A Highly Enantioselective Zirconium Catalyst for Intramolecular Alkene Hydroamination: Significant Isotope Effects on Rate and Stereoselectivity
作者:Kuntal Manna、Songchen Xu、Aaron D. Sadow
DOI:10.1002/anie.201006163
日期:2011.2.18
Zirconiumcatalysts sparkle: A new chiral zirconium complex has been used to catalyze hydroamination reactions to cyclize aminopentenes into 2‐methylpyrrolidines (see scheme). The rate law supports a mechanism involving a reversible substrate–catalyst interaction that precedes the rate‐determining step. A new mechanism for zirconium‐catalyzed hydroamination has been proposed based on kinetic isotope
Chiral Neutral Zirconium Amidate Complexes for the Asymmetric Hydroamination of Alkenes
作者:Mark C. Wood、David C. Leitch、Charles S. Yeung、Jennifer A. Kozak、Laurel L. Schafer
DOI:10.1002/anie.200603017
日期:——
Highly Enantioselective Zirconium-Catalyzed Cyclization of Aminoalkenes
作者:Kuntal Manna、William C. Everett、George Schoendorff、Arkady Ellern、Theresa L. Windus、Aaron D. Sadow
DOI:10.1021/ja4000189
日期:2013.5.15
Plots of initial rate versus [substrate] show a rate dependence that evolves from first-order at low concentration to zero-order at high concentration, and this is consistent with a reversible substrate-catalyst interaction preceding an irreversible step. Primary kinetic isotopeeffects from substrate conversion measurements (k'obs((H))/k'obs((D)) = 3.3 ± 0.3) and from initial rate analysis (k2((H))/k2((D))