Results 31 to 40 of about 1,032 (168)

The Formal [4+3] Cycloaddition between Donor−Acceptor Cyclobutanes and Nitrones

, 2016
The formal [4+3] cycloaddition of 2-alkoxy-1,1-dicarboxylate activated donor−acceptor cyclobutanes with nitrones is disclosed. The reaction forms structurally unique oxazepines in moderate to high yield with a wide scope of nitrones. In most cases either
Brian L. Pagenkopf (2222299), Andrew C. Stevens (2222302), Cory Palmer (2222296)   +2 more
core   +5 more sources

Elimination versus Ring Opening: A Convergent Route to Alkylidene-Cyclobutanes

, 2016
Functionalized alkylidene-cyclobutanes have been prepared from 2-fluoropyridinyl-6-oxy precursors derived from vinyl cyclobutanols by a radical addition–elimination process.
Béatrice Quiclet-Sire (1672969), Michal Michalak (1448047), Julien Brioche (1359096), Samir Z. Zard (1490782)   +3 more
core   +1 more source

[2+2]-Photocycloadditions of 1,4-Naphthoquinone Under Batch and Continuous-Flow Conditions

Molecules
A series of [2+2]-photocycloadditions of 1,4-naphthoquinone with various alkenes and diphenylacetylene were investigated under batch and continuous-flow conditions.
Madyan A. Yaseen, Zhifang Guo, Peter C. Junk, Michael Oelgemöller   +3 more
doaj   +1 more source

Anethole Isomerization and Dimerization Induced by Acid Sites or UV Irradiation

Molecules, 2010
The formation of cis-anethole and various dimers as a result of the exposure of trans-anethole to microporous solid acids (dealuminated HY zeolites), or UV-Vis irradiation was established by means of high resolution gas chromatography coupled to mass ...
Elena Stashenko, Jairo René Martínez, Hans T. Castro   +2 more
doaj   +1 more source

Photo‐Degradable Polyester Networks and Multi‐Photon Printed Objects Based on Cyclic Ketene Acetals

Advanced Functional Materials, EarlyView.
The current work introduces a photoreversible polyester network derived from radical ring‐opening polymerization of cyclic ketene acetals. It combines photoreversible cross‐linking with initiator‐free multi‐photon printing. Reversible network formation, tunable mechanical properties, and selective degradation highlight its potential as a versatile ...
Till Meissner, Julian Fanelli, Vinh Xuan Truong, Rob Jones, Jens Gaitzsch, Christopher Barner‐Kowollik   +5 more
wiley   +1 more source

Recent advances in the application of [2 + 2] cycloaddition in the chemical synthesis of cyclobutane-containing natural products

Natural Products and Bioprospecting
Cyclobutanes are distributed widely in a large class of natural products featuring diverse pharmaceutical activities and intricate structural frameworks.
Song-Yu Hou, Bing-Chao Yan, Han-Dong Sun, Pema-Tenzin Puno   +3 more
doaj   +1 more source

Reversible photoswitching of the DNA-binding properties of styrylquinolizinium derivatives through photochromic [2 + 2] cycloaddition and cycloreversion

Beilstein Journal of Organic Chemistry, 2020
It was demonstrated that styrylquinolizinium derivatives may be applied as photoswitchable DNA ligands. At lower ligand:DNA ratios (≤1.5), these compounds bind to duplex DNA by intercalation, with binding constants ranging from Kb = 4.1 × 104 M to 2.6 ...
Sarah Kölsch, Heiko Ihmels, Jochen Mattay, Norbert Sewald, Brian O. Patrick   +4 more
doaj   +1 more source

Cyclization and annulation reactions of nitrogen-substituted cyclopropanes and cyclobutanes [PDF]

Cyclization and annulation reactions initiated by ring-opening of small rings, especially cyclopropanes and cyclobutanes are now well-established in synthetic chemistry.
De Nanteuil, F., De Simone, F., Benfatti, F., Waser, J., Serrano, E., Frei, R.   +5 more
core   +2 more sources

Diastereoselective synthesis of multi-substituted cyclobutanes via catalyst-controlled regiodivergent hydrophosphination of acyl bicyclobutanes

Nature Communications
Although ring-opening reactions of bicyclo[1.1.0]butanes (BCBs) provide a reliable platform for synthesizing functionalized cyclobutanes, current methods frequently encounter challenges such as poor diastereoselectivity, regioselectivity issues, and a ...
Heng-Xian He, Feng Wu, Kun-Ju Wang, Lei Wang, Jian-Jun Feng   +4 more
doaj   +1 more source

Silylium-Catalyzed Activation of Donor- Acceptor Strained Rings and Annulation with Indoles

CHIMIA
Leveraging the unique reactivity profile of donor-acceptor aminocyclopropanes and cyclobutanes allows the preparation of complex nitrogen-substituted molecules. While most reports focus on donor-acceptor strained rings with two geminal carbonyl groups as
Emma G. L. Robert, Jérôme Waser
doaj   +1 more source