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(FC6H5)][B(C6F5)4] (nacnac- = [ArNC(tBu)]2CH, Ar = 2,6-iPr2C6H3), 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 alpha,beta-unsaturated imines as well as triaryl-substituted quinolines. The latter product results from cyclization of the corresponding electron-rich alpha,beta-unsaturated imine.