Benzylidene Ketones Research Articles

Effect of substituents on the performance of N-carbazolyl double benzylidene ketones in visible/NIR light one/two-photon polymerization

Developing high-performance photoinitiation systems with high sensitivity is of great significance in one/two-photon polymerization. Especially, photoinitiators with rapid photobleaching effects, deep curing abilities and potential for two-photon lithography have great commercial prospects. However, such photoinitiators often require complex organic synthesis, thus having relatively limited varieties. Double benzylidene ketone is widely used as a high-performance dye and can be constructed through a one-step classical aldol condensation reaction. The optimization of its structure often involves introducing extended conjugated structures or different terminal substituents. However, the synergistic impacts of side substituents with different electron effects are rarely studied. Here, six novel carbazolyl double benzylidene ketones with tert-butyl on the terminal position and F atom or N, N-dimethylamino groups substituted at the side position on conjugated structures are designed and prepared to explore the structure–activity relationships. Notably, results show that introducing electron-donating groups at both positions can effectively induce a redshift in the absorption spectra of molecules, and the introduction of an electron-withdrawing F atom on the side position induces impressive photobleaching during photopolymerization under visible LED irradiation. Moreover, CZs/MDEA with PETA exhibit fast writing speed and excellent nano-patterning capability under 780 nm laser in two-photon polymerization (TPP) and have potential applications in 3D microfabrication technologies.

Triphenylamine based benzylidene ketones as visible-light-absorbing Type II photoinitiators for free radical photopolymerization

In this study, four Type II visible-light-absorbing triphenylamine benzylidene ketones (C1F–C4F) for radical photopolymerization were synthesized. The design strategy for ketone-cores involved the use of cyclobutanone for C1F, cyclopentanone for C2F, cyclohexanone for C3F, and acetone for C4F. The structures were confirmed by 1H NMR, 13C NMR, and mass spectrometry, respectively. The triphenylamine benzylidene ketones had good light harvesting ranging from 350 to 500 nm. In addition, the core effects with alkane or alicyclic rings on the photophysical, thermal, photochemical and electrochemical properties for these compounds were investigated systematically. Finally, the photopolymerization experiments demonstrated that trimethylolpropane triacrylate (TMPTA) monomer can be initiated for photopolymerization by triphenylamine benzylidene ketones (C1F–C4F)/triethanolamine (TEOA) photoinitiating systems under UV, LED@405 nm and LED@468 nm exposures. Particularly, C4F based formulation exhibits the best double bond conversion efficiency under UV and LED@468 nm exposure. On the other hand, C1F based formulation exhibits higher photoreactivity under LED@405 nm irradiation condition. This work thus demonstrates the introduction of different cores into the benzylidene, which can fine-tune the photopolymerization characteristics and let these novel photoinitiators promising candidates for industrial applications.

Double benzylidene ketones as photoinitiators for visible light photopolymerization

In this work, four novel double benzylidene ketone dyes (TPA-H, CZ-H, TPA-C, and CZ-C) with D–A structure were synthesized and showed good charge transfer characteristics and high absorption capability in the visible light range. The double benzylidene ketone dyes can be used as type II photoinitiators to initiate free radical photopolymerization (FRP) or as charge transfer sensitizers to sensitize diaryliodonium salt (ONI) synergistically for the initiation of FRP and cationic photopolymerization (CP) together with aromatic amine groups under 460 and 532 nm LED light sources. FRP and CP experiments revealed that TPA-C and CZ-C with polyarylamine groups had high sensitization and initiation activities under 460 and 532 nm LED light sources. The photochemical properties of the initiator system were investigated by means of steady-state photolysis, fluorescence quenching, cyclic voltammetry, and electron spin resonance spin trapping experiments.

