Regioselective O-alkylations and acylations of polyphenolic substrates using a calix[4]pyrrole derivative
作者:Grazia Cafeo、Franz H. Kohnke、Luca Valenti
DOI:10.1016/j.tetlet.2009.04.128
日期:2009.7
The 10α,20α-bis(4-nitrophenyl)-calix[4]pyrrole 2 can act as a topologically selective protecting group in the O-alkylation and acylation of polyphenolic polycyclic aromatic compounds thanks to the regioselective formation of phenolate-type complexes. Remarkably, the host–guest interaction with the anionic reagents is sufficiently strong and kinetically slow to produce a high degree of selectivity.
由于酚盐型配合物的区域选择性形成,10α,20α-双(4-硝基苯基)-杯[4]吡咯2可以作为多酚多环芳族化合物的O-烷基化和酰化中的拓扑选择性保护基。值得注意的是,主体与客体之间与阴离子试剂的相互作用足够强,并且动力学上很慢,从而产生很高的选择性。