Palladium-Catalyzed Intramolecular Hydroalkylation of Alkenyl- ?-Keto Esters, ?-Aryl Ketones, and Alkyl Ketones in the Presence of Me3SiCl or HCl
作者:Xiaoqing Han、Xiang Wang、Tao Pei、Ross A. Widenhoefer
DOI:10.1002/chem.200400459
日期:2004.12.17
palladium-catalyzed hydroalkylation, but rather served as a source of HCl, which presumably catalyzes enolization of the ketone. Identification of HCl as the active promoter of palladium-catalyzed hydroalkylation led to the development of an effective protocol for the hydroalkylation of alkyl 3-butenyl ketones that employed sub-stoichiometric amounts of 2, HCl, and CuCl2 in a sealed tube at 70 degrees C.
3-丁烯基β-酮酸酯或3-丁烯基α-芳基酮与催化量的[PdCl2(CH3CN)2](2)和化学计量的Me3SiCl或Me3SiCl / CuCl2在二恶烷中的反应温度为25-70摄氏度以高产率和高区域选择性生成2-取代的环己酮。该方案容许许多酯和芳基,并容许在烯丙基,烯醇,顺式和反式末端烯烃位置上的取代。原位NMR实验表明,氯硅烷并不直接参与钯催化的加氢烷基化反应,而是用作HCl的来源,推测是催化酮的烯醇化反应。