Metathesis Reactions for Monomer Synthesis

In SM and CM, combinations that lead to ethylene formation are often preferred (i.e., if the structures involved contain terminal unsaturations). This phenomenon is because easy removal of ethylene from the reaction medium contributes very effectively to achieve full conversion and/or a higher yield, compared with the cases where this situation is not possible. 

Stempfle and co-workers also used SM to synthesise the dimethyl-1,19-nonadecanedioate monomer from the methyl ester of high oleic sunflower oil. After 

Novel PA were prepared by polycondensation between diacids and diamines catalysed by l,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) in a very interesting study described by Meier and Mutlu [16]. In this study, unsaturated C20 chain PA with a Tm 180-226 °C were synthesised by polycondensation of the SM product of 10-undecenoic acid and various diamines. Fradet and colleagues studied various diamines (aliphatic, cycloaliphatic, benzylic) and used the same methodology [17, 18]. 

CM is also used in monomer synthesis from vegetable oils and their fatty acids. The increasing number of publications related to this subject over the last decade indicates its importance in the preparation of new molecules derived from renewable resources. 

In 2005, Patel and co-workers [19] undertook a set of CM reactions with sunflower, canola, linseed and soya oils and 2-butene using three ruthenium-based catalysts. Each of the vegetable oils gave excellent conversion to butenolysis products and high catalyst turnovers. Higher turnovers were obtained for oils containing predominantly oleic acid (e.g., sunflower oil) compared with those with higher proportions of polyunsaturated fatty acids (e.g., linseed oil). 

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