The reaction of 2-trimethylsiloxyphenyl isocyanide (1) with [M(CO) 5 (THF)] (M=Cr, W) gives the complexes [M(2-Me 3 SiO-C 6 H 4 NC)(CO) 5 ] (2) (2a, M=Cr; 2b, M=W). Hydrolysis of the Si-O bond leads to the formation of an equilibrium between complexes 3 (3a, M=Cr; 3b, M=W) with a 2-hydroxyphenyl isocyanide and complexes 4 (4a, M=Cr; 4b, M=W) with a 2,3-dihydrobenzoxazol-2-ylidene ligand. Deprotonation of mixtures 3/4 followed by alkylation with allyl bromide yields exclusively N-allyl-2,3-dihydrobenzoxazol-2-ylidene complexes (5) (5a, M=Cr; 5b, M=W). Thermally induced intramolecular substitution of one cis-carbonyl ligand in (N-allyl-2,3-dihydrobenzoxazol-2-ylidene)-pentacarbonyltungsten (5b) results in the formation of the alkene-carbene complex 6 incorporating an η 2 :η 1 -(N-allyl-2,3-dihydrobenzoxazol-2-ylidene) ligand. The molecular structure of 5b is reported.