Transition-Metal-Free β‑C–H Bond Carbonylation of Enamides or Amides with a Trifluoromethyl Group as CO Surrogate for the Synthesis of 1,3-Oxazin-6-ones
journal contributionposted on 03.03.2017, 20:20 by Ping Song, Peng Yu, Jin-Shun Lin, Yiqun Li, Ning-Yuan Yang, Xin-Yuan Liu
A cascade β-C–H bond trifluoromethylation/C(sp3)–F bond activation/hydrolysis reaction of enamides with Togni’s reagent has been disclosed. This formal C–H bond carbonylation reaction utilizes the CF3 group as a CO surrogate to provide an efficient approach to 1,3-oxazin-6-ones in satisfactory yields. Furthermore, CF3-containing 1,3-oxazin-6-ones could also be accessed using this method by using alkenyl N-ethylamides involving the functionalization of one Csp2–H, one Csp3–H, one Csp2–H, and three Csp3–F bonds. The broad substrate scope of this method enables access to synthetically or pharmaceutically important compounds, which are difficult to access by known methods.