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.

沿饱和碳骨架以1,3-位关系排布的电负性取代基，可通过偶极最小化效应对分子构象产生强烈影响。因此，构建此类官能团排布关系的简洁通用方法，将为调控分子构型提供极具价值的工具。本文报道一种基于芳基碘(I–III)催化的环丙烷1,3-氧化通用策略，重点关注1,3-二氟化反应。该反应使用实用的市售试剂，可兼容多种取代环丙烷底物。对部分产物的晶体及溶液结构分析表明，1,3-二氟取代基对分子构象具有一致的调控效应。通过环丙烷的催化氧化开环反应合成1,3-氟乙酰氧基化产物、1,3-二醇、1,3-氨基醇及1,3-二胺类化合物，验证了该1,3-氧化策略的普适性。