6333-08-0Relevant articles and documents
Pyrazoles and pyrazolines as anti-inflammatory agents
Hadjipavlou-Litina, Dimitra,Mantzanidou, Martha,Pontiki, Eleni
, (2021/06/21)
The five-membered heterocyclic group of pyrazoles/pyrazolines plays important role in drug discovery. Pyrazoles and pyrazolines present a wide range of biological activities. The synthesis of the pyrazolines and pyrazole derivatives was accomplished via t
Basic Anion-Exchange Resin-Catalyzed Aldol Condensation of Aromatic Ketones with Aldehydes in Continuous Flow
Laroche, Benjamin,Saito, Yuki,Ishitani, Haruro,Kobayashi, Shū
supporting information, p. 961 - 967 (2019/05/02)
A general method for the aldol condensation of aromatic ketones with aldehydes was developed under continuous-flow conditions using a commercially available, strongly basic anion-exchange resin (A26) as catalyst. This procedure, in addition to exhibiting a wide substrate scope, promoted carbon-carbon bond formation under mild conditions using a quasi-stoichiometric ratio of starting reagents with good to excellent yields, thereby forming a limited amount of waste and allowing the process to be applied to sequential-flow systems. A proof of concept was developed in the first fully heterogeneously catalyzed two-step flow synthesis of donepezil, which is a blockbuster commercial anti-Alzheimer's drug.
Enantioselective Diels-Alder Reactions of Cyclohexa-1,3-diene and Chalcones Catalyzed by Intramolecular Silicon-Sulfur Lewis Pairs as Chiral Lewis Acids
Shaykhutdinova, Polina,Oestreich, Martin
supporting information, p. 2768 - 2771 (2016/09/04)
The stereoselective preparation of diastereomeric dihydrosilepine-derived silicon cations decorated with another binaphthyl unit at the silicon atom is described. A sulfide donor attached to that additional binaphthyl substituent forms an intramolecular Lewis pair with the electron-deficient silicon atom, as verified by 29Si NMR spectroscopy. Both chiral sulfur-stabilized silicon cations act as catalysts in the difficult Diels-Alder reaction of cyclohexa-1,3-diene and chalcone derivatives. Both Lewis acids induce enantioselectivity, but the S,S relative configuration is superior to the S,R configuration. With the former diastereomer, enantiomeric excesses of close to 60% are obtained. These values are the highest achieved to date in this seemingly trivial cycloaddition.