79349-04-5Relevant academic research and scientific papers
Chiroptical inversion induced by rotation of a carbon-carbon single bond: An experimental and theoretical study
Lu, Wei,Du, Ganhong,Liu, Keyuan,Jiang, Liming,Ling, Jun,Shen, Zhiquan
, p. 283 - 292 (2014)
We propose a new strategy to construct chiral molecular switches with highly reversible and sensitive chiroptical responses to variations in the external environment. Its fundamental concept involves a stimuli-triggered exchange of two conformations presenting significantly different chiroptical properties through the rotation of a carbon-carbon single bond, as demonstrated by chiral Schiff bases s-1, s-2, and a salicylamide analogue s-3. Upon addition of base in solution, the circular dichroism (CD) spectra of these molecular switches displayed unique changes featuring an inversion of the Cotton effect's signs, and the original CD profiles can be recoverd by acidification. Various spectroscopic studies as well as the conformational analysis combining with TDDFT computations allowed clear elucidation of the chiroptical inversion mechanism. It is expected that this kind of chiroptical switches is of great interest for molecular recognition, chemosensing, and the construction of molecular-scale devices. Furthermore, the present study indicates that the use of the conformational transition about a single bond may serve as the basis for designing chiroptical inversion systems.
4-Acylhydrazinomethylene-2-phenyloxazol-5(4H)-ones as acylating agents: Synthesis of salicylanilides and 1,2,4-triazolo[4,3-b] pyridazines
Po?gan, Franc,Polanc, Slovenko,Ko?evar, Marijan
, p. 1011 - 1019 (2007/10/03)
A simple and general method for the acylation of an amino or hydrazino group by the application of hydrazides has been developed. It starts from hydrazides (2), which are converted with 4-ethoxymethylene-2-phenyl-oxazol-5(4H)-one (1) to the corresponding 4-acylhydrazinomethylene-2-phenyloxazol-5(4H)-ones (3). The latter react with nitrogen-containing nucleophiles in 1,4-dioxane in the presence of triethylamine or zirconium(IV) chloride to give the corresponding amides (7) or mixtures of hydrazides (12) and 1,2,4-triazolo[4,3-b]pyridazines (11). Upon prolonged heating, compounds (11) are the main products.
STEREOCHEMICAL INVESTIGATIONS. LII. CHIRAL AMIDES OF o-HYDROXY- AND o-METHOXY-SUBSTITUTED BENZOIC ACIDS
Solov'eva, L. D.,Dem'yanovich, V. M.,Potapov, V. M.
, p. 1099 - 1105 (2007/10/02)
A number of o-hydroxy- and o-methoxybenzamides have been obtained from (-)-α-phenylamine, (+)-α-benzylethylamine, and (-)-1,2-diphenylethylamine, and their UV, IR, PMR, and CD spectra have been studied.The chiral optical properties of these amides are determined primarily by the nature of the cyclic structure which can form as a result of intramolecular hydrogen bonding.
