Unprecedented Direct Oxygen Atom Transfer from Hypervalent Oxido-λ<sup>3</sup>-iodanes to α,β-Unsaturated Carbonyl Compounds: Synthesis of α,β-Epoxy Carbonyl Compounds
Tetra-n-butylammonium oxido-lambda(3)-iodane, prepared from 1-hydroxy-1,2-benziodoxol-3(1H)-one by reaction with tetra-n-butylammonium fluoride, directly undergoes oxygenatom transfer to alpha,beta-unsaturated carbonylcompounds, yielding epoxides.
An enantioselective epoxidation of α-substituted vinyl ketones was realized to construct the key epoxide intermediates for the synthesis of various triazole antifungal agents. The reaction proceeded efficiently in high yields with good enantioselectivities by employing a chiral N,N′-dioxide/ScIII complex as the chiral catalyst and 35% aq. H2O2 as the oxidant. It enabled the facile transformation for
实现了α-取代乙烯基酮的对映选择性环氧化,构建了合成各种三唑类抗真菌剂的关键环氧化物中间体。通过使用手性N,N'-二氧化物/Sc III配合物作为手性催化剂和 35% 的水溶液,该反应以高产率和良好的对映选择性有效进行。H 2 O 2作为氧化剂。它使光学活性艾沙康唑、依氟康唑和其他潜在的抗真菌剂的转化成为可能。