenyl)phosphane (F-TOTP), has been designed for the intramolecular C--H functionalization of alkane segments. Among other analogues of tris(2-methylphenyl)phosphane (P(o-tol)(3)), F-TOTP was shown to have the optimal metal-bonding properties for this reaction. This catalytic system operated under milder reaction conditions that allowed the regioselective production of various olefins adjacent to a quaternary benzylic carbon atom, as well as novel bi- and tricyclic molecules. A general mechanism was proposed, with the preferential formation of a six-membered palladium(II) palladacycle after oxidative addition and cyclopalladation. The regioselective C--H functionalization of alkyl groups into olefins was illustrated in the synthesis of the antihypertensive drug verapamil and an analogue. A particularly mild ruthenium-catalyzed direct hydroamidation of the intermediate olefin in this synthesis is also reported.
一种基于醋酸钯和三（5-氟-2-甲基苯基）膦（F-TOTP）混合物的新型催化体系已被设计用于烷烃链段的分子内C-H官能化反应。在三（2-甲基苯基）膦（P（o-tol）（3））的其他类似物中，F-TOTP被证明对该反应具有最佳的金属键合性能。该催化体系在较温和的反应条件下运行，能够区域选择性地生成与季苄基碳原子相邻的各种烯烃以及新型的双环和三环分子。提出了一种通用机理，即在氧化加成和环钯化后优先形成六元钯（II）钯环。在抗高血压药物维拉帕米及其类似物的合成中展示了将烷基区域选择性地C-H官能化为烯烃的过程。还报道了在该合成中对中间体烯烃进行的特别温和的钌催化直接加氢酰胺化反应。
