Amine-Induced Selective C-C Bond Cleavage of 2,2,2-Trifluoroethyl Carbonyls for the Synthesis of Ureas and Amides.

An efficient and selective transformation of 2,2,2-trifluoroethyl carbonyls into ureas/amides with amines is reported. This protocol allows the selective cleavage of the C-C bond of 2,2,2-trifluoroethyl carbonyls under transition metal-free and oxidant-free conditions, which is in contrast to the analogous C-F or C-CF3 bond functionalization. This reaction reveals the unexplored reactivity of 2,2,2-trifluoroethyl carbonyls and exhibits a broad substrate range and good functional group tolerance.

Three-Component Reactions of α-CF3 Carbonyls, NaN3, and Amines for the Synthesis of NH-1,2,3-Triazoles.

The development of methods for the assembly of 1,2,3-triazoles is an important topic due to the broad applications of this motif in various scientific fields. In this work, we demonstrate that the three-component assembly of α-CF3 carbonyls, NaN3, and amines was achieved for the selective construction of a variety of 5-amino NH-1,2,3-triazoles under transition-metal-free and open-air conditions. The method provides a general and operationally simple route to functionalized biologically important molecules including carbohydrates, nucleosides, and peptides and exhibits broad substrate scopes. We further demonstrate that the NH-1,2,3-triazoles can be smoothly converted to the regiospecific N-2 alkylated 1,2,3-triazole products. Mechanistic studies based on experiments and density functional theory calculations showed that this transformation proceeds via defluorination-initiated programmed substitution/cyclization/H-transfer to give the 4,5-difunctionalized captodative NH-1,2,3-triazole product.