Effect of Tethered, Axially Coordinated Ligands (TACLs) on Dirhodium(II,II) Catalyzed Cyclopropanation: A Linear Free
Cristian Zavala1, Ampofo Darko1
1Department of Chemistry, University of Tennessee, 1420 Circle Drive, Knoxville, Tennessee 37996, United States.
Abstract:
Hammett correlation experiments were used to determine the influence of dirhodium(II,II) paddlewheel complexes with tethered, axially coordinated ligands (TACLs) on the selectivity of rhodium carbenoids in competitive cyclopropanation reactions. The results suggest that dirhodium(II,II) paddlewheel complexes with TACLs are less sensitive to changes in electronics and reduce selectivity in cyclopropanation reactions with acceptor-substituted rhodium carbenoids. Also, Hammett plots with aryl diazoacetates resulted in a nonlinear downward curvature, suggesting a change in the rate-limiting step of the carbene transfer reaction.
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