Direct Conversion of Internal Alkynes into α‐Iodoenones: One‐Step Collaborative Iodination and Oxidation

Abstract

Abstract The reaction of an internal alkyne with 2,6‐dichloropyridine N ‐oxide, a nucleophilic oxidant, and electrophilic N ‐iodosuccinimide (NIS) simultaneously enables the direct access to versatile α‐iodoenones. Electronically biased internal alkynes undergo the one‐step transformation with excellent regioselectivities and with practical Z / E ratios. In comparison to the related oxidative gold catalysis using pyridine N ‐oxides, this reaction employs NIS as the stoichiometric ynophile instead of the soft acidic noble metal catalyst and affords products featuring an additional versatile CI bond. Similar strategies for replacing ynophilic cationic gold(I) complexes in oxidative gold catalysis with likewise ynophilic stoichiometric electrophiles would enable the development of new synthetic methods. magnified image