Results 51 to 60 of about 60,159 (283)

A Pyridinium Ylide-alkylation Strategy for the Structural Diversification of N-Carbamoyl Pyridinium Salts [PDF]

open access: yes
A pyridinium-ylide alkylation strategy has been developed for accessing N,N-disubstituted carbamoyl pyridinium salts that possess multiple nucleophilic sites.
Michael, Taylor   +2 more
core   +2 more sources

Bis[2-(2,4-dinitrobenzyl)pyridinium] biphenyl-4,4′-disulfonate trihydrate [PDF]

open access: yes, 2010
In the structure of the title salt, 2C12H10N 3O4 +·C12H8O 6S2 2-·3H2O, determined at 173 K, the biphenyl-4,4′-disulfonate dianions lie across crystallographic inversion centres with the sulfonate groups inter-acting head-to-head through centrosymmetric ...
Young, David J   +9 more
core   +2 more sources

Investigation of the Pyridinium Ylide—Alkyne Cycloaddition as a Fluorogenic Coupling Reaction

open access: yesMolecules, 2016
The cycloaddition of pyridinium ylides with alkynes was investigated under mild conditions. A series of 13 pyridinium salts was prepared by alkylation of 4-substituted pyridines.
Simon Bonte   +4 more
doaj   +1 more source

Sulfur‐Free Ultrahigh‐Refractive‐Index Polymers Enabled by Densely Packed Oxygen‐Bridged Dibenzofuran‐Cardo Architectures

open access: yesAdvanced Functional Materials, EarlyView.
A new class of sulfur‐free, oxygen‐bridged dibenzofuran‐based polymers is developed for ultrahigh‐refractive‐index applications. The rigid π‐extended architecture and enhanced molecular polarizability enable exceptional optical performance, combining refractive indices up to 1.848 with high Abbe numbers and full visible transparency. This work offers a
Hend A. Hegazy   +5 more
wiley   +1 more source

Simplexidine, a 4-Alkylpyridinium Alkaloid from the Caribbean Sponge Plakortis simplex

open access: yesMolecules, 2008
Chemical analysis of the secondary metabolites of the Caribbean sponge Plakortis simplex, a source of many bioactive compounds, showed the presence of the new metabolite simplexidine (4), belonging to the extremely rare class of 4-alkyl-pyridinium ...
Orazio Taglialatela-Scafati   +3 more
doaj   +1 more source

Regioselective Alkylation of Pyridinium Riboses [PDF]

open access: yesEuropean Journal of Organic Chemistry, 2020
The nucleophilic addition of alkyl, benzyl, and allyl organozinc reagents to protected pyridinium riboses proceeds under mild conditions and with yields of > 90 % in several cases and complete regioselectivity for the 4‐position.
Farbod Salahi, Olaf Wiest
openaire   +2 more sources

Highly Electron-Deficient Pyridinium-Nitrones for Rapid and Tunable Inverse-Electron-Demand Strain-Promoted Alkyne-Nitrone Cycloaddition to Bicyclo[6.1.0]nonyne [PDF]

open access: yes, 2019
Highly accelerated inverse-electron-demand strain-promoted alkyne-nitrone cycloaddition (IED SPANC) between a sta- ble cyclooctyne (bicyclo[6.1.0]nonyne (BCN)) and nitrones delocalized into a Cα-pyridinium functionality is reported, with the ...
Alexander M., Polgar   +4 more
core   +1 more source

Extrusion Bioprinting for Wound Healing: Innovations in Functionalized Bioinks and Bioprinting Technology

open access: yesAdvanced Materials Technologies, EarlyView.
Extrusion‐based bioprinting (EBB) has emerged as a versatile biofabrication platform capable of precisely depositing bioinks composed of biomaterials, cells, and bioactive agents to generate patient‐specific, biomimetic skin constructs. This paper presents a state‐of‐the‐art and forward‐looking overview of EBB for wound healing, encompassing printing ...
Hien‐Phuong Le   +4 more
wiley   +1 more source

Crystal structure of 2-cyano-1-methylpyridinium perchlorate

open access: yesActa Crystallographica Section E: Crystallographic Communications, 2015
The asymmetric unit of the title salt, C7H7N2+·ClO4−, comprises two independent formula units. The solid-state structure comprises corrugated layers of cations and of anions, approximately parallel to (010).
Vu D. Nguyen   +3 more
doaj   +1 more source

2-(Benzenesulfonamido)pyridinium perchlorate [PDF]

open access: yesActa Crystallographica Section E Structure Reports Online, 2009
In the title compound, C11H11N2O2S+·ClO4−, the dihedral angle between the benzene and pyridinium rings is 87.33 (10)°. An intramolecular N—H...O interaction, with an S=O-bonded O atom as receptor, occurs in the cation. In the crystal structure, ion pairs occur, being linked by strong N—H...O hydrogen bonds. The perchlorate anion plays a further role in
Xun Li   +3 more
openaire   +3 more sources

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