Benzylidene ketones as visible light radical photoinitiator: The effects of electron-donating group and co-initiator

Benzylidene ketones (BK) are promising visible photoinitiator due to their facile synthesis and photochemical hydrogen atom transfer (HAT) reaction between tertiary amines. However, the effect of electron donating (ED) groups on their photophysical, electrochemical properties, and initiation efficiency were not fully disclosed. Moreover, it is not clear which co-initiator is suitable for BK. In this work, four benzylidene ketones bearing hydrogen (C3PH), methoxy (C3PO), methylthio (C3PS), and dimethylamine (C3PN) substitution were synthesized and characterized. BK’s maximum light absorption wavelengths increase following the order of C3PH < C3PO < C3PS < C3PN. Photopolymerization and steady state photolysis show that only C3PO and C3PS display higher HAT efficiency than C3PH, which is highly relating to the free energy change calculations results. Overall, C3PO is the most efficient one because good polymerization rate and final monomer conversion can be achieved. Triethanolamine is the best co-initiator because of its low oxidation potential and the lowest energy barrier to form a complex with C3PO.

Photopolymerization of acrylate resin and ceramic suspensions with benzylidene ketones under blue/green LED

Finding novel photoinitiators with photobleaching properties suitable for long-wavelength LED light sources is important for their potential use in the photocuring ceramic suspensions containing acrylate resin. Two D-π-A-π-D conjugated benzylidene ketones with visible light absorption (TPAK and CZK) were synthesized and evaluated as photoinitiators in the photocuring of acrylate resin and ceramic suspension under blue (460 nm)/green (520 nm) LED sources. Results showed that the two photoinitiators have high photoinitiating activity and can effectively produce thick-layer curing in acrylate resin and ceramic suspension due to their quick photobleaching properties under 460 nm and 520 nm LED light sources. The curing depth of the ceramic suspensions was measured as a function of the concentration of TPAK and CZK and the energy level of the LED light source. Jacob's equation was used to determine the critical energy Ec and depth sensitivity Dp of every suspension with different concentrations of benzylidene ketones.

An Experimental NMR and Semi-Empirical Theoretical Study of the Conformation of Styrylchromones and Styryl Alkyl or Aryl Ketones (Benzylidene Ketones)

The configurations and conformations of styrylchromones and benzylidene ketones were determined by NMR spectroscopy. The cyclisation of the former to xanthones was studied showing clear differences in reactivity. These structural aspects were rationalised with the help of AM1 calculations.

高活性ウラゾールを活用した新規ヘテロ環化合物の合成

The synthetic strategy of novel heterocyclic compounds from a series of urazoles (key compounds), which were prepared by addition-elimination reactions of benzylidene ketones with 4-phenyl-3H-1, 2, 4-triazole-3, 5 (4 H) -dione (PTAD), was described. Alcoholysis and aminolysis of the urazoles afforded intriguing tricyclic oxazolidinone derivatives (hetero analogues of triquinane sesquiterpenes). The reaction proceeded via Michael addition of nucleophiles to enone substructure, opening of the urazole ring by backbone participation and final skeletal rearrangements. This methodology was extended to one-pot syntheses of [4.3.3] propellane hetero analogues and 3-cyanoindole derivatives.While, oxime ethers of the key compounds were photochemically active to rearrange to triazinoindoles, via cleavage of N-N bond and subsequent skeletal rearrangement from a polar excited state. More active urazoles afforded surprisingly dimers and solvent-incorporated adducts (triazinoindolines) in a stereospecific fashion. On the contrary, sensitized reactions gave cyclobutane derivatives.

ChemInform Abstract: Formation of Tetracyclic Oxazolidinones from Cycloadducts of Benzylidene Ketones with 4‐Phenyl‐4,5‐dihydro‐3H‐1,2,4‐triazole‐3,5‐ dione (PTAD) by Base‐Promoted Backbone Participation and Rearrangement.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Formation of tetracyclic oxazolidinones from cycloadducts of benzylidene ketones with 4-phenyl-4,5-dihydro-3H-1,2,4-triazole-3,5-dione (PTAD) by base-promoted backbone participation and rearrangement

Alcoholysis and aminolysis of urazoles 4a–j prepared by the reactions of benzylidene ketones with 4-phenyl-4,5-dihydro-3H-1,2,4-triazole-3,5-dione (PTAD) afforded tricyclic oxazolidinone derivatives 5a��o in moderate yields (16–77%). The structure of compound 5b was confirmed by a single-crystal X-ray analysis. The reaction proceeded via opening of the urazole ring by initial Michael addition of nucleophiles (solvents) to the enone substructure, followed by participation of the carbonyl group and final skeletal rearrangements.

