Ligand-Controlled Selectivity in the Desymmetrization of meso Cyclopenten-1,4-diols via Rhodium(I)-Catalyzed Addition of Arylboronic Acids
Frederic Menard, David Perez, Daniela Sustac Roman, Timothy M. Chapman and Mark Lautens*
*Davenport Research Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6, Canada, Email: mlautenschem.utoronto.ca
F. Menard, D. Perez, D. S. Roman, T. M. Chapman, M. Lautens, J. Org. Chem., 2010, 75, 4056-4068.
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A highly enantioselective Rh-catalyzed asymmetric allylic substitution allows the desymmetrization of meso cyclopent-2-ene-1,4-diethyl dicarbonates. Depending on the ligand, each of two regioisomeric products can be obtained in good yield and excellent enantioselectivity. Whereas bisphosphine P-Phos ligands form trans-1,2-arylcyclopentenols, Segphos ligands lead predominantly to trans-1,4-arylcyclopentenols.
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