Department of Chemistry, Stanford University, Stanford, California 94305, United States.
Biomacromolecules. 2012 Aug 13;13(8):2483-9. doi: 10.1021/bm300718b. Epub 2012 Jul 31.
The ring-opening polymerization of substituted cyclic carbonates with 1-(3,5-bis-trifluoromethyl-phenyl)-3-cyclohexyl-thiourea (TU)/1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) organocatalysts afford highly functionalized oligocarbonates. The fluorescent alkaloid quinine can be readily incorporated into the oligocarbonates either by initiation from quinine or by ring-opening polymerization of a quinine-functionalized cyclic carbonate (MTC-Q). Copolymerization of MTC-Q with a boc-protected guanidinium cyclic carbonate affords, after deprotection, highly water-soluble cationic copolymers functionalized with both quinine and pendant guanidinium groups. When multiple quinine groups are attached to the oligomers, they exhibit minimal fluorescence due to self-quenching. Upon hydrolysis, the fluorescence intensity increases, providing a potential strategy for monitoring the hydrolysis rates in real time.
用 1-(3,5-双三氟甲基-苯基)-3-环己基硫脲 (TU)/1,8-二氮杂二环[5.4.0]十一碳-7-烯 (DBU) 有机催化剂开环聚合取代环状碳酸酯，可得到高功能化的低聚物碳酸酯。荧光生物碱奎宁可以很容易地通过奎宁引发或通过奎宁功能化环状碳酸酯 (MTC-Q) 的开环聚合引入低聚物中。MTC-Q 与 Boc 保护的胍基环状碳酸酯共聚，然后脱保护，得到高度水溶性的阳离子共聚物，其同时具有奎宁和侧挂胍基官能团。当多个奎宁基团连接到低聚物上时，由于自猝灭，它们的荧光强度最小。水解后，荧光强度增加，为实时监测水解速率提供了一种潜在的策略。
