Smiles rearrangement, carbonyl

A new multi-component Ugi-Smiles coupling reaction of heteroaromatic phenols (pyridines and pyrimidines) 151 with carbonyl compounds 152, amines 153 and isocyanides 154 involves a Smiles rearrangement to form a library of heterocyclic scaffolds 155. The first Ugi-Smiles conversion of thiols 156 was also performed. The reaction of 156 with a carbonyl compound, an amine and an isocyanide afforded the desired product 157 at 80 °C. 

The carboxylic acid 163 underwent an initial loss of water and in situ Smiles rearrangement involving S—>N migration to afford the ketone 167. The reaction of 163 with l,r-carbonyldiimidazole (CDI) resulted in the formation of 164, which then underwent intramolecular nucleophilic substitution by the sulfur atom at the activated 7V-carbonyl carbon of 164 to give the intermediate 165. Subsequent displacement afforded 166, which finally on ring contraction gave 167. ... 

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