Synthesis, NMR conformational studies and host–guest behaviour of new (+)-tartaric acid derivatives
作者:Sacha Legrand、Hannu Luukinen、Roland Isaksson、Ilkka Kilpeläinen、Mikael Lindström、Ian A. Nicholls、C. Rikard Unelius
DOI:10.1016/j.tetasy.2004.11.025
日期:2005.2
5-dimethanol TADDOLs has been prepared and host–guest interactions of these structures have been characterized using a series of 1H NMR studies. Enantioselective recognition of the chiral alcohols glycidol and menthol was observed for phenyl and 2-naphthyl derivatives. The influence of steric bulk on the dynamic fluxional behaviour of the TADDOL structures was demonstrated by dynamic NMR.
制备了一系列二聚体α,α,α',α'-四芳基-1,3-二氧戊环-4,5-二甲醇TADDOL,并使用一系列1 H NMR研究表征了这些结构的主客体相互作用。对于苯基和2-萘基衍生物,观察到手性醇缩水甘油和薄荷醇的对映选择性识别。通过动态NMR证实了空间体积对TADDOL结构的动态通量行为的影响。
Experimental and Theoretical Host–Guest Photochemistry; Control of Reactivity with Host Variation and Theoretical Treatment With a Stress Shaped Reaction Cavity; Mechanistic and Exploratory Organic Photochemistry 1,2
作者:Howard E. Zimmerman、Igor V. Alabugin、Valeriya N. Smolenskaya
DOI:10.1016/s0040-4020(00)00504-4
日期:2000.9
environment surrounding the reacting species. This made use of the recently developed Oniom computations of Gaussian98 which permit ab initio computations on the reacting species while performing molecular mechanical computations on the surrounding molecules. Included was determination of the effect of reaction cavity size. A new analysis, ‘Pairs’, was developed giving the specific important interactions
The novel, chiral, hostcompounds 8 and 9 were derivedfrom tartaric acid. Inclusion complexation with these hostcompounds permitted highly efficient resolution of some aliphatic alcohols (10−13). The symmetrical dimer hostcompound 8 is effective for optical resolution of alcohols 10, 12, and 13 by a combination of enantioselective inclusion complexation and distillation techniques. The unsymmetrical
A gold‐catalyzed asymmetriccyclopropanation of unactivated olefins with sulfoniumylides in the presence of a bimetallic catalyst with a novel dimeric TADDOL‐phosphoramidite ligand is reported. This transformation allows a rare gold‐catalyzed dynamic deracemization of chiral racemic substrates, where the same catalyst is responsible for several synergistic tasks in solution. The products are useful
Preparation, characterization and application of a stationary chromatographic phase from a new (+)-tartaric acid derivative
作者:Sacha Legrand、Harri Heikkinen、Ian A. Nicholls、Andrew Root、Johan Svenson、C. Rikard Unelius
DOI:10.1016/j.tetlet.2010.02.101
日期:2010.4
The preparation, characterization and application of a new stationary phase derived from 1,4-cyclohexanedione and diethyl (+)-tartrate are described. A suitable TADDOL for immobilization has been synthesized and grafted to a gamma-mercaptopropylsilylated silica gel. The resulting modified stationary phase has been characterized and its ability to separate enantiomers has been studied. While the free TADDOL in solution was able to resolve a range of enantiomers, the resolving properties were lost on immobilization. Solid state C-13 CPMAS NMR of the new stationary phase was used to explain the lack of stereoselective recognition. (C) 2010 Elsevier Ltd. All rights reserved.