Synthesis and Conformational Evaluation of <i>p</i>-<i>tert</i>-Butylthiacalix[4]arene-crowns
作者:Fijs W. B. van Leeuwen、Hans Beijleveld、Huub Kooijman、Anthony L. Spek、Willem Verboom、David N. Reinhoudt
DOI:10.1021/jo0401220
日期:2004.5.1
p-tert-butylthiacalix[4]arene afforded 1,3-dihydroxythiacalix[4]arene-monocrown-5 (3b), 1,2-alternate thiacalix[4]arene-biscrown-4 and -5 (4a,b), and 1,3-alternate thiacalix[4]arene-biscrown-5 and -6 (5a,b), depending on the metal carbonates and oligoethylene glycol ditosylates used. Starting from 1,3-dialkylated thiacalix[4]arenes, the corresponding bridging reaction gave 1,3-alternate, partial-cone, and cone conformers
对-叔丁基硫杂杯[4]芳烃的桥接得到1,3-二羟基硫杂杯[4]芳烃-单冠5(3b),1,2-交替硫杂杯[4]芳烃-双皇冠-4和-5(4a,b),以及1,3交替的硫杂杯[4]芳烃-双冠5和-6(5a,b),具体取决于所使用的金属碳酸盐和低聚乙二醇二甲苯磺酸盐。从开始1,3-二烷基化的硫杂杯[4]芳烃,相应的桥连反应得到1,3-互生,局部锥体,和锥形构象10 - 19,这取决于取代基。温度依赖性研究表明,构象上灵活的1,3-二甲氧基硫杂杯[4]芳烃冠10a− c仅占据1,3-交替的构象。脱甲基只产生了1,3,2-二羟基硫杂杯[4]芳烃冠(3a,c),这是无法直接桥接噻[4]芳烃获得的。在几个X射线晶体结构和广泛的2-D 1 H NMR研究的基础上分配了不同的结构。