Synthesis of fluorenylidene‐ and 9‐alkylidene‐3,6‐dimethyl‐4,5‐diazafluorene compounds from 2,2′‐biarene‐3,3′‐diyl bis(triflate) by a palladium‐catalyzed domino process

A convenient synthesis of the fluorenylidene and the 4,5‐diazafluorenylidene moiety is described. The palladium‐catalyzed coupling of 6,6′‐dimethyl‐2,2′‐bipyrdine‐3,3′‐diyl bis(triflate) ( 2 ) with phenylacetylene leads to the 4,5‐diazafluorenylidene compound 4 as the major reaction product by an intramolecular cyclization. Under the same conditions biphenyl‐2,2′‐diyl bis(triflate) ( 6 ) gives the threefold coupling product 7 . The connectivity of 4 and 7 is confirmed by crystal structure analysis.