Results 31 to 40 of about 23,632 (231)

Asymmetric Hydrogenation of 3‐Substituted Pyridinium Salts

Chemistry – A European Journal, 2016
AbstractThe use of an equivalent amount of an organic base leads to high enantiomeric excess in the asymmetric hydrogenation of N‐benzylated 3‐substituted pyridinium salts into the corresponding piperidines. Indeed, in the presence of Et3N, a Rh‐JosiPhos catalyst reduced a range of pyridinium salts with ee values up to 90 %.
M. Renom-Carrasco, GAJEWSKI, PIOTR, PIGNATARO, LUCA LUIGI, J. De Vries, U. Piarulli, C. Gennari, L. Lefort   +6 more
openaire   +4 more sources

Hydroxyl Functionalized Pyridinium Ionic Liquids: Experimental and Theoretical Study on Physicochemical and Electrochemical Properties

Frontiers in Chemistry, 2019
Structurally modified hydroxyl functionalized pyridinium ionic liquids (ILs), liquid at room temperature, were synthesized and characterized. Alkylated N-(2-hydroxyethyl)-pyridinium ILs were prepared from alkylpyridines via corresponding bromide salts by
Kallidanthiyil Chellappan Lethesh, Sigvart Evjen, Jaganathan Joshua Raj, Denis C. D. Roux, Vishwesh Venkatraman, Kaushik Jayasayee, Anne Fiksdahl   +6 more
doaj   +1 more source

Visible light induced alkene aminopyridylation using N-aminopyridinium salts as bifunctional reagents

Nature Communications, 2019
A key difficulty to overcome in pyridinium salts functionalization is the regioselectivity at the two competing C2 and C4 sites. Here, the authors show bifunctional N-aminopyridinium salts reagents delivering both the aminyl radical and the pyridyl group
Yonghoon Moon, Bohyun Park, Inwon Kim, Gyumin Kang, Sanghoon Shin, Dahye Kang, Mu-Hyun Baik, Sungwoo Hong   +7 more
doaj   +1 more source

Synthesis of 6-Nitroderivatives of Oxazolo[3,2-a]-pyridines and Their Reactions with Nucleophiles

Molecules, 2003
5-Nitro-2-pyridone can be selectively N-phenacylated, and the resulting phenacylpyridones I undergo cyclization to 6-nitrooxazolo[3,2-a]pyridinium salts II.
Eugene V. Babaev, Alexander A. Bush
doaj   +1 more source

Synthesis of Pyridinium Amphiphiles Used for Transfection and Some Characteristics of Amphiphile/DNA Complex Formation [PDF]

, 2000
Pyridinium amphiphiles have found practical use for the delivery of DNA into cells. Starting from 4-methylpyridine, a general synthesis has been devised for the production of pyridinium amphiphiles which allows variation in both the hydrophobic part and ...
Bosgraaf, Bouke,, Brisson, Alain,, Engberts, Jan B.F.N.,, Haadsma, Peter,, Hoekstra, Dick,, Kroeze, Jessica E.,, Meekel, Arthur A.P.,, Ruiters, Marcel H.J.,, Stuart, Marc C.A.,, Wagenaar, Anno,, Šmisterová, Jarmila,   +10 more
core   +2 more sources

From optically pure pyridinium salts to some new dihydro-2H-oxazolo[3,2-a]pyridines

Results in Chemistry, 2023
Treatment of 2,4,6-triphenylpiridinium salts, bearing a chiral β-hydroxy alkyl N-substituent with diluted aqueous sodium hydroxide afforded four new dihydrooxazolo[3,2a]pyridines,as an almost equimolar mixture of diastereomers.
R.G. Moura, P.R. Batista, L.C. Ducati, J. Gruber, L.F. Yamaguchi, L. Marzorati   +5 more
doaj   +1 more source

Syntheses and Properties of Two-Dimensional, Dicationic Nonlinear Optical Chromophores Based on Pyrazinyl Cores [PDF]

, 2010
Six new dicationic 2D nonlinear optical (NLO) chromophores with pyrazinyl-pyridinium electron acceptors have been synthesized by nucleophilic substitutions of 2,6-dichloropyrazine with pyridyl derivatives. These compounds have been characterized as their
Asselberghs, Inge, Brunschwig, Bruce S., Clays, Koen, Coe, Benjamin J., De Mey, Kurt, Fielden, John, Foxon, Simon P., Helliwell, Madeleine   +7 more
core   +2 more sources

Synthesis and Characterization of Novel Pyridinium Salts of (E)-2-(Pyridin-4-ylmethylene)hydrazine-1-carboximidamide

Molbank
We report the synthesis and characterization of the novel pyridinium salts from (E)-2-(pyridin-4-ylmethylene)hydrazine-1-carboximidamide. The pyridinium salts were obtained via the reaction of guanylhydrazone derived from pyridine-4-carbaldehyde with ...
Fatemeh Ataie Alani, Fatemeh Ahmadian, Alireza Houshdar Tehrani, Salimeh Amidi   +3 more
doaj   +1 more source

Reaction of Picolinamides with Ketones Producing a New Type of Heterocyclic Salts with an Imidazolidin-4-One Ring

Molecules, 2023
Reactions of picolinamides with 1,3-propanesultone in methanol followed by the treatment with ketones led to a series of previously unknown chemical transformations, yielding first pyridinium salts (2a–f), with a protonated endocyclic nitrogen atom, and ...
Eugenia P. Kramarova, Dmitry N. Lyakhmun, Dmitry V. Tarasenko, Sophia S. Borisevich, Edward M. Khamitov, Alfia R. Yusupova, Alexander A. Korlyukov, Alexander R. Romanenko, Tatiana A. Shmigol, Sergey Yu. Bylikin, Yuri I. Baukov, Vadim V. Negrebetsky   +11 more
doaj   +1 more source

Electronic Tuning of Mixed Quinoidal‐Aromatic Conjugated Polyelectrolytes: Direct Ionic Substitution on Polymer Main‐Chains [PDF]

, 2019
The synthesis of conjugated polymers with ionic substituents directly bound to their main chain repeat units is a strategy for generating strongly electron-accepting conjugated polyelectrolytes, as demonstrated through the synthesis of a series of ionic ...
Anderson, Christopher L, Dai, Nan, He, Bo, Liu, Yi, Teat, Simon J, Wang, Shu   +5 more
core   +3 more sources