Results 21 to 30 of about 264,075 (214)

On the strong difference in reactivity of acyclic and cyclic diazodiketones with thioketones: experimental results and quantum-chemical interpretation

open access: yesBeilstein Journal of Organic Chemistry, 2015
The 1,3-dipolar cycloaddition of acyclic 2-diazo-1,3-dicarbonyl compounds (DDC) and thioketones preferably occurs with Z,E-conformers and leads to the formation of transient thiocarbonyl ylides in two stages.
Andrey S. Mereshchenko   +5 more
doaj   +1 more source

Nitropyridines as 2π-Partners in 1,3-Dipolar Cycloadditions with N-Methyl Azomethine Ylide: An Easy Access to Condensed Pyrrolines

open access: yesMolecules, 2021
1,3-Dipolar cycloaddition reactions of 2-substituted 5-R-3-nitropyridines and isomeric 3-R-5-nitropyridines with N-methyl azomethine ylide were studied. The effect of the substituent at positions 2 and 5 of the pyridine ring on the possibility of the [3 ...
Maxim A. Bastrakov   +3 more
doaj   +1 more source

A de‐novo Approach Towards Divergent [3+2π/σ] Photocycloadditions of Nitrones via Assembly‐Controlled Kinetic Electron Transfer Gating

open access: yesAngewandte Chemie, EarlyView.
A metal‐free photocatalytic platform converts nitrones into 4‐isoxazolines and oxa–aza–bicycloheptanes through divergent [3+2π/σ] cycloadditions. Assembly‐controlled kinetic electron transfer gating dictates substrate activation, enabling selective reactivity beyond thermodynamic expectations.
Nayan Saha   +6 more
wiley   +2 more sources

Kinetic Resolution of Alkylidene Norcamphors via a Ligand-Controlled Umpolung-Type 1,3-Dipolar Cycloaddition

open access: yesiScience, 2019
Summary: Development of a general catalytic and highly efficient method utilizing readily available precursors for the regio- and stereoselective construction of bioactive natural-product-inspired spiro architectures remains a formidable challenge in ...
Chong Shen   +5 more
doaj   +1 more source

Farnesyltransferase Enables Modular Assembly of Dual‐Functional Nanobody Conjugates for in Vivo Imaging of Inflammation

open access: yesAngewandte Chemie, EarlyView.
A modular farnesyltransferase‐based chemoenzymatic platform enables fast, site‐specific labeling of nanobodies for PET imaging of inflammation. CD11b‐targeted PET agents selectively image myeloid‐driven inflammation, while CD45‐targeted PET agents provide sensitive whole‐body immune mapping.
Sneha Venkatachalapathy   +7 more
wiley   +2 more sources

N-Alkylated dinitrones from isosorbide as cross-linkers for unsaturated bio-based polyesters

open access: yesBeilstein Journal of Organic Chemistry, 2014
Isosorbide was esterified with acryloyl chloride and crotonic acid yielding isosorbide diacrylate (9a) and isosorbide dicrotonate (9b), which were reacted with benzaldehyde oxime in the presence of zinc(II) iodide and boron triflouride etherate as ...
Oliver Goerz, Helmut Ritter
doaj   +1 more source

TADF‐Active Tetrazole Luminophores for Visible‐Light Functionalization of Nanoparticles and Surfaces

open access: yesAngewandte Chemie, EarlyView.
A series of tetrazoles are reported that undergo 1,3‐dipolar cycloadditions with alkene and alkyne substrates, generating (dihydro)pyrazole products that exhibit thermally activated delayed fluorescence (TADF). The “photo‐click” reactivity of these tetrazoles is leveraged to functionalize nanoparticles and surfaces with TADF‐active chromophores ...
Ryoga Hojo   +11 more
wiley   +2 more sources

Synthesis of Different Heterocyclic Compounds of Pharmaceutical Relevance [PDF]

open access: yes
This thesis describes the synthesis of different cyclic imines and the exploration of their reactivity with cyclopropenones and 1,3-dipoles,as well as an investigation of the chemistry of the products.
Khan, Musharraf Naveed
core   +3 more sources

Synthesis and reinvestigation of tetrazocines [PDF]

open access: yes, 2004
This thesis is concerned with the study of tetrazocines. These rare, eight-membered ring systems containing four nitrogen atoms are in the infancy of their development. Little is known of their potential application, properties and generation.
Healy, Cathal
core   +2 more sources

A Suitable Functionalization of Nitroindazoles with Triazolyl and Pyrazolyl Moieties via Cycloaddition Reactions

open access: yesMolecules, 2019
The alkylation of a series of nitroindazole derivatives with 1,2-dibromoethane afforded the corresponding N-(2-bromoethyl)- and N-vinyl-nitro-1H-indazoles.
Mohammed Eddahmi   +9 more
doaj   +1 more source

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