Herein, we report the development of a dual catalytic approach for the cross-coupling of nitriles with aryl- and aliphatic-bromides. A titanium­(III) catalyst is used to activate nitriles enabling their coupling with organobromides through a nickel catalyst. The Ni/Ti system efficiently prepared unsymmetrical ketones with good chemoselectivity and could selectively couple a bromide in the presence of other functionalizable handles.

α,β-Unsaturated amides are important building blocks and are key structural elements in a number of biologically active natural products. Despite their importance and prevalence, few methods exist to prepare conjugated amides directly and modularly. To address this gap, a titanium-promoted coupling of alkynes and isocyanates has been developed. The method is highly stereoselective, producing only the E isomer with good chemoselectivity and regioselectivity (>95/5), for unsymmetrical internal alkynes that contain a steric bias. The reactive titanacyclopentene intermediate formed from the coupling of the alkyne and isocyanate was additionally reacted with various electrophiles to access tetrasubstituted enamides.

No abstract

No abstract