A Convenient Synthesis of Fluoroalkylated Benzimidazole- or Indole-fused Benzoxazines

Fluoroalkyl group is of particular interest in pharmaceutical chemistry. Since benzimidazole- or indole-fused benzoxazines are important motifs in numerous biologically active molecules, the incorporation of a fluoroalkyl group into these molecules may provide more opportunities for drug developments. Herein we describe the first synthesis of fluoroalkylated benzimidazole- or indole-fused benzoxazines by using fluoroalkylated propiolates as building blocks. The reactions proceeded smoothly under mild conditions to give the desired products in moderate to high yields. Notably, benzimidazole-fused products were obtained by a convenient one-pot two-step process.