Copper-Catalyzed Highly Selective Protoboration of CF3-Containing 1,3-Dienes.

The copper-catalyzed highly selective protoboration of CF 3 -containing conjugated diene with proton source and B 2 pin 2  has been developed. This chemistry could suppress the well-known defluorination and provide borated reagents with an intact CF 3 -group. Further studies indicated that the functional group tolerance of this chemistry is very well, and the products could be used as versatile precursors for different types of transformations. Importantly, using chiral diphosphine ligand, we have developed the first example for using such starting material to synthesis allylic boron-reagents which bearing a CF 3 -containing chiral center. Notably, the reaction mechanism was intensively studied by DFT calculation, which could reveal the reason that defluorination was inhibited.