Facile formation of five-membered N-heterocyclic zirconacycloallenoidsElectronic supplementary information (ESI) available: Experimental details of the preparation and characterization of the compounds 9a-c, 10c, 11a,b and the NMR spectra for 11d-g. CCDC 875088, 875089, and 875090. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c2dt31343j

The reaction of 2 -iminozirconocene chloride complexes with trimethylsilylethynyl lithium leads to rapid C-C coupling at room temperature to yield the corresponding five-membered aza-zirconacycloallenoids. Such compounds were also obtained by trapping of in situ generated zirconocene with alkynyl imines. Reaction of 2 -iminozirconocene chloride complexes with trimethylsilylethynyl lithium yields the corresponding five-membered aza-zirconacycloallenoids, which were also obtained from in situ generated zirconocene with alkynyl imines.