Copper-catalyzed [1,2]-rearrangements of allylic iodides and aryl ?-diazoacetates.

ABSTRACT: The [1,2]- and [2,3]-rearrangements of iodonium ylides are synthetically useful reactions for the generation of functionalized ?-iodoesters. Allylic iodides are coupled with ?-diazoesters in the presence of a copper catalyst and a ligand to generate iodonium ylides, which undergo metal-mediated rearrangements. By fine-tuning the structure of the ligand, we have reversed the regioselectivity of copper-catalyzed reactions of iodonium ylides from [2,3]- to [1,2]-rearrangements with the use of alternate bipyridine ligands. The preference for [1,2]-rearrangements was further improved by using bulky aryl ?-diazoester substrates. Several ?-iodoesters with a diverse range of functional groups were generated in good yields (up to 88% yield) and high regioselectivities (up to >95:5 regioisomeric ratio). A deuterium-labeled substrate was utilized to gain insight into the mechanism of the reaction.

SUBMITTER: Xu B 

PROVIDER: S-EPMC5614460 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature