Calix[5]arene Through-the-Annulus Threading of Dialkylammonium Guests Weakly Paired to the TFPB Anion

被引：21

作者：

De Rosa, Margherita ^{[1
]}

Talotta, Carmen ^{[1
]}

Gaeta, Carmine ^{[1
]}

Soriente, Annunziata ^{[1
]}

Neri, Placido ^{[1
]}

Pappalardo, Sebastiano ^{[3
]}

Gattuso, Giuseppe ^{[2
]}

Notti, Anna ^{[2
]}

Parisi, Melchiorre F. ^{[2
]}

Pisagatti, Ilenia ^{[2
]}

机构：

[1] Univ Salerno, Dipartimento Chim & Biol A Zambelli, Via Giovanni Paolo 2 132, I-84084 Salerno, Italy

[2] Univ Messina, Dipartimento Sci Chim Biol Farmaceut & Ambientali, Viale F Stagno dAlcontres 31, I-98166 Messina, Italy

[3] Univ Catania, Dipartimento Sci Chim, Viale A Doria 6, I-95125 Catania, Italy

来源：

JOURNAL OF ORGANIC CHEMISTRY | 2017年 / 82卷 / 10期

关键词：

SWITCHABLE ORGANOCATALYST; INTERLOCKED MOLECULES; SOLVENT-EXTRACTION; ALKYLAMMONIUM IONS; PROTON-TRANSFER; INDUCED-FIT; COMPLEXATION; ROTAXANE; RECOGNITION; HOST;

D O I：

10.1021/acs.joc.7b00406

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Through-the-annulus threading of calix[5]arene penta-O-ethers by dialkylammonium cations coupled to the loosely coordinating superweak TFPB- anion has been achieved. H-1 NMR titration data show that preorganization of the calix[5]arene scaffold leads to great thermodynamic stability of the pseudorotaxane complexes as well as to a favorable threading kinetic. Thus, calix[5]arene 1c, bearing tert-butyl groups at the wide rim, was threaded by all of the cations under study (with the exception of the dibenzylammonium 2b(+)) more tightly than the other derivatives under investigation (K-a's up to 2.02 +/- 0.2 x 10(5) M-1) because of its preorganized cone conformation. According to DFT calculations, van der Waals interactions between the tert-butyl groups of 1c and the alkyl chain of the cationic axle are likely responsible for the remarkable stability observed. The threading of the calix[S]arene wheels with the asymmetric pentylbenzylammonium axle 2c(+) led to the toposelective formation of the endo-pentylpseudorotaxane stereoisomer in agreement with the known "endo-alkyl rule". Owing to the steric hindrance of the axle phenyl group, the threading of the guest was seen to occur in a unidirectional fashion through the calixarene narrow rim.

引用

页码：5162 / 5168

页数：7