Department of Chemistry, The Chinese University of Hong Kong Shatin, New Territories, Hong Kong SAR, China.
J Org Chem. 2013 Sep 6;78(17):8562-73. doi: 10.1021/jo401240k. Epub 2013 Aug 22.
Asymmetric synthesis of (R,R)- and (S,S)-1,8,9,16-tetrahydroxytetraphenylenes was achieved from starting material (2R,3R)-butane-2,3-diol and (2S,3S)-butane-2,3-diol respectively by utilizing a center-to-axis strategy. A series of crown ether compounds 20, 24, and 25 and their corresponding enantiomers derived from chiral tetrahydroxytetraphenylene were synthesized in enantiomerically pure forms. Enantiomeric recognition properties of these hosts toward l- and d-amino acid methyl ester hydrochloride were studied by the UV spectroscopy titration. The tetramer hosts (S,S,S,S,S,S,S,S)-20 and (R,R,R,R,R,R,R,R)-20 exhibited the best enantioselectivities toward L- and D-alanine methyl ester hydrochloride salt with K(L)/K(D) = 4.1 and KD/KL = 3.9, respectively. The new chiral macrocyclic hosts would further enrich the host-guest chemistry.
（R,R）-和（S,S）-1,8,9,16-四羟基四苯并对苯醌的不对称合成是分别从起始原料（2R，3R）-丁烷-2,3-二醇和（2S，3S）-丁烷-2,3-二醇出发，通过利用中心轴策略来实现的。一系列冠醚化合物 20、24 和 25 及其衍生自手性四羟基四苯并对苯醌的对应对映异构体以对映体纯的形式合成。通过紫外光谱滴定法研究了这些主体对 l-和 d-氨基酸甲酯盐酸盐的对映体识别特性。四聚体主体（S,S,S,S,S,S,S,S）-20 和（R,R,R,R,R,R,R,R）-20 对 L-和 D-丙氨酸甲酯盐酸盐表现出最佳的对映选择性，其 K（L）/K（D）分别为 4.1 和 KD/KL = 3.9。新的手性大环主体将进一步丰富主体-客体化学。
