乙酸促进邻甲基苯磺酸铜选择性催化醇和酚的四氢吡喃化反应

室温无溶剂条件下, 乙酸能有效促进邻甲基苯磺酸铜催化一系列醇或酚和3,4-2H-二氢吡喃反应, 生成相应的四氢吡喃醚. 在乙酸存在条件下, 体系的催化性能有显著提高, 邻甲基苯磺酸铜用量仅需0.3 mol%(占醇或酚的摩尔分数)就能使反应在较短时间内完成. 反应结束后, 邻甲基苯磺酸铜经简单相分离可多次重复使用, 催化活性无明显下降. 产物结构经IR, 1H NMR, 元素分析进行表征.

Chemoselective Tetrahydropyranylation of Alcohols and Phenols Catalyzed by Acetic Acid Assisted Copper o-Toluenesulfonate

Tetrahydropyranyl ethers were synthesized from corresponding alcohols or phenols and 3,4-dihydro-2H-pyran using acetic acid assisted copper o-toluenesulfonate as a synergistic catalyst at room temperature under a solvent-free condition. The catalytic activity of acetic acid assisted copper o-toluenesulfonate was much higher than that without acetic acid under the same conditions. Only the molar ratio 0.3 mol% of copper o-toluenesulfonate to alcohol or phenol was efficient to complete the reaction in a short time. After reaction, the copper o-toluenesulfonate could be recovered easily by simple phase separa-tion and reused many times without distinct loss of its catalytic activity. The structures of products were characterized by IR, 1H NMR spectra and elemental analysis.