Results 21 to 30 of about 57,923 (191)

Intramolecular Cycloaddition of Imines of Cysteine Derivatives

open access: yesMolecules, 1998
Azomethine ylides were generated from Schiffs bases of S-allylcysteine methyl ester and their intramolecular 1,3-dipolar cycloadditions were studied. These reactions led to the synthesis of thieno[3,4-b]pyrrole derivatives in good yield.
Teresa M. V. D. Pinho e Melo   +2 more
doaj   +1 more source

1,3-Dipolar Cycloaddition Reactions of Azomethine Ylides with Carbonyl Dipolarophiles Yielding Oxazolidine Derivatives

open access: yesMolecules, 2016
We provide a comprehensive account of the 1,3-dipolar cycloaddition reactions of azomethine ylides with carbonyl dipolarophiles. Many different azomethine ylides have been studied, including stabilized and non-stabilized ylides.
Adam G. Meyer, John H. Ryan
doaj   +1 more source

A study on selective transformation of norbornadiene into fluorinated cyclopentane-fused isoxazolines

open access: yesBeilstein Journal of Organic Chemistry, 2021
This work presents an examination of the selective functionalization of norbornadiene through nitrile oxide 1,3-dipolar cycloaddition/ring-opening metathesis (ROM)/cross-metathesis (CM) protocols. Functionalization of commercially available norbornadiene
Zsanett Benke   +2 more
doaj   +1 more source

Arylthio-substituierte Nitrilylide aus der Thermolyse von 4-Arylthio-3-oxazolin-5-onen

open access: yesCHIMIA, 1984
Thermolysis of 4-arylthio- and 4-benzylthio-3-oxazolin-5-ones leads to arylthio- and benzylthio-substituted nitrile ylides, which undergo 1,3-dipolar cycloadditions with reactive dipolarophiles to give 5-membered aza-heterocycles (Schemes 1 and 2).
Peter Wipf, Heinz Heimgartner
doaj   +1 more source

Reaction profiles for quantum chemistry-computed [3 + 2] cycloaddition reactions

open access: yesScientific Data, 2023
Bio-orthogonal click chemistry based on [3 + 2] dipolar cycloadditions has had a profound impact on the field of biochemistry and significant effort has been devoted to identify promising new candidate reactions for this purpose.
Thijs Stuyver   +2 more
doaj   +1 more source

1,3-Dipolar Cycloadditions to Bicyclic Olefins. I. 1,3-Dipolar Cycloadditions to Norbornadienes [PDF]

open access: yesBulletin of the Chemical Society of Japan, 1977
Abstract The 1,3-dipolar cycloadditions of phenylglyoxylonitrile oxide, benzonitrile-N-phenylimine, or N-phenyl-C-p-nitrophenylnitrone to norbornadiene, 2,3-dicyanonorbornadiene, and 2,3-bis(methoxycarbonyl)norbornadiene give the endo-adducts, together with the exo-adducts.
Hisaji Taniguchi   +3 more
openaire   +1 more source

Highly Enantio‐ and Diastereoselective Synthesis of Tetrahydrofuran Frameworks via Chiral Lewis Acid‐Catalyzed Formal [3+2] Cycloaddition of Allylsilanes

open access: yesAngewandte Chemie, EarlyView.
The first catalytic asymmetric formal [3+2] cycloaddition of allylsilanes delivers cis‐2,5‐disubstituted tetrahydrofuran‐3‐ones that serve as versatile intermediates for the synthesis of diverse bioactive scaffolds. ABSTRACT A formal [3+2] cycloaddition via cyclization/1,2‐hydride shift initiated by nucleophilic attack of allylsilanes has been ...
Hosung Lee   +5 more
wiley   +2 more sources

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

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

Copper nanoparticles on controlled pore glass (CPG) as highly efficient heterogeneous catalysts for “click reactions”

open access: yesScientific Reports, 2020
We herein report that supported copper nanoparticles (CuNPs) on commercially available controlled pore glass (CPG), which exhibit high mechanical, thermal and chemical stability as compared to other silica-based materials, serve as a useful heterogeneous
Abdolrahim A. Rafi   +2 more
doaj   +1 more source

Home - About - Disclaimer - Privacy