Department of Chemistry & Chemical Biology, Harvard University , Cambridge, Massachusetts 02138, United States.
J Am Chem Soc. 2017 Jul 12;139(27):9152-9155. doi: 10.1021/jacs.7b05160. Epub 2017 Jun 29.
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.
在饱和碳骨架中呈 1,3-关系排列的电负性取代基由于偶极最小化效应可以对分子构象产生强烈影响。因此，将此类官能团关系纳入其中的简单通用方法可以为调节分子形状提供有价值的工具。在这里，我们描述了一种使用芳基碘 (I-III) 催化的环丙烷 1,3-氧化的通用策略，重点是 1,3-二氟化反应。这些反应利用实用的商业上可获得的试剂并可以参与各种取代的环丙烷底物。对几种产物的晶体和溶液结构的分析揭示了 1,3-二氟化物在决定分子构象方面的一致影响。通过催化氧化开环环丙烷合成 1,3-氟乙酰氧基化产物、1,3-二醇、1,3-氨基醇和 1,3-二胺，证明了 1,3-氧化策略的通用性。
