Zhu Chuanle, Zeng Hao, Liu Chi, Chen Fulin, Jiang Huanfeng
Key Laboratory of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering , South China University of Technology , Guangzhou 510640 , P. R. China.
Org Lett. 2019 Jun 21;21(12):4900-4904. doi: 10.1021/acs.orglett.9b01817. Epub 2019 Jun 12.
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(sp)-H bond by an internal oxdative C(sp)-H functionalization strategy. Preliminary investigations revealed that α,β-unsaturated ketoxime acetates were an internal oxidant, and the in situ generated HO served as the O-source of the carbonyl oxygen in the product.
铜催化的α,β-不饱和酮肟乙酸酯与三氟甲基酮的非对映选择性[4+2]环化反应能够顺利地生成各种3-三氟甲基化的3-羟基环己烷-1-酮。该反应的特点是通过内部氧化C(sp)-H官能团化策略对酸性较弱的C(sp)-H键进行选择性官能团化。初步研究表明，α,β-不饱和酮肟乙酸酯是一种内部氧化剂，原位生成的HO作为产物中羰基氧的氧源。
