Results 21 to 30 of about 2,217 (174)

Halogen-Bond Mediated [2+2] Photodimerizations: À la Carte Access to Unsymmetrical Cyclobutanes in the Solid State

open access: yesMolecules, 2022
The ditopic halogen-bond (X-bond) donors 1,2-, 1,3-, and 1,4-diiodotetrafluorobenzene (1,2-, 1,3-, and 1,4-di-I-tFb, respectively) form binary cocrystals with the unsymmetrical ditopic X-bond acceptor trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene (2,4-bpe ...
Jay Quentin   +2 more
doaj   +1 more source

Strain‐Release Pentafluorosulfanylation of Carbonyl‐Containing Disubstituted Bicyclobutanes: A Fortuitous Path to SF5‐Containing Oxa[2.1.1]bicyclohexanes

open access: yesAngewandte Chemie, EarlyView.
A regio‐ and diastereoselective method for strain‐release pentafluorosulfanylation of carbonyl‐containing 1,3‐disubstituted [1.1.0]bicyclobutanes (BCBs) was developed that led to several fortuitous discoveries. For instance, the resultant SF5‐cyclobutanes (SF5‐CBs) exhibit close SF5⋯C═X contacts (X = C, N, O) and provide synthetic access to a new class
Alexander M. Stephens   +9 more
wiley   +2 more sources

Borylcyclopropanes: Synthetic Strategies and Applications

open access: yesAngewandte Chemie, EarlyView.
Borylcyclopropanes (cyclopropanes bearing a boron substituent) sit at the intersection of two privileged frameworks in synthesis. This review provides the first exhaustive survey of their chemistry, spanning metal–carbene, nucleophilic cyclization, radical, hydroboration, and C─H activation routes, and documenting applications in medicinal chemistry ...
Aiza A. Butt, Joseph M. Ready
wiley   +2 more sources

Ring Tension, Hydrocarbon Acidity, and New «Super-Bases»

open access: yesCHIMIA, 1986
Addition of disodium pinacolate or, particularly, potassium tert-butoxide considerably increases the transmetalating power of pentylsodium. A hexane slurry of such «NACNAOR» or «NACKOR» reagent mixtures readily and selectively converts 3,3-dimenthyl-1 ...
Manfred Schlosser   +5 more
doaj   +1 more source

r-1,t-3-Bis[4-(dimethylamino)phenyl]-c-2,t-4-bis(pyridin-4-yl)cyclobutane

open access: yesActa Crystallographica Section E, 2014
The title compound, C30H32N4, was synthesized by the photodimerization of trans-4-{2-[4-(dimethylamino)phenyl]ethenyl}pyridine in benzene upon irradiation with UV light.
Shuguang Zhang, Junpeng Zhuang
doaj   +1 more source

Anethole Isomerization and Dimerization Induced by Acid Sites or UV Irradiation

open access: yesMolecules, 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   +2 more
doaj   +1 more source

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

open access: yesBeilstein 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   +4 more
doaj   +1 more source

White Light Emission and Energy Transfer in Mixed‐Metal Europium/Terbium/Thulium Formate Metal–Organic Frameworks: Effect of Lanthanum Dilution

open access: yesAdvanced Optical Materials, EarlyView.
A series of Eu3+, Tb3+, Tm3+ and La3+ formate‐based (mixed)metal‐organic frameworks were synthesized and investigated for energy transfer and white‐light emission. Efficient Tb3+→Eu3+ transfer enabled tuneable luminescence, while Tm3+ incorporation afforded near‐white emission.
Leonardo E. Cruz‐Estrada   +5 more
wiley   +1 more source

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

open access: yesNatural 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   +3 more
doaj   +1 more source

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

open access: yesMolecules
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   +3 more
doaj   +1 more source

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