Metal-catalyzed acyl transfer reactions of enol esters: Role of Y₅(OⁱPr)₁₃O and (thd)₂Y(OⁱPr) as transesterification catalysts

(equation presented) Primary and secondary alcohols react with vinyl or isopropenyl acetate at room temperature in the presence of catalytic amounts (0.05-1 mol %) of Y₅(OⁱPr)₁₃O to give the corresponding esters. In selected cases, the yttrium catalyst promotes the selective O-acylation of amino alcohols without the formation of the amide. Enol esters also react with α-amino acid esters in the absence of a catalyst, at room temperature, to give the corresponding amides.