Event Information
Christopher F. Bender
(Duke University)
Au(I) and Pt(II) Catalyzed Hydroamination of C–C Multiple Bonds
Student Exams Seminar
Au(I) and Pt(II) Catalyzed Hydroamination of C–C Multiple Bonds
- Abstract:
- The hydroamination of secondary alkenyl amines catalyzed by a mixture of
[Pt(C2H4)Cl2]2 (2.5 mol%) and PPh3 (5 mol %) yielded pyrrolidines and a selected
piperidine derivative in moderate to good yield. C–N bond formation occurs via outersphere
attack of the pendant amine on a Pt-olefin complex, and the rate of the catalytic
process is limited by the intermolecular protonolysis of a Pt-alkyl intermediate. A
mixture of PtCl2 and P(t-Bu)2o-biphenyl was a more active catalyst system for the
hydroamination of secondary alkenyl amines allowing for an expanded substrate scope.
A mixture of Au[P(t-Bu)2o-biphenyl]Cl (5 mol %) and AgOTf (5 mol %) served as an effective catalyst for the intramolecular hydroamination of N-alkenyl carboxamides. A mixture of Au[PCy2(2′,6′-MeO-o-biphenyl)]Cl (5 mol %) and AgOTf (5 mol %) catalyzed the intramolecular exo-hydroamination of N-alkenyl ammonium salts. A cationic Au(I)-carbene catalyst generated in situ from Au(IPR)Cl and AgOTf catalyzed the cyclization of N-alkenyl ureas and carboxamides at room temperature.
The enantioselective hydroamination of achiral allenyl carbamates catalyzed by [(S)-3,5-t-Bu-4-MeO-MeOBIPHEP]Au2Cl2 and AgClO4 (5 mol %) yielded pyrrolidines in high yield with moderate to good enantioselectivities.
Ph.D. Defense Examination Seminar
Student Exams Seminar