Organic Letters 2014-01-01

Stereoselective rearrangement of trichloroacetimidates: application to the synthesis of alpha-glycosyl ureas.

Yothin Teethaisong, Nongluk Autarkool, Kittipot Sirichaiwetchakoon, Pongrit Krubphachaya, Sajeera Kupittayanant, Griangsak Eumkeb

Index: Org. Lett. 11(11) , 2433-6, (2009)

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Abstract

A new method for the stereoselective synthesis of alpha-glycosyl ureas, via nickel-catalyzed [1,3]-rearrangement of glycosyl trichloroacetimidates, has been developed. The alpha-stereoselectivity at the anomeric carbon of the resulting trichloroacetamides depends on the nature of the cationic nickel catalyst. This method is applicable to a number of trichloroacetimidate substrates. The alpha-glycosyl trichloroacetamides can be directly converted into alpha-glycosyl ureas in the presence of amines. In all cases, the stereochemical integrity at the urea linkages remains intact.