polymers. These organocatalysts are able to promote the enantioselective aza-Henry reaction with good yields and enantioselection. The activity and stereoselectivity of those materials are dependent on the accessibility of the reactants to the active site, and they increase with the length of the tether connecting the thiourea and the biopolymer. The best catalyst can be recovered and recycled for
八种不同的可
生物降解的、具有双功能手性
硫脲的接枝
壳聚糖已被制备为一种更环保、更可持续的替代品,以替代那些以石化衍生聚合物为支撑的材料。这些有机催化剂能够以良好的产率和对映选择性促进对映选择性氮杂-亨利反应。这些材料的活性和立体选择性取决于反应物对活性位点的可及性,并且它们随着连接
硫脲和
生物聚合物的系链的长度而增加。最好的催化剂可以回收和循环使用5次而不会损失活性。