A Simple Synthesis of 2-Substituted-4H-3,1-benzoxazin-4-ones by Palladium-Catalyzed Cyclocarbonylation of o-Iodoanilines with Acid Chlorides
摘要:
One-pat reaction of o-iodoanilines with acid chlorides and carbon monoxide, in the presence of a palladium catalyst and diisopropylethylamine, regioselectively affords 2-substituted-4H-3,1-benzoxazin-4-ones in good to excellent yields. The reaction is believed to proceed via in situ amide formation from an o-iodoaniline and an acid chloride, followed by oxidative addition to Pd(0), CO insertion, and intramolecular cyclization to form the 2-substituted-4H-3,1-benzoxazin-4-one derivatives.