Fraile, José M Theoretical insights into the role of a counterion in copper-catalyzed enantioselective cyclopropanation reactions. [electronic resource] - Chemistry (Weinheim an der Bergstrasse, Germany) Feb 2004 - 758-65 p. digital Publication Type: Journal Article ISSN: 0947-6539 Standard No.: 10.1002/chem.200305161 doi