A variety of neutral arene-ruthenium-carbenes of type (arene)RuCl2(=C(NR)CH(2)CH(2)NR) have been used for the catalytic transformation of (Z)-3-methylpent-2-en-4-yn-l-ol into 2,3-dimethylfuran. The catalytic reaction takes place at 80 degrees C with mononuclear complexes III-V to afford the furan in similar to 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.
C1 UNIV RENNES 1,CHIM COORDINAT ORGAN LAB,URA CNRS 415,F-35042 RENNES,FRANCE.