2-Halomethyleneoxetanes from 2-Methyleneoxetanes by Reaction with <i>N</i>-Halosuccinimides: Reactant Influences on Stereochemical Outcomes and Reaction Pathways

The first general synthesis of 2-halomethyleneoxetanes, realized by the reaction of 2-methyleneoxetanes with <i>N</i>-halosuccinimides (NXS), is reported. The relative diastereoselectivities of the transformations were dependent on the halogen of NXS, while alternative reaction outcomes were influenced by substituents on the oxetane. Quantum mechanical calculations and molecular dynamics simulations exploring the basis of the observed diastereoselectivities are described. These highly strained heterocycles underwent standard cross-coupling reactions, demonstrating their utility as synthetic intermediates.