Özet:
A variety of neutral arene-ruthenium-carbenes of type (arene)RuCl2(=C(NR)CH2CH2NR) have been used for the catalytic transformation of (Z)-3-methylpent-2-en-4-yn-1-ol into 2,3-dimethylfuran. The catalytic reaction takes place at 80°C with mononuclear complexes III-V to afford the furan in ~90% yield. The binuclear catalysts VIa and VIIa having a linked bis-carbene bridge operate at room temperature to initiate an exothermic reaction offering 90-97% of furan.