Ernst Schering Foundation Symposium Proceedings, Vol. 2, pp. 281–297
DOI 10.1007/2789_2008_080
© Springer-Verlag Berlin Heidelberg
Published Online: 30 April 2008
Organocatalysis by Hydrogen Bonding
Networks
A. Berkessel
(u)
Department of Chemistry, University of Cologne, Greinstraße 4, 50939 Cologne, Germany
email: berkessel@uni-koeln.de
1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
2
Case Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
2.1
Epoxidation and Baeyer–Villiger Oxidation with Hydrogen
Peroxide in Fluorinated Alcohol Solvents . . . . . . . . . . . . . . 283
2.2
Peptide-Catalyzed Asymmetric Epoxidation of Enones:
On the Mechanism of the Juliá–Colonna Reaction . . . . . . . . . 287
2.3
Enantiomerically Pure α- and β-Amino Acids from the Dynamic
Kinetic Resolution of Azlactones and the Kinetic Resolution
of Oxazinones . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
3
Epilogue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
Abstract. In biological systems, hydrogen bonding is used extensively for
molecular recognition, substrate binding, orientation and activation. In organocatalysis, multiple hydrogen bonding by man-made catalysts can effect remarkable accelerations and selectivities as well. The lecture presents four examples
of non-enzymatic (but in some cases enzyme-like!) catalysis effected by hydrogen bonding networks: epoxidation of olefins and Baeyer–Villiger oxidation of
ketones with H 2 O 2 in fluorinated alcohol solvents; peptide-catalyzed asymmetric epoxidation of enones by H 2 O 2 ; dynamic kinetic resolution of azlactones,
affording enantiomerically pure α-amino acids; and kinetic resolution of oxazinones, affording enantiomerically pure β-amino acids. All four types of transformations are of preparative value, and their mechanisms are discussed.
DOI 10.1007/2789_2008_080
© Springer-Verlag Berlin Heidelberg
Published Online: 30 April 2008
Organocatalysis by Hydrogen Bonding
Networks
A. Berkessel
(u)
Department of Chemistry, University of Cologne, Greinstraße 4, 50939 Cologne, Germany
email: berkessel@uni-koeln.de
1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
2
Case Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
2.1
Epoxidation and Baeyer–Villiger Oxidation with Hydrogen
Peroxide in Fluorinated Alcohol Solvents . . . . . . . . . . . . . . 283
2.2
Peptide-Catalyzed Asymmetric Epoxidation of Enones:
On the Mechanism of the Juliá–Colonna Reaction . . . . . . . . . 287
2.3
Enantiomerically Pure α- and β-Amino Acids from the Dynamic
Kinetic Resolution of Azlactones and the Kinetic Resolution
of Oxazinones . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
3
Epilogue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
Abstract. In biological systems, hydrogen bonding is used extensively for
molecular recognition, substrate binding, orientation and activation. In organocatalysis, multiple hydrogen bonding by man-made catalysts can effect remarkable accelerations and selectivities as well. The lecture presents four examples
of non-enzymatic (but in some cases enzyme-like!) catalysis effected by hydrogen bonding networks: epoxidation of olefins and Baeyer–Villiger oxidation of
ketones with H 2 O 2 in fluorinated alcohol solvents; peptide-catalyzed asymmetric epoxidation of enones by H 2 O 2 ; dynamic kinetic resolution of azlactones,
affording enantiomerically pure α-amino acids; and kinetic resolution of oxazinones, affording enantiomerically pure β-amino acids. All four types of transformations are of preparative value, and their mechanisms are discussed.