Syntheses of New 1 → (2 + 1) <i>C</i>-Branched Monomers for the Construction of Multifunctional Dendrimers
作者:George R. Newkome、Hyung J. Kim、Charles N. Moorefield、Hima Maddi、Kyung-Soo Yoo
DOI:10.1021/ma034319q
日期:2003.6.1
four-directional core to produce the first-generation dendrimers (e.g., 9−11). The related second-generation dendrimer (15), possessing two different functional groups on both the surface and interior, was convergently synthesized from monomer 3. Alternatively, the mixed ester 17 was prepared starting with benzyl 4-nitrobutanoate (16); selective deprotection offered access to the representative 1 → (2 + 1)
为了提供通往多官能化树枝状聚合物的途径,设计并合成了具有酯和被保护的羟基或混合酯的新型1→(2 + 1)C-支链单体。因此,二-叔丁基4-(3- [X]氧丙基)-4- aminoheptanedioate(X =梅科,4 ; X = CH 2 CH 2 CN,6 ; X = CH 2 C ^ 6 ħ 5,7)是通过保护硝基前体2(X = H)制备高收率的化合物,这很容易从4-硝基丁醇与叔胺的迈克尔加成反应中获得丙烯酸丁酯,然后催化还原。这些单体容易附加到合适的四方向核心以产生第一代树枝状聚合物(例如,9 - 11)。从单体3聚合合成了相关的第二代树枝状聚合物(15),在表面和内部均具有两个不同的官能团。或者,以4-硝基丁酸苄酯(16)为起始原料制备混合酯17;和 选择性脱保护提供了对代表性的1→(2 +1)C支链单体20的访问,该单体已转化为树状聚合物29和30每个树突具有一个新的末端。这些1→(2