The first general method of direct and highly stereoselective Ti-mediated Mannich reaction between three types of simpleesters and E and Z mixtures of oxime ethers (aliphatic and aromatic) is accomplished.
ortho-Olefination of Arylaldehyde O-Methyloximes through Palladium-Catalyzed C-H Activation
作者:Zhipeng Xu、Biao Xiang、Peipei Sun
DOI:10.1002/ejoc.201200393
日期:2012.6
Palladium(II)-catalyzed ortho-olefination of arylaldehydeO-methyloximes by using O-methyloxime as a directing group gave 2-alkenylarylaldehyde O-methyloximes in moderate to good yields. After various reaction parameters (catalyst, oxidant, solvent, and reaction temperature) were examined, the optimal conditions for the reaction were identified. 2-Alkenylarylaldehydes could be obtained conveniently
通过使用 O-甲基肟作为导向基团,钯 (II) 催化芳基醛 O-甲基肟的邻-烯烃化反应以中等至良好的产率得到 2-烯基芳基醛 O-甲基肟。在检查了各种反应参数(催化剂、氧化剂、溶剂和反应温度)后,确定了反应的最佳条件。2-烯基芳醛可以通过偶联产物的水解方便地获得。提供了 C-H 键活化的动力学同位素效应 (kH/kD),并提出了反应的可能机制。
Pd-Catalyzed Multiple CH Functionalization to Construct Biologically Active Compounds from Aryl Aldoxime Ethers with Arenes
作者:Vedhagiri S. Thirunavukkarasu、Chien-Hong Cheng
DOI:10.1002/chem.201102996
日期:2011.12.23
Functional fluorenones: Aromatic aldoximeethers react with unactivated arenes catalyzed by palladium complexes to give biologicallyactive fluoren‐9‐ones (see scheme). MultipleCH bond activation and an oxidative cyclization are involved in the reaction.
Selective<i>ortho</i>-Bromination of Substituted Benzaldoximes Using Pd-Catalyzed C–H Activation: Application to the Synthesis of Substituted 2-Bromobenzaldehydes
Substituted 2-bromobenzaldehydes were synthesized from benzaldehydes using a three-step sequence involving a selective palladium-catalyzed ortho-bromination as the key step. O-Methyloxime serves as a directing group in this reaction. A rapid deprotection of substituted 2-bromobenzaldoximes afforded substituted 2-bromobenzaldehydes with good overall yields.