13794-14-4Relevant articles and documents
Access to Optically Enriched α-Aryloxycarboxylic Esters via Carbene-Catalyzed Dynamic Kinetic Resolution and Transesterification
Liu, Bin,Song, Runjiang,Xu, Jun,Majhi, Pankaj Kumar,Yang, Xing,Yang, Song,Jin, Zhichao,Chi, Yonggui Robin
supporting information, p. 3335 - 3338 (2020/04/30)
Optically active α-aryloxycarboxylic acids and their derivatives are important functional molecules. Disclosed here is a carbene-catalyzed dynamic kinetic resolution and transesterification reaction for access to this class of molecules with up to 99% yields and 99:1 er values. Addition of a chiral carbene catalyst to the ester substrate leads to two diastereomeric azolium ester intermediates that can quickly epimerize to each other and thus allows for effective dynamic kinetic resolution to be realized. The optically enriched ester products from our reaction can be quickly transformed to chiral herbicides and other bioactive molecules.
Presynaptic cholinergic modulators as potent cognition enhancers and analgesic drugs. 2. 2-Phenoxy-, 2-(phenylthio)-, and 2-(phenylamino)alkanoic acid esters
Gualtieri,Bottalico,Calandrella,Dei,Giovannoni,Mealli,Romanelli,Scapecchi,Teodori,Galeotti,Ghelardini,Giotti,Bartolini
, p. 1712 - 1719 (2007/10/02)
Further modifications of the leads ((R)-(+)-hyoscyamine and (p- chlorophenyl)propionic acid α-tropanyl ester), which show analgesic and nootropic activities as a consequence of increased central presynaptic ACh release, are reported. 2-Phenoxy- and 2-(phenylthio)alkanoic acid esters showed the best results. Several members of these classes possess analgesic properties which are comparable to that of morphine and at the same time are able to reverse dicyclomine-induced amnesia. Confirmation was found that the mechanism of action is due to an increase in ACh release at central muscarinic synapses and that both auto- and heteroreceptors controlling ACh release are very likely involved. According to the results obtained with (R)- (+)-hyoscyamine, analgesic activity is stereochemistry dependent, since the R-(+)-enantiomers are always more efficacious than the corresponding S-(-)- ones. On the basis of their potency and acute toxicity, compounds (±)-28 (SM21) and (±)-42 (SM32) were selected for further study.
