Abstract
The efficient synthesis of oligosaccharides requires methods for regioselective manipulation of hydroxyl groups in monosaccharide derivatives. Catalysis represents a potentially general solution to this problem, and over the past decade, the development of catalyst-controlled methods for regioselective functionalization of carbohydrates has intensified. This Short Review highlights the range of catalysts and catalytic mechanisms that may be exploited to alter the reactivity of hydroxyl groups in carbohydrate substrates.
1 Introduction
2 Intrinsic Trends in the Reactivity of Carbohydrate Hydroxyl Groups
2.1 Steric Control
2.2 Electronic Control
3 Enzyme Catalysis
4 Phase-Transfer Catalysis
5 Lewis Base Catalysis
5.1 Peptide-Based Catalysts
5.2 Modified DMAP Catalysts
5.3 Chiral Amines
6 Lewis Acid Catalysis
6.1 Tin(IV) Reagents
6.2 Transition-Metal Reagents
6.3 Lanthanum(III) Reagents
6.4 Multistep One-Pot Methods
6.5 Organoboron Reagents
7 Conclusions and Outlook
Key words
carbohydrates - Lewis acid catalysis - Lewis base catalysis - protecting groups - regioselectivity
