Photoinduced Cycloaddition Research Articles

Photoreaction of Skin‐sensitizing Trimethyl Psoralen with Lipid Membrane Models

The concerted photoreaction between trimethyl psoralen (TMP) and isomeric model compounds of oleic acid methyl ester (OAME) and eadilic acid methyl ester (EAME) are explored using density functional theory. The S(1) surfaces all reveal large barriers (25-31 kcal/mol) to reach the decay channels, whereas the S(2) surfaces differ considerably between the furan and pyrone side adducts. For the pyrone side adducts, a small barrier to reach the intersection between the S(1) and S(2) states is found, followed by a small second barrier on the S(1) surface to the low-lying decay channel. For the furan-side adducts, no such intersection between S(1) and S(2) is seen, which thus prevents these products from being formed in high yields. The photoinduced cycloaddition is more favorable between OAME and the pyrone side double bond of TMP than for any of the other systems, which agrees with the experimental findings that this is formed in the highest yield. The computed UV absorption spectra of TMP and the TMP(pyrone)-OAME cycloadduct agree well with the experimental spectra.

Photochromic Effects of an Anthracene Derivative in Polyurethane

ABSTRACT Segmented poly(ether urethanes) with anthracene built into the hard segment based on 4,4′-diphenylmethylene diisocyanate or hexamethylene diisocyante, 1,4-butanediol, 2,6-(dihydroxymethyl)anthracene, and poly(oxytetramethylene) soft segments were synthesized. The photo-induced cycloaddition of anthracene in these polyurethanes has been studied by UV-Vis spectroscopy. A reversible change of the refractive index of polymer films could be achieved.

Synthesis of Thienobenzofuranquinone Derivatives by Photoinduced and CAN-mediated 3+2-Type Cycloaddition Reactions

Photoinduced cycloaddition between ethyl 5-hydroxy-3-methyl-4,7-dioxo-4,7-dihydrobenzo[b]thiophene-2-carboxylate (la) and alkenes is reported to give ethyl 7-methyl-4,8-dioxo-2,3,4,8-tetrahydrothieno[2,3-f]benzofuran-6-carboxylates (2). Cerium(IV) ammonium nitrate (CAN)-mediated cycloaddition of ethyl 5-hydroxy-4,7-dioxo-4,7-dihydrobenzo[b]thiophene-2-carboxylates (1) to alkenes or phenylacetylene, giving ethyl 4,8-dioxo-4,8-dihydrothieno[2,3-f]benzofuran-6-carboxylate (2 or 4) and ethyl 4,5-dioxo-4,5-dihydrothieno[3,2-g]benzofuran-7-carboxylate derivatives (3 or 5), is also reported.

Photoinduced [2 + 2] cycloadditions (the Paterno–Büchi reaction) of 1H-1-acetylindole-2,3-dione with alkenes

Photoinduced cycloadditions of 1-acetylisatin (1) with alkenes 2–7 give spiroxetanes 8–21 respectively in moderate to high yields, displaying a typical triplet n–π* reactivity for 1. The regioselectivity and diastereoselectivity of the reactions depend on the reaction mechanism. In reactions with alkenes of high oxidation potential (2 and 4) where single-electron transfer (SET) processes with triplet excited 1 are not involved, the regioselectivity can be rationalized by consideration of frontier molecular orbital interactions of the two addends, and the Salem–Rowland rules for diradical intersystem crossing explains the diastereoselectivity. For the more electron-rich alkenes, e.g.5–7, SET processes with 31* and ion-radical pair formation are energetically feasible, and the cycloaddition regioselectivity is dependent on charge and spin-density distribution in the ion-radicals and the diastereoselectivity is also decided by ion-radical pair collapse.

Photoinduced Dimerization of ap-Phenylenediacrylic Acid Derivative in a Langmuir Monolayer Mixed with Stearic-d35Acid on a Water Surface

Photoinduced cycloaddition of a p-phenylenediacrylic acid derivative, 4-(4-(2-(decyloxycarbonyl)vinyl)cinnamoylamino)benzoic acid, was conducted successfully in a mixed Langmuir monolayer with stearic-d35 acid on a water surface at room temperature. The reaction process was investigated by UV−visible and infrared spectroscopy, gel permeation chromatography (GPC), and Brewster-angle microscopy (BAM). The product was identified as the cyclobutane dimer. The formation of the stable monolayer and the dimerization reaction on the water surface were evaluated at the molecular level by observation of the monolayer's behavior (surface pressure, monolayer area, and change of surface morphology). The BAM observation and GPC analysis of the photoproducts obtained under different states of the monolayer reveal that the molecular arrangement with higher mobility gives a much higher reaction speed.

