Addition of (1-phenyl)ethenyl-amines H 2C=C(NR 2)Ph 2a,bto (1-alkynyl)carbene complexes (CO) 5M=C(OEt)C≡CPh 1a,b(M= W, Cr) affords 1-metalla-1,3,5-hexatrienes 4a-cin 90 –95%. Addition of N-[1-(cyclohex-1-enyl)]ethenyl-amines H 2)-(∼)C= CH(CH 2) 4∼ 2c,dto compounds 1a,byields novel 1-metalla-1,3,5,7 -octatetraenes (CO) 5M=C(OEt)-CH=C(Ph)-CH=C(NR-(∼)C=CH (CH 4d-fas major products together with a [4+2] cycloadduct 5das minor product. Compounds 4and 5have been fully characterized spectroscopically, compound 4dalso by X-ray analysis.