Silylated Sugars – Synthesis and Properties

Silicon has been used in carbohydrate chemistry for half a century, but mostly as a protective group for sugar alcohols. Recently, the use of silicon has expanded to functionalization via C–H activation, conformational arming of glycosyl donors, and conformational alteration of carbohydrates. Silicon has proven useful as more than a protective group and during the last one and a half decades we have demonstrated how it influences both the reactivity of glycosyl donors and stereochemical outcome of glycosylations. Silicon can also be attached directly to the sugar C-backbone, which has even more pronounced effects on the chemistry and properties of the molecules. In this Account, we will give a tour through our work involving silicon and carbohydrates.1 Introduction2 Conformational Arming of Glycosyl Donors with Silyl Groups3 Silyl Protective Groups for Tethering Glycosyl Donors4. Si–C Glycosides via C–H Activation4.1 C–H Activation and Oxidation of Methyl 6-Deoxy-l-glycosides4.2 Synthesis of All Eight 6-Deoxy-l-sugars4.3 Synthesis of All Eight l-Sugars by C–H Activation4.4 Modification of the Oxasilolane Ring5 C–Si in Glycosyl Donors – Activating or Not?6 Si–C-Substituted Pyranosides7 Perspective