Use of ruthenium alkylidenes in metathesis reactions

The linker free immobilization method was adopted for Zhan with different types of mesoporous molecular sieves having different architecture. The immobilized catalysts shown high activity in the metathesis reactions studied. The initial reaction rate increases with increasing pore size of the catalyst in RCM of citronellene, ADMET reaction of 1,9 decadiene and metathesis of 1-decene. Hoveyda-Grubbs type Zhan and Grubbs second generation catalysts immobilized on mesoporous molecular sieve SBA-15 proved to be highly active in cardanol metathesis, even without protecting OH groups. Zhan catalyst immobilized on SBA-15 was found to be more active than Grubbs second generation catalyst immobilized on SBA-15, however, its Ru leaching was higher in comparison with that of Grubbs second generation catalyst immobilized on SBA-15. Cardanol ethenolysis and cross metathesis with diacetoxybutene proceeded under mild conditions and very selectively to the products having applications as detergent precursors, flavor and fragrance agents. Low Ru leaching ensure the delivery of products of low contents of Ru residues.