Copper-catalyzed trifluoromethylation of alkenes: synthesis of trifluoromethylated benzoxazines

Abstract

A simple 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 KO(t)Bu and CH3Li, respectively.

Electrocatalytic Dehydrogenative Cyclization of 2-Vinylanilides for the Synthesis of Indoles

“…Data were reported as chemical shifts in ppm relative to TMS (0.00 ppm) for 1 H and CDCl 3 (77.2 ppm) for 13 C. High-resolution mass spectra (ESI) were recorded on an Agilent 6500 series Q-TOF. Sulfonamide substrates 1 , 4s , 6s , 8s , 9s , 15s , 16s , 17s , 18s , 21s , 22s , 23s are known compounds and prepared according the reported procedures.…”

Copper-Catalyzed Tandem Aerobic Oxidative Cyclization for the Synthesis of Polysubstituted Quinolines via C(sp3)/C(sp2)–H Bond Functionalization

“…13 C NMR (100 MHz,CDCl 3 ,ppm): δ = 144.4,142.3,140.3,131.0,130.2,129.34,129.25,128.4,128.2,127.1,122.8,121.3,117.1. Preparation of 1t. 19 To a stirred solution of Ph 3 PMeBr (1.5 equiv, 12.2 mmol) in dry THF (15 mL) was added KO t Bu (1.5 equiv, 12.2 mmol) in portions under nitrogen. After the mixture was stirred at room temperature for 0.5 h, a solution of the corresponding benzophenone (1 equiv, 8.14 mmol) in THF (15 mL) was added dropwise.…”

Iodine-mediated oxythiolation of o-vinylanilides with disulfides for the synthesis of benzoxazines

“…3–5 For example, benzo[ d ][1,3]oxazine, an essential heterocyclic skeleton which is widely found in natural products and biological active molecule, 6–10 could be synthesized by the intramolecular cyclization of N -(2-(1-phenylvinyl)phenyl)-benzamides (Scheme 1). 11–23 In the 1980s, Capozzi and co-workers synthesized methylthio-benzo[ d ][1,3]oxazine with this strategy for the first time, using Me 3 S 3 SbCl 6 as the methylthiolating agent (Scheme 1a). 19 Besides, this was the only way to generate this kind of compound for the next three decades.…”