Copper-Catalyzed Intermolecular [4 + 2] Annulation Enabled by Internal Oxidant-Promoted C(sp<sup>3</sup>)–H Functionalization: Access to 3-Trifluoromethylated 3-Hydroxy-cyclohexan-1-ones
作者:Chuanle Zhu、Hao Zeng、Chi Liu、Fulin Chen、Huanfeng Jiang
DOI:10.1021/acs.orglett.9b01817
日期:2019.6.21
A copper-catalyzed diastereoselective [4 + 2] cyclolization of α,β-unsaturated ketoxime acetates and trifluoromethyl ketones affords various 3-trifluoromethylated 3-hydroxy-cylcohexan-1-ones smoothly. This reaction features the selective functionalization of a less acidic C(sp3)–H bond by an internal oxdative C(sp3)–H functionalization strategy. Preliminary investigations revealed that α,β-unsaturated
铜催化的α,β-不饱和酮肟乙酸酯和三氟甲基酮的非对映选择性[4 + 2]环化可平稳地提供各种3-三氟甲基化的3-羟基-环羰基-1-酮。该反应的特征是通过内部氧化性C(sp 3)-H官能化策略对酸性较低的C(sp 3)-H键进行选择性官能化。初步研究表明,α,β-不饱和酮肟乙酸盐是一种内部氧化剂,原位生成的H 2 O用作产物中羰基氧的O源。