Regioselective Cross-Metathesis Reaction Induced by Steric Hindrance
Samir BouzBouz*, Rebecca Simmons and Janine Cossy*
*Laboratoire de Chimie Organique associé au CNRS, ESPCI, 10 rue Vauquelin, 75231 Paris Cedex 05, France, Email: samir.bouzbouzespci.fr, janine.cossyespci.fr
S. BouzBouz, R. Simmons, J. Cossy, Org. Lett., 2004, 6, 3465-3467.
Protection of hexa-1,5-dien-3-ol with bulky groups enables a regioselective cross-metathesis reaction at the C5-C6 double bond.
see article for more examples
A flame-dried round-bottomed flask was charged with diene (1 eq.), activated olefin (3 eq.) and dichloromethane (0.2 M). The Ru-catalyst (0.05 eq., 5 mol-%) was subsequently added as a solid, producing a light green solution which was stirred at 40 °C for 1 to 12 h depending on the substrate. The mixture was then concentrated in vacuo to a dark oil. This residue was purified on silica gel by flash chromatography (hexanes/ethyl acetate).
Acryloyl Chloride: An Excellent Substrate for Cross-Metathesis. A One-Pot Sequence for the Synthesis of Substituted α,β-Unsaturated Carbonyl Derivatives
L. Ferrié, S. Bouzbouz, J. Cossy, Org. Lett., 2009, 11, 5446-5448.