Efficient and Selective Cu/Nitroxyl-Catalyzed Methods for Aerobic Oxidative Lactonization of Diols
作者:Xiaomin Xie、Shannon S. Stahl
DOI:10.1021/jacs.5b01036
日期:2015.3.25
unsymmetrical diols, whereas a Cu/TEMPO catalyst system (TEMPO = 2,2,6,6-tetramethyl-1-piperidinyl-N-oxyl) displays excellent chemo- and regioselectivity for the oxidation of less hindered unsymmetrical diols. These catalyst systems are compatible with all classes of alcohols (benzylic, allylic, aliphatic), mediate efficient lactonization of 1,4-, 1,5-, and some 1,6-diols, and tolerate diverse functional groups
Cu/硝酰基催化剂已被鉴定为在使用环境空气作为氧化剂的温和反应条件下促进二醇的高效和选择性有氧氧化内酯化。反应的化学选择性和区域选择性可以通过改变硝酰基助催化剂的特性来调节。Cu/ABNO 催化剂体系 (ABNO = 9-氮杂双环 [3.3.1]nonan-N-oxyl) 与对称二醇和受阻不对称二醇表现出优异的反应性,而 Cu/TEMPO 催化剂体系 (TEMPO = 2,2,6, 6-四甲基-1-哌啶基-N-氧基)对受阻较小的不对称二醇的氧化显示出优异的化学和区域选择性。这些催化剂体系与所有类型的醇(苄醇、烯丙基、脂肪醇)相容,介导 1,4-、1,5- 和一些 1,6-二醇的有效内酯化,并耐受不同的官能团,