Mild and High-Yielding Molybdenum(VI) Dichloride Dioxide-Catalyzed Formation of Mono-, Di-, Tri-, and Tetracarbamates from Alcohols and Aromatic or Aliphatic Isocyanates
作者:Christian Stock、Reinhard Brückner
DOI:10.1002/adsc.201200303
日期:2012.8.13
to completion when 1 mol% of the catalyst was employed. Diols, triols, and tetraols reacted with monoisocyanates likewise, as did monofunctional alcohols and diisocyanates. These pairings furnished di-, tri-, tetra-, and dicarbamates, respectively. Reactants, which were poorly soluble in CH2Cl2 at room temperature required elevating the temperature and possibly choosing a higher-boiling solvent (ClCH2CH2Cl
二氯化钼(VI)二氧化钼(MoO 2 Cl 2)及其二甲基甲酰胺(DMF)络合物均催化将醇加成到异氰酸酯中,从而生成氨基甲酸酯。当以1mmol的比例工作时,使用0.1 mol%的催化剂,或以20 mmol的比例工作时仅100 ppm的条件下,大多数添加操作在室温下于20分钟内完成。当使用1摩尔%的催化剂时,立体阻碍的底物反应完全。二醇,三醇和四醇同样与单异氰酸酯反应,单官能醇和二异氰酸酯也是如此。这些配对分别提供了二氨基甲酸酯,三氨基甲酸酯,四氨基甲酸酯和二氨基甲酸酯。难溶于CH 2 Cl 2的反应物在室温下,需要升高温度,还可能选择沸点更高的溶剂(ClCH 2 CH 2 Cl,DMF)。将二醇添加到二异氰酸酯中也是可行的,如我们推测的那样得到聚氨基甲酸酯。