Introducing Catalytic Lossen Rearrangements: Sustainable Access to Carbamates and Amines
作者:Oliver Kreye、Sarah Wald、Michael A. R. Meier
DOI:10.1002/adsc.201200760
日期:2013.1.14
benign catalytic variant of the Lossen rearrangement is described. Dimethyl carbonate (DMC) as green activation reagent of hydroxamic acids in presence of catalytic amounts of tertiary amine bases 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (TBD), 1,8‐biazabicyclo 5.4.0 undec‐7‐ene (DBU), 1,4‐diazabicyclo[2.2.2]octane (DABCO), and triethylamine} and small quantities of methanol initiate the rearrangement. Methyl
描述了一种新的,高效且对环境无害的Lossen重排催化形式。碳酸二甲酯(DMC)在催化量的叔胺碱1,5,7-三氮杂双环[4.4.0] dec-5-ene(TBD),1,8-双氮杂双环5.4存在下作为异羟肟酸的绿色活化剂。 0十一碳烯(DBU),1,4-二氮杂双环[2.2.2]辛烷(DABCO)和三乙胺}和少量甲醇会引发重排。当脂族异羟肟酸用于催化Lossen重排时,氨基甲酸甲酯的收率中等至中等。在相同条件下,芳族异羟肟酸生成苯胺。值得注意的是,将DMC /甲醇的混合物再循环了几次,而没有观察到产率降低,从而使产生的废物最小化。而且,