Hydrozirconation of alkenes and alkynes, followed by insertion of 1-halo-1-lithio-1-alkenes, generated in situ by lithium tetramethylpiperidide deprotonation of vinyl halides, affords vinylzirconocene species which may be further elaborated. The method provides easy access to many structures including terminal (3E)- and (3Z)-1,3-dienes and (3E,5E)- and (3Z,5E)-1,3,5-trienes, and internal (E,Z)-dienes, (E,Z,E)-trienes, and (1E,3Z)-1,3-dien-5-ynes, Insertion of 2-monosubstituted 1-halo-1-lithio-1-alkenes occurs with clean inversion of configuration of the sp(2)-carbenoid carbon. Carbenoids derived by deprotonation of 2,2-disubstituted 1-halo-1-alkenes gave poor stereocontrol probably due to isomerization before insertion into the organozirconium species. Insertion of vinyl carbenoids into alkynylzirconocenes affords terminal (3E)- or (3Z)-1,3-dien-5-ynes, internal (1E,3Z)-1,3-dien-5-ynes, and (Z)-3-en-1,5-diynes.