The intermolecular deacylative coupling of unstrained ynones via C–C bond activation was accomplished by a CuCl–bpy system under mild reaction conditions. This protocol features facile cleavage of the C–C bond at room temperature, broad substrate scope, and efficient construction of important symmetric and unsymmetrical 1,3-diyne adducts through homo or cross coupling of ynones, respectively. The preliminary mechanistic investigations indicated that an acyl copper­(III) complex is likely involved in this process.

Transition metal catalyzed [3 + 2] annulation of imines with double bonds via directed C-H activation offers a direct access to amino cyclic motifs. However, owing to weak coordination and steric hindrance, trifluoromethylated ketimines have been an unaddressed challenge for TM-catalyzed annulations. Here, a rhenium-catalyzed [3 + 2] annulation of trifluoromethylated ketimines with isocyanates via C(sp 2 )-H activation has been disclosed. This approach provides an efficient platform for rapid access to a privileged library of CF 3 -containing iminoisoindolinones and polyamides by utilizing challenging CF 3 -ketimines as the annulation component. The capability of gram scale synthesis, the post-functionalization of the cyclization adduct, the derivation of complex natural molecules and the facile synthesis of polyamides highlight a diversity of synthetic potential of the current methodology.

The [3+2] annulation of trifluoromethylated ketimines with acrylates has been enabled by rhenium-catalyzed C−H activation, delivering a variety of β-CF 3 β-amino esters. The reaction has exhibited broad substrate generality regarding aromatic CF 3 -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 sp 2 C−H bonds of CF 3 -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.T he assembly of fluorinated analogues of biological molecules, such as sugars, nucleosides, steroids, amino acids, and others, has become an emerging area for organic chemists (Scheme 1). 1 The growing concern should be mainly ascribed to substantially altered performances such as metabolic stability, binding affinity, solubility, and lipophilicity, compared to those of the parent counterparts, which are endowed by the unique properties of fluorine. In the case of fluorinated amino acids (F-AAs), they have four dimensions of important applications in biologically chemistry: (1) exhibiting important biologically properties such as antiviral and antitumor activities that lead to medical applications, (2)

The coupling between heterocycle N-oxides and CF3-ynones has been demonstrated via the formal C−H and C−C bond cleavage under catalyst-free and mild conditions. This reaction has displayed broad substrate scope...

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