Platinum(II) Diphosphinamine Complexes for the Efficient Hydration of Alkynes in Micellar Media
作者:Francesco Trentin、Andrew M. Chapman、Alessandro Scarso、Paolo Sgarbossa、Rino A. Michelin、Giorgio Strukul、Duncan F. Wass
DOI:10.1002/adsc.201100326
日期:2012.4.16
Highly active monomeric bis‐cationic platinum(II) catalysts bearing small bite angle diphosphinamine [N,N‐bis(diarylphosphino)amine] ‘PNP’ ligands efficiently catalyze Markovnikov hydration of terminal and internal alkynes to the corresponding ketones in water. Catalyst solubilization in water is achieved via ion pairing with anionic micelles formed by surfactant addition. The micelles ensure dissolution
Ring-transformations of pyrimidines by intramolecular diels-alder reactions. Synthesis of annelated fyridines
作者:A.E. Frissen、A.T.M. Marcelis、H.C. Van Der Plas
DOI:10.1016/0040-4020(89)80111-5
日期:1989.1
Pyrimidines carrying an ω-alkyne side-chain -XCH2CH2CCH (X=O,N,S,SO,SO2) at the 2 or 5 position undergo intramolecularinverseelectrondemandDiels-Alderreactions across the C-2 and C-5 positions; elimination of hydrogen (or alkyl) cyanide from the intermediate adducts leads to condensed pyridines. The influence of the hetero atom (X) in the dienophilic side-chain and that of substituents in the
Liquid–Liquid Extraction Protocol for the Removal of Aldehydes and Highly Reactive Ketones from Mixtures
作者:Maria M. Boucher、Maxwell H. Furigay、Phong K. Quach、Cheyenne S. Brindle
DOI:10.1021/acs.oprd.7b00231
日期:2017.9.15
The reaction of the bisulfite ion with aldehydes to form charged bisulfite adducts is a well-established method for the purification of aldehydes. This reaction has been modified to create a convenient liquid–liquid extraction method for the removal of aldehydes from mixtures. The use of a water-miscible solvent allows the reaction to occur during a simple 30 s shaking protocol by increasing the contact
Migratory Hydrogenation of Terminal Alkynes by Base/Cobalt Relay Catalysis
作者:Xufang Liu、Bingxue Liu、Qiang Liu
DOI:10.1002/anie.201916014
日期:2020.4.20
an analogous protocol for alkyne substrates is yet to be developed. Herein, a base and cobalt relay catalytic process for the selective synthesis of (Z)-2-alkenes and conjugated E alkenes by migratory hydrogenation of terminalalkynes is disclosed. Mechanistic studies support a relay catalytic process involving a sequential base-catalyzed isomerization of terminalalkynes and cobalt-catalyzed hydrogenation
Piperidine compounds and their preparation and use
申请人:Novo Nordisk A/S
公开号:US05041455A1
公开(公告)日:1991-08-20
The present invention relates to therapeutically active piperidine compounds, a method of preparing the same and to pharmaceutical compositions comprising the compounds. The novel compounds are useful as stimulants of the cognitive function of the forebrain and hippocampus of mammals and especially in the treatment of Alzheimer's disease, severe painful conditions and glaucoma.