Syntheses and electronic structures of benzannelated isoquinolinones and their photoinduced cycloaddition reactions with electron deficient alkenes †

Benzoxazolo[3,2-b]isoquinolin-11-ones 4, benzothiazolo[3,2-b]isoquinolin-11-one 5, benzimidazo[1,2-b]isoquinolin-11-ones 6 and isoquino[2,3-a][3,1]benzoxazine-5,12-dione 7 were synthesized by the reaction of homophthalic anhydride with the corresponding o-substituted anilines. Reaction mechanisms were investigated by isolation of the intermediate products under controlled reaction conditions. Electronic structures of 4a and 5 were investigated by ab initio calculations. Photoinduced [2+2] cycloaddition reactions of 4a and 5 with electron deficient alkenes (acrylonitrile, methyl acrylate, dimethyl fumarate and dimethyl maleate) gave cyclobutane products (36, 37 and 39–47 respectively). The regioselectivity in these photocycloadditions was examined by FMO interaction considerations. The mechanism of the cycloadditions was investigated by fluorescence quenching and triplet quenching experiments, solvent effect on the reaction and calculation of free energy change for electron transfer (SET) between the excited states of 4a (and 5) and the alkenes.

Light-switched metal-tunneling across a π-basic tube of 1,3-alternate-calix[4]arenes

Three 1,3-alternate-calix[4]arenes ( 1 ∼ 3 ) bearing two anthracenyl groups at one side and two propoxyl or ethoxyethoxyl groups at the other side were synthesized. The aim of this molecular design is to reversibly change the metal-binding ability of the anthracene-linked side through their photoinduced cycloaddition and reverse thermal decomposition. Since certain metal cations tend to pass from one side to the other side across a π-basic calix[4]arene tube, one can expect that a light-triggered metal tunneling for this molecule. In compounds 1 and 2 the rate of the metal tunneling was faster than the 1H NMR time-scale and the distribution of metal cations between two sides could not be determined. In a 3·Ag + complex the coalescence temperature appeared at −20°C and Ag + is bound to the ethoxyethoxyl side more than to the anthracenyl side in the dark. After photoirradiation Ag + was exclusively bound to the photocycloaddition side. These results support the view that compound 3 behaves like a mechanochemical “syringe”, the action of which is controllable by light.

Chemistry of silyl thioketones. Part 8. Photo-induced cycloadditions of silyl thioketones with olefins

Photo-induced cycloadditions of phenyl triphenylsilyl thioketone 1 with electron-poor olefins (acrylonitrile, methyl acrylate and cis- and trans-1,2-dichloroethene) gave silyl thietanes in a regio- and highly stereo-selective manner. In contrast, reaction with vinyl ethers gave thietanes without any regio- or stereo-control. Reaction with α-methylstyrene and 2,3-dimethylbut-2-ene gave open chain products. Desilylation of silyl thietanes occurs with prevalent inversion of configuration at the carbon bearing the silicon group.

ChemInform Abstract: Preparation of 2H‐Benzoxetes by Photoinduced (2 + 2) Cycloaddition of Quinone Methides, Accessible by Dimethyldioxirane (DMD) Oxidation of 2, 3‐Dimethylbenzofurans.

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.

Tetramethylene diradicals in the photoinduced cycloaddition and copolymerization of the styrene/acrylonitrile system

Le styrene excite forme par irradiation reagit avec l'acrylonitrile ou le styrene pour donner l'exciplexe . StAN . ou l'excimere . StSE . respectivement. Le diradical . TsAN . amorce preferentiellement la copolymerisation alors que . StSt . cyclise preferentiellement. La formation de ces diradicaux est demontree en etudiant les effets du solvant et du rapport molaire des 2 comonomeres

Photochemistry of epoxyquinone. 5. Photoinduced cycloadditions of epoxynaphthoquinone to aldehydes, ketones, and oxygen

Photochemistry of epoxyquinone. 5. Photoinduced cycloadditions of epoxynaphthoquinone to aldehydes, ketones, and oxygen

Photochemistry of epoxyquinones. Part 7. Photo-induced cycloaddition of 2,3-dimethyl-2,3-dihydro-2,3-epoxy-1,4-naphthoquinone to olefins

