Gold-catalyzed cycloaddition reactions of ethyl diazoacetate, nitrosoarenes, and vinyldiazo carbonyl compounds: synthesis of isoxazolidine and benzo[b]azepine derivatives.

Gold-catalyzed cycloadditions of ethyl diazoacetate, nitrosoarenes, and vinyldiazo carbonyl species to yield isoxazolidine derivatives stereoselectively are described. Treatment of these isoxazolidine products with the same catalyst results in a novel 1,2-H shift/[3,3] rearrangement to give benzo[b]azepine compounds. The mechanism of this skeletal rearrangement is elucidated with deuterium-labeling experiments.