METATHESIS TRANSFORMATIONS OF NATURAL RUBBER: CROSS-METATHESIS OF NATURAL RUBBER WITH ESSENTIAL OILS USING RUTHENIUM ALKYLIDENE CATALYSTS

摘要: Natural rubber (NR) and essential oils are very attractive terpene based compounds. A wide variety of bio-based structures are synthesized by transformations of terpene units. The transformations of terpene based molecules using efficient catalysts are of great interest for the development of new applications for these biomass-derived compounds. In this perspective matathesis transformations are becoming more attractive as the availability and choice of effective catalysts increase. In this research we reported the cross-metathesis of NR with essential oils and monoterpenes such as d-limonene and β-pinene using ruthenium alkylidene catalysts the Hoveyda-Grubbs second generation [Ru (Cl2)(= CH (o-isopropoxyphenylmethylene))(1, 3-diphenyl-4, 5-dihydroimidazol-2-ylidene)(I), the Grubbs second generation (1, 3-diphenyl-4, 5-dihydroimidazol-2-ylidene)(PCy3) Cl2Ru= CHPh)(II) and the Grubbs first generation (PCy3) 2 (Cl) 2Ru= CHPh (III), and ruthenium vinylidene catalysts [RuCl2 (= C= HR)(PCy3) 2](R=-p-C6H4F (IV),-p-C6H4CF3 (V) and-C6H9 (VI). The isolated oligomer products with yields ranging from 94-96% and* arampmx@ unam. mx (A. Martínez).† Corresponding Author address: Institute of Materials Research, National Autonomous University of Mexico, PO Box 70-360, CU, Coyoacan, Cd. Mx. 04510, Mexico; Tel: 00 (52) 5556224586; Fax: 00 (52) 5556161201. Email: tma@ unam. mx.