Irradiation of 2,3-dimethyl-2,3-dihydro-2,3-epoxy-1,4-naphthoquinone (1a) in benzene gave the carbonyl ylide (2a) or the 1,3-diradical (3a), which was trapped with a variety of olefins, including simple alkenes, cycloalkenes, aromatic olefins, allyl alcohols, electron-rich olefins, and electron-deficient olefins. The excited state of (1a) was quenched by electron-rich olefins presumably via charge-transfer, while (2a) or (3a) react most readily with electron-deficient olefins. Cycloaddition of (2a) or (3a) to cis- and trans-but-2-ene proceeded stereospecifically. Further irradiation of the primary adducts gave the spirophthalide (5) and the alkylidenephthalides Z-(7) and E-(7)via preferential α-cleavage at the more crowded side. On the basis of the evidence of quantum yields and triplet lifetimes, this preference is believed to arise from the different efficiencies of the radical recombination of possible biradicals.

Photoinduced cycloadditions of electron deficient nitrones to alkenes

Oxaziridines are proposed as intermediates in the photoinduced cycloadditions of electron deficient nitrones to dipolarophiles.

ChemInform Abstract: PHOTO‐INDUCED CYCLOADDITIONS OF EPOXYQUINONE TO ALDEHYDES AND KETONES

Chemischer InformationsdienstVolume 11, Issue 6 Preparative Organic Chemistry ChemInform Abstract: PHOTO-INDUCED CYCLOADDITIONS OF EPOXYQUINONE TO ALDEHYDES AND KETONES K. MARUYAMA, Search for more papers by this authorA. OSUKA, Search for more papers by this author K. MARUYAMA, Search for more papers by this authorA. OSUKA, Search for more papers by this author First published: February 12, 1980 https://doi.org/10.1002/chin.198006127AboutPDF 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 onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume11, Issue6February 12, 1980 RelatedInformation

Synthetic Photochemistry. XV. A Total Synthesis of Some Oxygenated Protoilludanes by an Application of Photo-Induced Cycloadditions

An effective preparation of protoilludanes was developed by use of two-fold photocycloadditions and methylation. Stereochemistry of the photocycloaddition processes was clarified on the basis of chemical transformations as well as the NMR evidence. Taking an advantage of this facile formation of the natural protoilludane ring derivation, some of the biogenetically significant oxygenated derivatives have been totally synthesized.

Photochemical reaction of duroquinone with allenes and ketenimines. Photoinduced cycloaddition and molecular rearrangement

Photochemical reaction of duroquinone with allenes and ketenimines. Photoinduced cycloaddition and molecular rearrangement

Photocycloadditions of p-quinones to ketenimines

Photo-induced cycloadditions of p-benzoquinone derivatives and 1,4-naphthoquinone to several ketenimines afforded 1 : 1 adducts. Two consecutive adducts, 2-imino-1-oxaspiro [3.5] nona-5,8-dien-7-ones and 1-aza spiro[3.5]nona-5,8-diene-2,7-diones, were obtained from these photolyses in moderate yields. Their structures, which had been postulated as intermediates in a similar reaction, were determined by physical and chemical methods. These two types of spiro-cyclohexa-2,5-dienone gave the rearranged products, 2,3-dihydro-5-hydroxy benzofuran-2-imines and 5-hydroxyindolin-2-ones, respectively, by Lewis-acid catalysed rearrangement.

Photo-induced cycloaddition of tetra-substituted p-quinones to diphenylketen

Photo-induced cycloadditions of the tetra-substituted p-quinones duroquinone, chloranil, and 9,10-anthraquinone to diphenylketen afford two types of adducts: the 1-oxaspiro[3.5]nona-5,8-diene-2,7-diones (3) and bicyclo[4.2.0]octa-5-ene-2,4,7-triones (4).

Photochemistry of epoxyquinones. 2. Photoinduced cycloaddition reactions of aryl- or alkyl-substituted 2,3-epoxy-2,3-dihydro-1,4-naphthoquinones with olefins

Photochemistry of epoxyquinones. 2. Photoinduced cycloaddition reactions of aryl- or alkyl-substituted 2,3-epoxy-2,3-dihydro-1,4-naphthoquinones with olefins

Photo-induced Cycloaddition of 1-Nitrocyclooctene and Cyclopentadiene

Abstract Irradiation of 1-nitrocyclooctene produces first the strained trans isomer, which in turn undergoes thermal Diels-Alder reaction with cyclopentadiene affording the tricyclic adduct.