Synthesis of Sterically Congested Carbamates of Carbohydrates through Organic Base Catalysis
Synthesis of Sterically Congested Carbamates of Carbohydrates through Organic Base Catalysis
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DOI：
10.1055/s-0037-1612425
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发表时间：
2019-08-01
影响因子：
2.6
通讯作者：
Wang, Guijun
中科院分区：
文献类型：
--
作者：
Chen, Anji;Wang, Dan;Wang, Guijun
4，6-O-亚苄基缩醛保护的α-甲氧基-d-葡萄糖和d-氨基葡萄糖是合成碳水化合物衍生物和功能分子组件的有效构件。在本研究中，我们开发了一种以有机碱为催化剂，通过异氰酸酯与葡萄糖和氨基葡萄糖反应来合成C-3氨基甲酸酯衍生物的通用方法。在没有合适催化剂的情况下，氨基葡萄糖衍生物的C-3羟基经异氰酸酯处理后不能转化为相应的氨基甲酸酯。通过对几种有机碱催化剂的筛选，发现5.0mol%的1，8-二氮杂双环[5.4.0]Undec-7-ene(DBU)是氨甲酰化反应的有效催化剂。用目前的方法已经有效地合成了这两种空间拥挤的碳水化合物的烷基和芳基氨基甲酸酯衍生物的文库。
4,6- O -Benzylidene acetal protected alpha-methoxy d -glucose and d -glucosamine are useful building blocks for the syntheses of carbohydrate derivatives and functional molecular assemblies. In this research, we have developed a general method for the preparation of C-3 carbamate derivatives of densely functionalized glucose and glucosamine with isocyanates using organic bases as catalysts. Without a suitable catalyst, the C-3 hydroxy group of the glucosamine derivative could not be converted into the corresponding carbamates when treated with isocyanates. Several organic bases were screened as the catalysts for the reactions, and we discovered that 5.0 mol% of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was an effective catalyst for the carbamoylation reaction. A library of both alkyl and aryl carbamate derivatives of the two sterically congested carbohydrates have been effectively synthesized using the current method.