Abstract

Seven OH-free and O-permethylated monofunctionalized calix[5]arenes carrying either additional methyl or tert-butyl groups are prepared following fragment condensation protocols. This strategy proves to be superior to previous approaches. Calix[5]arenes with free OH groups all adopt a cone conformation stabilized by a seam of hydrogen bonds at the lower rim. Post-condensation modifications, i.e., methylation of phenolic OH groups or functional group interconversions can also be achieved. Bulky tert-butyl groups are also found to stabilize the cone conformations of O-methylated compounds. These compounds offer versatile functional groups that make these concave molecules interesting building blocks for the synthesis of more sophisticated molecular architectures.

Seven OH-free and O-permethylated monofunctionalized calix[5]arenes carrying either additional methyl or tert-butyl groups are prepared following fragment condensation protocols. This strategy proves to be superior to previous approaches. Calix[5]arenes with free OH groups all adopt a cone conformation stabilized by a seam of hydrogen bonds at the lower rim. Post-condensation modifications, i.e., methylation of phenolic OH groups or functional group interconversions can also be achieved. Bulky tert-butyl groups are also found to stabilize the cone conformations of O-methylated compounds. These compounds offer versatile functional groups that make these concave molecules interesting building blocks for the synthesis of more sophisticated molecular architectures.

中文翻译：

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单官能杯[5]芳烃的合成

摘要

按照片段缩合方案，制备了七个带有额外的甲基或叔丁基的无OH和O-全甲基化的杯芳烃[5]芳烃。事实证明，此策略优于以前的方法。带有游离OH基的杯[5]芳烃均采用在下部边缘通过氢键接缝稳定的视锥构象。也可以实现缩合后修饰，即酚羟基的甲基化或官能团的相互转化。还发现大的叔丁基可稳定O的圆锥构象-甲基化的化合物。这些化合物提供了多功能的官能团，这些官能团使这些凹形分子成为合成更复杂的分子结构的有趣构建基块。

按照片段缩合方案，制备了七个带有额外的甲基或叔丁基的无OH和O-全甲基化的杯芳烃[5]芳烃。事实证明，此策略优于以前的方法。带有游离OH基的杯[5]芳烃均采用在下部边缘通过氢键接缝稳定的视锥构象。也可以实现缩合后修饰，即酚羟基的甲基化或官能团的相互转化。还发现大的叔丁基可稳定O的圆锥构象-甲基化的化合物。这些化合物提供了多功能的官能团，这些官能团使这些凹形分子成为合成更复杂的分子结构的有趣构建基块。