Search results
Search for "photochemistry" in Full Text gives 139 result(s) in Beilstein Journal of Organic Chemistry.
Photoinduced electron-transfer chemistry of the bielectrophoric N-phthaloyl derivatives of the amino acids tyrosine, histidine and tryptophan
Beilstein J. Org. Chem. 2011, 7, 518–524, doi:10.3762/bjoc.7.60
- Axel G. Griesbeck Jorg Neudorfl Alan de Kiff University of Cologne, Department of Chemistry, Organic Chemistry, Greinstr. 4, D-50939 Köln, Germany; Fax: +49(221)470 5057 10.3762/bjoc.7.60 Abstract The photochemistry of phthalimide derivatives of the electron-rich amino acids tyrosine, histidine
- Norrish cleavage. The tryptophan derivative 10 is photochemically inert and shows preferential decarboxylation only when induced by intermolecular PET. Keywords: amino acids; decarboxylation; electron transfer; photochemistry; phthalimides; Introduction Phthalimides are versatile electron acceptors in
- +, electronically excited phthalimides are potent electron acceptors [2]. The rich photochemistry of this chromophore has recently been reviewed [3][4]. Intramolecular hydrogen abstraction is an archetype process for electronically excited carbonyl groups (Norrish type II reaction). The 1,4-biradicals formed by γ
Supramolecular FRET photocyclodimerization of anthracenecarboxylate with naphthalene-capped γ-cyclodextrin
Beilstein J. Org. Chem. 2011, 7, 290–297, doi:10.3762/bjoc.7.38
- γ-cyclodextrin; FRET sensitization; photochirogenesis; photocyclodimerization; Introduction Chiral photochemistry, often characterized by low optical yields, remains a great challenge for chemists [1][2][3]. This situation reflects primarily the difficulty in efficiently transferring the
- stereochemical information of the chiral source to the substrate in the electronically excited state. Thus, a supramolecular approach in chiral photochemistry could be a promising strategy for critically controlling the stereochemical outcome via intimate, long-lasting contacts with the photosubstrate through
Effects of anion complexation on the photoreactivity of bisureido- and bisthioureido-substituted dibenzobarrelene derivatives
Beilstein J. Org. Chem. 2011, 7, 278–289, doi:10.3762/bjoc.7.37
- formation of the dibenzosemibullvalene with moderate stereoselectivity (68:32 er). In contrast, the thioureido derivative showed no such effect upon complexation of chiral anions. Keywords: dibenzobarrelenes; dibenzosemibullvalenes; di-π-methane rearrangement; supramolecular photochemistry; (thio)urea
Photoinduced homolytic C–H activation in N-(4-homoadamantyl)phthalimide
Beilstein J. Org. Chem. 2011, 7, 270–277, doi:10.3762/bjoc.7.36
- for the abstraction. Keywords: homoadamantanes; photoinduced H-abstraction; phthalimides; Introduction Since the pioneering work of Ciamican and Paterno [1][2], the photochemistry of ketones has been intensively studied [3][4][5][6]. One important chemical pathway for the deactivation of ketones
- type II reaction [18][19][20]. The photochemistry of phthalimide derivatives is often similar to that of simple ketones [21][22][23][24][25][26][27][28][29][30][31][32][33]. For example, phthalimide derivatives in the electronically excited state abstract H-atoms from alcohols to give reduction
- (Scheme 1) [51]. The mechanism of the photoinduced domino reaction was investigated and it was found that it probably takes place from a higher excited triplet state or the singlet state [52]. Herein, we report the synthesis and photochemistry of a phthalimide derivative of homoadamantane 5. The research
Photocycloaddition of aromatic and aliphatic aldehydes to isoxazoles: Cycloaddition reactivity and stability studies
Beilstein J. Org. Chem. 2011, 7, 127–134, doi:10.3762/bjoc.7.18
- ; photochemistry; Introduction Photochemical [2 + 2] cycloadditions are among the most efficient photoreactions and are used in numerous synthetic applications due to the generation of highly reactive four-membered rings. An important example is the photocycloaddition of electronically excited carbonyl compounds
