Studies On The α-Functionalization Reaction Of α-EWG Ketene-(S,S)-Acetals

α-Oxo ketene dithioacetals has become a kind of versatile intermediates used in organic synthesis during the past four decades. As the electron withdrawing effect of carbonyl andβ-bit dual-alkylthio strong electronic effects for the joint action, makingα-Oxo ketene dithioacetals carbon - carbon double bond a high degree of polarization. Therefore, theα-position has a strong nucleophilic, the ability to react with a variety of electrophilic reagents, synthetic compounds rich in a variety of functional groups, which are widely used in organic synthesis.In recent years, we have carried out some systematic research onα-functionalization reaction ofα-oxo ketene dithioacetals and then proposed the concept ofα-functionalization. In this paper, on the basis of previous work, we focuses on exploration of copper bromide as the bromide reagents and catalysts ofα- bromination reaction ofα-oxo ketene dithioacetals, as well as the coupling reaction betweenα-oxo ketene dithioacetals and alcohol, a specific study as follows:(1)Using low-cost and easy to deal CuBr2 as the bromide reagent at room temperature in THF in the presence of a little water,α-bromo ketene dithioacetals were prepared in high yields and high selectivity.(2) Under the cocatalysis of CuBr2/BF3-Et2O in the mild conditions (room temperature, 40℃, 80℃) , the coupling reaction ofα-oxo ketene dithioacetals and alcohol was achieved.