Synthesis of 2,3-disubstituted indoles by radical cyclization with hypophosphorous acid and its application to total synthesis of (′)-catharanthine

Radical cyclization of o-alkenylthioanilides using hypophosphorous acid and AIBN in the presence of Et 3 N proceeded smoothly to furnish the corresponding 2,3-disubstituted indoles in high yields. Utilizing the newly developed cyclization condition, a stereocontrolled total synthesis of (′)-catharanthine has been completed.