Ernst Schering Foundation Symposium Proceedings, Vol. 2, pp. 45–124
DOI 10.1007/2789_2007_069
© Springer-Verlag Berlin Heidelberg
Published Online: 14 February 2008
Biomimetic Organocatalytic C–C-Bond
Formations
D. Enders
(u) , M.R.M. Hüttl, O. Niemeier
Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen,
Germany
email: Enders@rwth-aachen.de
1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2
Organocatalytic Approach Using Proline and Its Derivatives . . . . 47
2.1
Asymmetric Biomimetic C–C-Bond Formations
with a DHAP-Equivalent . . . . . . . . . . . . . . . . . . . . . . 47
2.2
Proline-Catalyzed Asymmetric Synthesis of Ulosonic Acid
Precursors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
2.3
First Direct Organocatalytic α-Fluorination of Aldehydes
and Ketones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
2.4
Asymmetric Organocatalytic Multicomponent Domino Reactions . 75
3
C–C-Bond Formations Employing N-Heterocyclic Carbene
Catalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
3.1
Enzymes as Archetypes . . . . . . . . . . . . . . . . . . . . . . . 82
3.2
The Benzoin Condensation . . . . . . . . . . . . . . . . . . . . . 83
3.3
The Stetter Reaction . . . . . . . . . . . . . . . . . . . . . . . . . 104
4
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Abstract. Mother Nature utilizes simple precursors to build up complex organic molecules efficiently. One important example is the C 3 building block
dihydroxyacetone phosphate, which is used in various enzyme-catalyzed reactions. Following this biosynthetic strategy the DHAP equivalent ‘dioxanone’
can be used in organocatalytic reactions to synthesize sugars, aminosugars, carbasugars, polyoxamic acids and sphingosines. In this respect, organocatalytic
domino reactions can also be seen as biomimetic as they are reminiscent of
DOI 10.1007/2789_2007_069
© Springer-Verlag Berlin Heidelberg
Published Online: 14 February 2008
Biomimetic Organocatalytic C–C-Bond
Formations
D. Enders
(u) , M.R.M. Hüttl, O. Niemeier
Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen,
Germany
email: Enders@rwth-aachen.de
1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2
Organocatalytic Approach Using Proline and Its Derivatives . . . . 47
2.1
Asymmetric Biomimetic C–C-Bond Formations
with a DHAP-Equivalent . . . . . . . . . . . . . . . . . . . . . . 47
2.2
Proline-Catalyzed Asymmetric Synthesis of Ulosonic Acid
Precursors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
2.3
First Direct Organocatalytic α-Fluorination of Aldehydes
and Ketones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
2.4
Asymmetric Organocatalytic Multicomponent Domino Reactions . 75
3
C–C-Bond Formations Employing N-Heterocyclic Carbene
Catalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
3.1
Enzymes as Archetypes . . . . . . . . . . . . . . . . . . . . . . . 82
3.2
The Benzoin Condensation . . . . . . . . . . . . . . . . . . . . . 83
3.3
The Stetter Reaction . . . . . . . . . . . . . . . . . . . . . . . . . 104
4
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Abstract. Mother Nature utilizes simple precursors to build up complex organic molecules efficiently. One important example is the C 3 building block
dihydroxyacetone phosphate, which is used in various enzyme-catalyzed reactions. Following this biosynthetic strategy the DHAP equivalent ‘dioxanone’
can be used in organocatalytic reactions to synthesize sugars, aminosugars, carbasugars, polyoxamic acids and sphingosines. In this respect, organocatalytic
domino reactions can also be seen as biomimetic as they are reminiscent of