Studies carried out to further develop tin-catalyzed transcarbamoylation reactions demonstrated that transcarbamoylation of cinnamyl alcohol in the context of allyl cyanate-to-isocyanate rearrangement can be efficiently carried out on a ten-gram scale and that tin-catalyzed transcarbamoylation is a valuable alternative to the method using trichloroacetyl isocyanate. In addition, methyl carbamate
A new approach to the synthesis of carbamates based on a tin-catalyzed transcarbamoylation process has been developed. Reactions of primary and secondary alcohols with phenyl carbamate in toluene at 90 °C proceed smoothly in the presence of tin-catalyst to generate the corresponding carbamates in good yields. This mild method exhibits a broad functional-group tolerance.
已经开发了一种基于锡催化氨基甲酰化过程合成氨基甲酸酯的新方法。伯醇和仲醇与氨基甲酸苯酯在 90 °C 的甲苯中在锡催化剂存在下顺利进行反应,以良好的产率生成相应的氨基甲酸酯。这种温和的方法表现出广泛的官能团耐受性。
Tethered Aminohydroxylation: Dramatic Improvements to the Process
作者:Timothy J. Donohoe、Carole J. R. Bataille、William Gattrell、Johannes Kloesges、Emilie Rossignol
DOI:10.1021/ol070430v
日期:2007.4.1
[reaction: see text] Changing the identity of the N leaving group on a hydroxylamine-based reoxidant gives a dramatic improvement to the tetheredaminohydroxylationreaction. Using OCOC6F5 as a leaving group means that only 1 mol % of osmium is required and yields as high as 98% can be obtained. Acyclic homoallylic alcohols were substrates considered too unreactive for effective use in the tethered