Organometallic macrocyclic chemistry. 6.1 Chelate-assisted macrocyclization of 4,7,10-trithiatrideca-2,11-diyne

The diyne 4,7,10-trithiatrideca-2,11-diyne (TTDD) reacts smoothly at room temperature with [Ru(CO)2(PPh3)3] to form [Ru(CO)(PPh3) {η4-S(C2H4SCCMe)2CO-κS}], a cyclopentadienone complex in which the unique sulfur atom is also coordinated to the metal but may be displaced by dppe to provide [Ru(CO)(dppe){η4-S(C2H4SCCMe)2CO }]. In contrast, 2,8-decadiyne fails to cyclize even at elevated temperatures, implicating thioether coordination in the mechanism of TTDD macrocyclization.