The tetratolylporphyrinato complex, (TTP)TiCl2, oxidatively couples lithium acetylide reagents (LiC drop CR; R = Ph, SiMe3) to 1,3-butadiyne products. The reduced Ti(II) fragment scavenges the diyne to form an eta(2)=complex involving pi-bonding to only one of the alkyne units, (TTP)Ti(1,2-eta(2)-RC drop C-C drop CR). Independent syntheses of the diyne complex starting from (TTP)-TiCl and (TTP)Ti(eta(2)-EtC drop CEt) confirm the composition of the pi-adduct. The lability of the butadiyne ligand in these Ti porphyrin complexes is readily demonstrated by displacement with pyridine. [GRAPHICS]