The reaction of 2‐alkynylanilines with KSeCN enabled by PhICl 2 in anhydrous MeCN was found to undergo an alternative pathway distinct from the previous report, furnishing 3,3′‐diindolyl selenides in moderate to good yield. The mechanistic studies support a cascade process involving the formation of the electrophilic selenocyanogen chloride from the reaction of PhICl 2 and KSeCN, electrophilic cyclization/selenocyanation of 2‐alkynylanilines to forge 3‐selenocyanato indole nuclei, followed by its further reaction with 2‐alkynylanilines to give the title 3,3′‐diindolyl selenides.
Zhao et al. (Fri,) studied this question.