base and ligand free copper catalyzed method for the construction of trifluoromethylated benzoxazines has been developed by using Umemoto's reagent. It involves the oxidative difunctionalization of alkenes through tandem C–O and C–CF3 bond formations. Furthermore, synthesized benzoxazines were selectively converted into trifluoromethylated allylic and (E)-vinylic benzamides by the treatment of KOtBu
通过使用梅本试剂开发了一种简单的无碱和无配体铜催化的三氟甲基化苯并恶嗪的构建方法。它涉及通过串联的C–O和C–CF 3键形成烯烃的氧化双官能团。此外,通过分别处理KO t Bu和CH 3 Li,将合成的苯并恶嗪选择性地转化为三氟甲基化的烯丙基和(E)-乙烯基苯甲酰胺。
Efficient synthesis of SCF<sub>3</sub>-substituted tryptanthrins by a radical tandem cyclization
作者:Jincheng Guo、Yanan Hao、Gang Li、Ziwen Wang、Yuxiu Liu、Yongqiang Li、Qingmin Wang
DOI:10.1039/d0ob00233j
日期:——
we report a new, efficient and atom-economical strategy for the synthesis of SCF3-substituted tryptanthrin derivatives. These previously unreported derivatives were obtained by means of a radical tandem cyclization. The reaction was triggered by addition of a SCF3 radical to a carbon-carbon double bond and involved the formation of a C(sp3)-SCF3 bond, a C(sp2)-C bond, and a C(sp2)-N bond. This method
Experimental and Computational Studies on Cp*<sup>Cy</sup>Rh(III)/KOPiv-Catalyzed Intramolecular Dehydrogenative Cross-Couplings for Building Eight-Membered Sultam/Lactam Frameworks
作者:Liping Li、Hui Gao、Ming Sun、Zhi Zhou、Wei Yi
DOI:10.1021/acs.orglett.0c01823
日期:2020.7.17
is an unusual Cp*CyRh(III)-catalyzed intramolecular site-specific aryl C–H annulation, a highly chemoselective protocol providing direct access to eight-membered sultams/lactams with broad substrate/functional group tolerance. Experimental and computational studies reveal that such a transformation involves a unique PivOH-assisted aryl C–H activation/alkene insertion/β-H elimination/hydrogen-transfer
A copper-catalyzedC(sp3)–H bondfunctionalization of simple alkanes with olefinic amides was developed for the efficient synthesis of important benzoxazine derivatives. It involves new C-C and C-O bondformation in one step via radical cascade process.
A new, efficient, and practical radical cyclization of olefinic amides with ketones through α-C(sp3)–H functionalization in the presence of tert-butyl peroxybenzoate (TBPB) is described for the first time. This protocol assembles a wide range of pivotal and useful benzoxazines in good to excellent yields under mild, catalyst-free, ligand-free, and base-free conditions with wide functional group tolerance