Synthesis and Molecular Recognition of Spherand-type Calixarenes

1.精子型杯芳烃的合成研究以碱金属氢氧化物为碱，通过碱催化5，5‘-二叔丁基-2，2’-二羟基联苯与甲醛在二甲苯回流下的缩合反应，成功地合成了一系列含三个和四个联芳烃单元的羟基[1_n]间苯并芳烃。2.研究了球形杯芳烃和球形杯芳烃的亲电取代反应和酚氧基因的O-烷基化反应，以提高客体分子的结合能力。确定了O-取代基对构象异构性的影响。在酚氧基上引入更大的烷基应该会导致双芳烃单元中的OR基团不能彼此传递的情况。这意味着围绕Ar-Ar sigma键的旋转受到阻碍，每个双芳烃单元都固定在一定的构型中。例如，在c++…中更多的四种不同的非对映异构体，其中两个是手性的：a)所有联芳烃单元具有相同构型(RRRR或SSSS，D_4对称)的化合物；b)其中一个联苯单元的构型不同于其他三个单元(RRRR或SSSR)的化合物；c)(RSRS=SRSR)；或d)(RRSS=SSRR)。3)分子识别研究我们首次证明了通过与溴乙酸乙酯烷基化形成的球形和类杯芳烃的衍生物给出了对金属和铵离子具有良好的络合性能和有趣的立体化学的离子载体。这些化合物被发现具有球状和杯芳烃的组合性质。因此，与杯[6]芳烃和杯[8]芳烃中相同的官能化酚类单元相比，双芳烃单元的限制环构象可以提高金属离子结合的选择性。虽然到目前为止只得到了两个立体异构体，但烷基化条件和试剂的变化可能会导致具有D_3和D_4对称性的衍生物，这将成为更大的潜在主体分子(如手性识别)的有趣构建块。较少

1.The development of synthesis of sperand-type calixarenes We have succeeded to develop a convenient and selective synthesis of a series of hydroxy[1_n]metabiphenylophanes with three and four biarene units involving base-catalyzed condensation of 5,5'-di-tert-buty1-2,2'-dihydroxybiphenyl with formaldehyde under xylene reflux depending on the alkaline metal hydroxide as a base.2.Studies on reactivities and propcties Electrophilic aromatic substitution reactions and O-alkylation of phenolic oxygenes of the spherand-type calixarenes were studied in order to increase the binding abilities for the guest molecules. The influence of O-substituents on the conformational isomerism has been established. Introduction of larger alkyl groups on the phenolic oxygens should lead to a situation where the OR groups within a biarene unit cannot pass each other. That means the rotation around the Ar-Ar sigma-bond is hindered and each biarene unit is fixed in a certain configuration. For example, in the c … More ase of the tetramer four different diastereomers of which two are chiral should be expected : a)A compound in which all biarene units have the same configuration (RRRR or SSSS,D_4-symmetry) ; b)A compound in which the configuration of one biphenyl unit differs from that of the other three(RRRS or SSSR) ; c)(RSRS=SRSR) ; or d)(RRSS=SSRR).3.Studies on molecular recognitions We have demonstrated for the first time that the derivatives of the spherand-type calixarenes formed by alkylation with ethyl bromoacetate give ionophores with promising complexation properties for metals and ammonium ions and interesting stereochemistry. These compounds are found to have combined properties of both the spherands and the calixarenes. Thus the restricted ring conformation due to the biarene units may increase the selectivity in the binding of metal ions as compared to the same functionalized phenolic units in calix[6]arene and calix[8]arene. While to date only two stereoisomers have been obtained, variation of the alkylation conditions and reagents could lead to the derivatives with D_3-and D_4-symmetry, which will serve as interesting building blocks for larger potential host molecule such as chiral recognitions. Less