用叔丁基二甲基硅烷基（TBDMS）和叔丁基二苯基硅烷基（TBDPS）基团对N-邻苯二甲酰壳聚糖进行区域选择性硅烷化反应。

Regioselective silylation of N-phthaloylchitosan with TBDMS and TBDPS groups.

作者信息

Binette Alain, Gagnon Jonathan

机构信息

Département de biologie, chimie et géographie, Université du Québec à Rimouski, 300, allée des Ursulines, Rimouski, Québec, Canada, G5L 3A1.

出版信息

Biomacromolecules. 2007 Jun;8(6):1812-5. doi: 10.1021/bm0610976. Epub 2007 May 8.

DOI:10.1021/bm0610976

PMID:17487971

Abstract

N-Phthaloylchitosan represents a key intermediate for the regioselective modification of chitosan in organic media. Chemoselective protection of primary alcohols on N-phthaloylchitosan was achieved with tert-butyldimethylsilyl (TBDMS) and tert-butyldiphenylsilyl (TBDPS) groups in imidazole/DMF and DMAP/pyridine. Influence of experimental conditions such as solvent, choice of base, stoichiometry, temperature, and time of reaction was studied regarding the degree of substitution (ds) of silyl groups. TBDMS groups allow higher ds than TBDPS groups. Higher reaction temperatures in different conditions led to lower ds and incomplete substitution. However, regioselective silylation of N-phthaloylchitosan was realized with ds up to 0.92 at room temperature. Silylated derivatives were characterized by elemental analysis, IR, and CP/MAS 13C NMR spectroscopies.

摘要

N-邻苯二甲酰壳聚糖是壳聚糖在有机介质中进行区域选择性修饰的关键中间体。在咪唑/二甲基甲酰胺（DMF）和4-二甲氨基吡啶（DMAP）/吡啶中，使用叔丁基二甲基硅烷基（TBDMS）和叔丁基二苯基硅烷基（TBDPS）基团实现了N-邻苯二甲酰壳聚糖上伯醇的化学选择性保护。研究了诸如溶剂、碱的选择、化学计量、温度和反应时间等实验条件对硅烷基取代度（ds）的影响。TBDMS基团比TBDPS基团具有更高的取代度。在不同条件下较高的反应温度导致较低的取代度和不完全取代。然而，在室温下实现了N-邻苯二甲酰壳聚糖的区域选择性硅烷化，取代度高达0.92。通过元素分析、红外光谱（IR）和交叉极化/魔角旋转13C核磁共振（CP/MAS 13C NMR）光谱对硅烷化衍生物进行了表征。