Gonera Antje, Goclik Vera, Baum Marita, Mischnick Petra
TU Braunschweig, Institut für Lebensmittelchemie, Schleinitzstrasse 20, D-38106 Braunschweig, Germany.
Carbohydr Res. 2002 Nov 19;337(21-23):2263-72. doi: 10.1016/s0008-6215(02)00115-5.
O-aminopropyl starch was prepared by Michael addition of acrylonitrile and subsequent reduction with freshly prepared cobalt boride and sodium borohydride. In a second approach, the aminopropyl group was introduced via Williamson etherification with N-phthalyl-protected 3-bromo-1-propylamine. The protecting group was removed by borohydride reduction and subsequent hydrolysis in acetic acid. The DS of all samples and the degree of reduction of the cyanoethyl groups were estimated from the 1H NMR spectra. Total monomer composition was determined after methanolysis or hydrolysis and trimethylsilylation by GLC and GCMS. While the regioselectivity in the thermodynamically controlled reaction was O-6 > O-2 > O-3 (50:37:13), the kinetically controlled process showed strongly preferred O-2-etherification (up to 94%) followed by O-6- and O-3-substitution. It could be influenced by choice of solvent (water, Me(2)SO) and base (NaOH, Li-dimsyl).
通过丙烯腈的迈克尔加成反应，随后用新制备的硼化钴和硼氢化钠还原，制备了邻氨基丙基淀粉。在第二种方法中，通过与N-邻苯二甲酰保护的3-溴-1-丙胺进行威廉姆森醚化反应引入氨基丙基。通过硼氢化钠还原，随后在乙酸中水解除去保护基。根据1H NMR光谱估算所有样品的取代度（DS）和氰乙基的还原程度。通过甲醇解或水解以及气相色谱（GLC）和气相色谱 - 质谱联用（GCMS）进行三甲基硅烷化后，测定总单体组成。虽然在热力学控制反应中的区域选择性为O-6 > O-2 > O-3（50:37:13），但动力学控制过程显示强烈倾向于O-2-醚化（高达94%），随后是O-6-和O-3-取代。它可能受溶剂（水、二甲基亚砜）和碱（氢氧化钠、二甲基锂）的选择影响。
