Ir-Catalyzed ring-opening of oxa(aza)benzonorbornadienes with water or alcohols

Abstract

A highly efficient Ir-catalyzed ring-opening reaction of oxa(aza)benzonorbornadienes with water was firstly developed, which afforded a mild access to substituted dihydronaphthalene products with excellent yields (up to 99%) within 30 min. Further studies showed that when we used proton containing nucleophiles such as alcohols, we obtained the corresponding trans-1,2-disubstituted dihydronaphthalenol products in excellent yields (up to 99%) within 30 min. In addition, these two reactions not only occurred with low catalyst loading (1 mol% for most substrates), but also led to the desired products in excellent yields in the absence of a bisphosphine ligand. Another interesting finding was that 1-naphthylamine 6 was synthesized through the aromatization reaction of ring-opening product 3f using Lewis acid BF₃·OEt₂ as a catalyst.