Method of preparing trisubstituted ethylene compounds

A method of forming a trisubstituted ethylene compound, the method comprising:

• (A) providing a trisubstituted ethylene compound bearing a first substituent, a second substituent and a third substituent, in which the first substituent and the second substituent are bound to the one olefinic carbon atom, wherein said first substituent and said second substituent are different from one another, and wherein said third substituent is bound to the other olefinic carbon atom;
• (B) providing an olefin bearing at least a fourth substituent, which is bound to an olefinic carbon atom, wherein said fourth substituent is different from the third substituent of the trisubstituted ethylene compound provided in step (A);
• and wherein said olefin is a monosubstituted ethylene compound or a disubstituted ethylene compound in which the substituents are vicinally bound to the olefinic carbon atoms, optionally wherein the substituents are identical;
• (C) subjecting the trisubstituted ethylene compound provided in step (A) to a cross-metathesis reaction with the olefin provided in step (B) to form said trisubstituted ethylene, wherein the formed trisubstituted ethylene compound has one olefinic carbon atom from the trisubstituted ethylene compound provided in step (A), which bears said first substituent and said second substituent, and one olefinic carbon atom from the olefin provided in step (B), which bears said fourth substituent;
• wherein the cross-metathesis reaction is catalysed by a transition metal complex bearing ligands from which one ligand is a carbene ligand, wherein the metal complex is characterized by a M=C moiety, wherein M is the transition metal and C is the carbene carbon atom of the carbene ligand.