A Fluorobenzene Adduct of Ti(IV), and Catalytic Carboamination to Prepare α,β-Unsaturated Imines and Triaryl-Substituted Quinolines

A rare fluorobenzene adduct of group 4, [(nacnac)TiNAr(FC<sub>6</sub>H<sub>5</sub>)][B(C<sub>6</sub>F<sub>5</sub>)<sub>4</sub>] (nacnac- = [ArNC(<i><sup>t</sup></i><sup></sup>Bu)]<sub>2</sub>CH, Ar = 2,6-<i><sup>i</sup></i><sup></sup>Pr<sub>2</sub>C<sub>6</sub>H<sub>3</sub>), has been isolated and structurally characterized. This highly electron-deficient system engages readily in imine metathesis and catalyzes carboamination reactions involving diphenylacetylene and aldimines to afford α,β-unsaturated imines as well as triaryl-substituted quinolines. The latter product results from cyclization of the corresponding electron-rich α,β-unsaturated imine.