Total synthesis of calothrixins A and B by palladium-catalyzed tandem cyclization/cross-coupling reaction of indolylborate

摘要

The palladium-catalyzed tandem cyclization/cross-coupling reaction of triethyl(indol-2-yl)borate with vinyl bromide was successfully used in the concise total synthesis of the indolophenanthridine alkaloids, calothrixins A and B. Palladium-catalyzed cross-coupling reaction of indolylborate with vinyl bromide proceeded smoothly, leading to triene. This intermediate was successfully used for the total synthesis of calothrixins A and B.