Synthesis of β-CF3 β-Amino Esters with an Indane Backbone by Rhenium-Catalyzed [3+2] Annulation.

The [3+2] annulation of trifluoromethylated ketimines with acrylates has been enabled by rhenium-catalyzed C-H activation, delivering a variety of β-CF3 β-amino esters. The reaction has exhibited broad substrate generality regarding aromatic CF3-ketimines and acrylates, the ability for gram scale synthesis, and facile derivation of the annulation products. The transformation is one of the few examples in which challenging sp2 C-H bonds of CF3-ketimines have been functionalized. The rapid assembly of biologically important fluorinated β-amino esters by this strategy will benefit the related studies and inspire a new approach for fluorinated motif synthesis.