Synthesis and Resolution of a Multifunctional Inherently Chiral Calix[4]arene with an ABCD Substitution Pattern at the Wide Rim: The Effect of a Multifunctional Structure in the Organocatalyst on Enantioselectivity in Asymmetric Reactions
作者:Seiji Shirakawa、Tomohiro Kimura、Shun-ichi Murata、Shoichi Shimizu
DOI:10.1021/jo8024412
日期:2009.2.6
synthetic route to inherently chiral calix[4]arenes with an ABCD substitution pattern at the wide rim in the cone conformation was developed for the first time. For the synthesis of inherently chiral ABCD-type calix[4]arenes, first 5,11-dibromo-17-(3,5-dimethylphenyl)-25,26,27,28-tetrapropoxycalix[4]arene (9) was prepared as a key intermediate. Then, functionalization of the calix[4]arene 9 was examined
首次开发了一种有效的合成路线,以固有的手性杯[4]芳烃在圆锥构象的宽边具有ABCD取代模式。为了合成固有手性ABCD型杯[4]芳烃,首先制备了5,11-二溴-17-(3,5-二甲基苯基)-25,26,27,28-四丙氧基杯[4]芳烃(9)作为关键的中间产物。然后,对杯[4]芳烃9进行功能化进行了检查,并通过溴基团的选择性单锂化实现了高度区域选择性的单官能化。用这种方法可以合成各种多功能的手性ABCD型杯芳烃[4]芳烃。因此,证明了ABCD型杯[4]芳烃固有的手性膦和羧酸衍生物的合成。另外,合成了在宽边缘具有3,5-二甲基苯基的ABCD型杯[4]芳烃的氨基苯酚衍生物1b,并将其拆分为光学纯的对映体。手性杯[4]芳烃1b在苯酚的不对称迈克尔加成反应中用作有机催化剂。3,5-二甲基苯基在杯[4]芳烃1b的宽边缘上的作用 考察了对映体对映体的对映体选择性,并观察到了3,5-二甲基苯基的积极作用。