BF₃·Et₂O-Catalyzed Direct Carbon−Carbon Bond Formation of α-EWG Ketene-(<i>S</i>,<i>S</i>)-Acetals and Alcohols and Synthesis of Unsymmetrical Biaryls

Abstract

A highly efficient BF3.OEt2-catalyzed formal dehydration C-C coupling reaction between readily available alpha-EWG ketene-(S,S)-acetals and various alcohols via direct substitution of the hydroxy group in alcohols has been developed. On the basis of this C-C coupling reaction, a series of alkylated alpha-EWG ketene-(S,S)-acetals and functionalized 1,4-pentanedienes were prepared in high to excellent yields and the unsymmetrical biaryls were synthesized in good yields from the generated 1,4-pentanedienes and nitroalkanes through a one-pot annulation-aromatization process.