Effect of substrate structure on the liquid-phase regioselective 1,4-hydrogenation of E-benzylidene ketones on Rh/sepiolite catalyst

The liquid-phase catalytic hydrogenation of benzylidene ketones, in the p-XC 6H 4-CHCHCOR form ( E isomers; XH, Me, MeO, Cl; RMe, Et, n-Pr, i-Pr, t-Bu, n-Pe, Ph) was carried out using a sepiolite-supported rhodium catalyst (1 wt.% Rh) in methanol solvent under low hydrogen pressure (0.55 MPa) and at room temperature (298 K). The reactions were selective with respect to the formation of the conjugate reduction product ( p-XC 6H 4CH 2CH 2COR) although a very slight amount of benzyl ketone (hydrogenolysis of the CCl bond) is found in p-chlorobenzylidene ketones. The influence of both X and R substituents was analyzed by the Pavelich-Taft equation and both conjugative and steric effects of X and R groups were found to simultaneously influence the reaction process. A cis-concerted mechanism, including a transition state with some partially developed charge, is assumed for the hydrogenation of E-benzylidene ketones over Rh/ sepiolite catalysts. Here, the concerted character of the hydrogenation is considered as a reaction taking place in a single step on a rhodium surface site with three degrees of coordinative unsaturation.

ChemInform Abstract: Ethynologues of Triphenylmethane Dyes. Part 5. Diphenylmethane and Triphenylmethane Dye Ethynovinylogues with Absorption Bands in the Near‐Infrared.

AbstractThe benzylidene ketones (III), prepared from p‐dimethylaminobenzaldehyde (I) and the ketones (II), undergo condensation reaction with the phenylacetylides (IV), forming the alcohols (V) which are converted to the ethynyl vinyl carbenium salts (VI) upon treatment with perchloric acid.

Liquid-phase regioselective 1,4-hydrogenation of benzylidene ketones on rhodium-aluminum phosphate catalysts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLiquid-phase regioselective 1,4-hydrogenation of benzylidene ketones on rhodium-aluminum phosphate catalystsJ. A. Cabello, J. M. Campelo, A. Garcia, D. Luna, and J. M. MarinasCite this: J. Org. Chem. 1986, 51, 10, 1786–1790Publication Date (Print):May 1, 1986Publication History Published online1 May 2002Published inissue 1 May 1986https://doi.org/10.1021/jo00360a026RIGHTS & PERMISSIONSArticle Views235Altmetric-Citations31LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (728 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

The reaction of 1,1‐diethylaminoprop‐l‐yne with benzylidene ketones

Journal of Heterocyclic ChemistryVolume 10, Issue 2 p. 165-166 Note The reaction of 1,1-diethylaminoprop-l-yne with benzylidene ketones P. L. Myers, P. L. Myers Reckitt & Colman Pharmaceutical Division, Hull, HU8 7DS, EnglandSearch for more papers by this authorJ. W. Lewis, J. W. Lewis Reckitt & Colman Pharmaceutical Division, Hull, HU8 7DS, EnglandSearch for more papers by this author P. L. Myers, P. L. Myers Reckitt & Colman Pharmaceutical Division, Hull, HU8 7DS, EnglandSearch for more papers by this authorJ. W. Lewis, J. W. Lewis Reckitt & Colman Pharmaceutical Division, Hull, HU8 7DS, EnglandSearch for more papers by this author First published: April 1973 https://doi.org/10.1002/jhet.5570100206Citations: 11AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume10, Issue2April 1973Pages 165-166 RelatedInformation

Reaction of enamines with benzylidene ketones. Part II.

The reaction between cyclohexanone enamines and a variety of benzylidene ketones gives a dihydropyran derivative in each case. The benzopyrans from reactions of 1 -piperidinocyclohexene with chalcone and with dibenzylideneacetone are unstable and on heating readily rearrange into isomeric enamino-ketones (6) and (10). Recyclisation of 2-phenyl-2-(2-piperidinocyclohex-2-enyl)ethyl styryl ketone (10) gives 1,4-diphenyl-7b-piperidinoperhydrocyclobuta[de]naphthalen-2-one (11).