Copper-catalyzed diboration of ketones: facile synthesis of tertiary alpha-hydroxyboronate esters.
The diboration of ketones with the (ICy)CuOt-Bu catalyst was developed to provide access to tertiary alpha-hydroxyboronate esters. The (ICy)CuOt-Bu catalyst was generated in situ with (ICy)CuCl and NaOt-Bu to afford a more efficient catalyst than the preformed (ICy)CuOt-Bu. These conditions result in the diboration of various ketones in toluene at 50 degrees C in 2-22 h. Treatment of the resulting products with silica gel affords the corresponding alpha-hydroxyboronate esters.
McIntosh
Melissa L
ML
Department of Chemistry, Western Washington University, 516 High Street, Bellingham, Washington 98225, USA.
Moore
Cameron M
CM
Clark
Timothy B
TB