Results 21 to 30 of about 231,579 (192)

Synthesis of 1,4-Disubstituted Mono and Bis-triazolocarbo-acyclonucleoside Analogues of 9-(4-Hydroxybutyl)guanine by Cu(I)-Catalyzed Click Azide-Alkyne Cycloaddition [PDF]

open access: yes, 2011
A series of novel mono-1,2,3-triazole and bis-1,2,3-triazole acyclonucleoside analogues of 9-(4-hydroxybutyl)guanine was prepared via copper(I)-catalyzed 1,3-dipolar cycloaddition of N-9 propargylpurine, N-1-propargylpyrimidines/as-triazine with the ...
Krim, Jamal   +5 more
core   +1 more source

Phospha-Münchnones: Electronic Structures and 1,3-Dipolar Cycloadditions

open access: yes, 2016
The reaction of imines, acid chlorides, PR3, and base generates a new class of 1,3-dipoles: phospha-Münchnones. These 1,3-dipoles can undergo cycloadditions with alkynes followed by loss of phosphine oxides to form pyrroles.
Bruce A. Arndtsen (1310721)   +5 more
core   +4 more sources

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

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

Site-Selective Modification of a Porpholactone—Selective Synthesis of 12,13- and 17,18-Dihydroporpholactones

open access: yesMolecules, 2020
The reaction of meso-tetrakis(pentafluorophenyl)porpholactone with azomethine ylides and nitrones affords pyrrolidine-fused and isoxazolidine-fused dihydroporpholactones that display, respectively, isobacteriochlorin- and chlorin-type UV–Vis spectra ...
Ana F. R. Cerqueira   +5 more
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

MnVI-NP–Catalyzed Generation of Nitrile Oxides: Easy Access to Isoxazolines and Isoxazoles via Stereoselective 1,3-Dipolar Cyclo­addition Reactions

open access: yesSynOpen, 2022
The versatility and effectiveness of MnVI-NPs as a catalyst is examined for the generation of nitrile oxides from aldoximes and subsequent 1,3-dipolar cycloaddition reactions.
Yasmin Saima, Saikat Khamarui
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

1,3-Dipolar Cycloadditions of Chiral Nitrones [PDF]

open access: yes, 1989
The asymmetric synthesis of natural products via 1,3-dipolar cycloadditions of chiral nitrones to prochiral olefins has been an area of intense activity over the past decade. The work described in this thesis involves the application of two short, highly
Keirs, David
core   +6 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

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