Regioselective double intramolecular bridging of p-tert-butylcalix[7]arene
作者:Marco Martino、Carmine Gaeta、Placido Neri
DOI:10.1016/j.tetlet.2004.03.028
日期:2004.4
The first examples of doubly bridged calix[7]arenes 2a–h have been obtained by base-promoted O-alkylation of p-tert-butylcalix[7]arene 1 or 1,4-tetramethylene-bridged calix[7]arene 3a with a variety of bis-electrophiles including BrCH2Cl, oligoethylene glycol ditosylates, and 1,2-bis(bromomethyl)benzene. In the presence of Cs2CO3 as the base, in acetone, the syn-1,4:2,3-bis-bridged regioisomer was
双桥联杯[7]芳烃的第一实施例2A - ħ已经通过的碱促进O-烷基化得到的p -叔-butylcalix [7]芳烃1或1,4-四亚甲基桥连的杯[7]芳烃3A与多种双亲电子试剂,包括BrCH 2 Cl,低聚乙二醇二甲苯磺酸盐和1,2-双(溴甲基)苯。在Cs的存在2 CO 3作为碱,在丙酮中,所述顺获得了-1,4:2,3-双桥区域异构体,产率高达76%。桥接模式的分配基于OH基团的化学位移以及与已知化合物的化学相关性。借助2D和动态NMR研究以及MM3计算研究了立体化学和构象特征。