Patent ID: 8097738

Claim:
A method of stereoselective cyclopropanation comprising the step of: combining a carbene precursor and an alkenyl substrate in the presence of a chiral catalyst to form a cyclopropyl product, the chiral catalyst being prepared in situ by the step of: combining an alkenyl ligand and a deprotonated chiral ligand in the presence of a ruthenium (II) metal; wherein the alkenyl ligand and the alkenyl substrate are each vinyl dihydrobenzofuran wherein the deprotonated chiral ligand is of formula (III): where R 1 and R 2 are each independently selected from the group consisting of hydrogen, substituted or unsubstituted C 1-8 alkyl, substituted or unsubstituted C 6-10 aryl, substituted or unsubstituted C 3-10 heterocyclyl, substituted or unsubstituted C 5-10 heteroaryl; where R 3 and R 4 are each independently selected from the group consisting of substituted or unsubstituted C 1-8 alkyl, substituted or unsubstituted C 3-8 cycloalkyl, C 1-10 alkoxy, C 1-12 alkylamino, substituted or unsubstituted C 3-10 heterocyclyl, substituted or unsubstituted C 6-10 aryl, substituted or unsubstituted C 5-10 heteroaryl and substituted or unsubstituted arylalkyl; where R 3 and R 4 together with the atoms to which they are attached may form a ring; and wherein M 1 and M 2 are each a counterion independently selected from the group consisting of Group I metal ions and Group II metal ions.