Catalytic 1,3-Difunctionalization via Oxidative C–C Bond Activation

Electronegative substituents arrayed
in 1,3-relationships along
saturated carbon frameworks can exert strong influence over molecular
conformation due to dipole minimization effects. Simple and general
methods for incorporation of such functional group relationships could
thus provide a valuable tool for modulating molecular shape. Here,
we describe a general strategy for the 1,3-oxidation of cyclopropanes
using aryl iodine­(I–III) catalysis, with emphasis on 1,3-difluorination
reactions. These reactions make use of practical, commercially available
reagents and can engage a variety of substituted cyclopropane substrates.
Analysis of crystal and solution structures of several of the products
reveal the consistent effect of 1,3-difluorides in dictating molecular
conformation. The generality of the 1,3-oxidation strategy is demonstrated
through the catalytic oxidative ring-opening of cyclopropanes for
the synthesis of 1,3-fluoroacetoxylated products, 1,3-diols, 1,3-amino
alcohols, and 1,3-diamines.