Polymer-supported silyl cyanide and silyl azide: Useful reagents for solid-phase applications

The support of a delicate reagent on a solid matrix allows for better and s afer handling of the reagent itself. Because we had an interest in silicon- based supported reagents(1) we turned our attention to a polymer-supported trialkylsilyl cyanide and trialkylsilyl azide starting from a commercially available trialkylsilane resin. The supported cyanide was obtained with exc ellent yield and proved to be shelf-stable. This supported reagent was reac ted with a series of aldehydes and ketones yielding the corresponding polym er-supported cyanohydrins in good-to-excellent yields. A stability study on a model cyanohydrin demonstrated that these supported intermediates also c an be stored for a prolonged time. For the last step, a cleavage strategy t hat could release either cyanohydrins or alpha-hydroxy esters was adopted. Finally, we prepared a polymer-supported trialkylsilyl azide, which also pr oved to be shelf-stable. (C) 2000 John Wiley & Sons, Inc.