- unstable. Photochemistry of the isoxazoles 7a–h: test reactions The isoxazoles 7a–e were irradiated in the presence of benzaldehyde or propionaldehyde as model compounds for aromatic and aliphatic carbonyl compounds, respectively, at λ = 300 nm in perdeuterated acetonitrile. 1H NMR studies showed that the
Synthesis of cationic dibenzosemibullvalene-based phase-transfer catalysts by di-π-methane rearrangements of pyrrolinium-annelated dibenzobarrelene derivatives
Beilstein J. Org. Chem. 2011, 7, 119–126, doi:10.3762/bjoc.7.17
- pyrrolidinium-annelated dibenzosemibullvalene may act as phase-transfer catalyst in alkylation reactions. Keywords: di-π-methane rearrangement; dibenzobarrelenes; dibenzosemibullvalenes; phase-transfer catalysis; photochemistry; polycylic compounds; Introduction The di-π-methane (DPM) rearrangement is among
Photocycloadditions and photorearrangements
Beilstein J. Org. Chem. 2011, 7, 111–112, doi:10.3762/bjoc.7.15
- shifts are known from carbonyl photochemistry, di-π-methane and oxa-di-π-methane rearrangements are processes that can occur with a remarkable increase in molecular and stereochemical complexity, as can meta arene photocycloadditions. It was a great pleasure to act as the editor of this Thematic Series
A new fluorescent chemosensor for fluoride anion based on a pyrrole–isoxazole derivative
Beilstein J. Org. Chem. 2011, 7, 46–52, doi:10.3762/bjoc.7.8
- Zhipei Yang Kai Zhang Fangbin Gong Shayu Li Jun Chen Jin Shi Ma Lyubov N. Sobenina Albina I. Mikhaleva Guoqiang Yang Boris A. Trofimov Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190
Synthesis of spiroannulated and 3-arylated 1,2,4-trioxanes from mesitylol and methyl 4-hydroxytiglate by photooxygenation and peroxyacetalization
Beilstein J. Org. Chem. 2010, 6, No. 61, doi:10.3762/bjoc.6.61
- University of Cologne for a start-up grant. Biological testing was performed in South-Korea. AGG is recipient of the 2009 Honda-Fujishima award (Asian Photochemistry Association) for the antimalarial trioxane research.
Anthracene functionalized terpyridines – synthesis and properties
Beilstein J. Org. Chem. 2010, 6, No. 54, doi:10.3762/bjoc.6.54
- (terpyridine)complexes 6a–b. Irradiation experiments were carried out with both the free ligands and an iron(II)-complex in order to investigate the photochemistry of the compounds. Keywords: anthracene; coordination chemistry; photochemistry; terpyridine; Introduction 2,2′:6′,2″-Terpyridines have been of
- terpyridine derivatives in photochemistry, we focused our attention on the synthesis and studies of potentially photoswitchable terpyridine ligands. The synthesis of bisterpyridines linked by a diazogroup has been reported [7][8]. As well as the connection of terpyridines to spiropyran moieties [9] and
- , and investigations regarding their photochemistry. Results and Discussion Synthesis of anthracene functionalized terpyridines We synthesized the terpyridine-4,4″-diacid 3, starting from methyl 2-acetylisonicotinate (1) and 4-tert-butylbenzaldehyde (2), by a one-pot combination of a Kröhnke type
A perfluorocyclopentene based diarylethene bearing two terpyridine moieties – synthesis, photochemical properties and influence of transition metal ions
Beilstein J. Org. Chem. 2010, 6, No. 53, doi:10.3762/bjoc.6.53
- photochemistry, we focused our attention on the synthesis and studies of photoswitchable terpyridine ligands. The synthesis of bisterpyridines linked by a diazogroup has been reported [7][8], as well as the connection of terpyridines to spiropyran moieties [9]. There have also been recent reports about
- terpyridines linked to dithienylethenes [10][11]. Herein we report the synthesis of terpyridine functionalized diarylethenes based on perfluorocyclopentene, their photochemistry and investigations regarding the influence of transition metals. Results and Discussion Synthetic key steps The basic photochromic
Synthesis of novel photochromic pyrans via palladium- mediated reactions
Beilstein J. Org. Chem. 2009, 5, No. 25, doi:10.3762/bjoc.5.25
- starting material and product under the harsh reaction conditions. All attempts to use MeOH in THF under similar conditions failed to produce detectable amounts of the desired methyl ester. Photochemistry of benzopyrans: Compound 5a Photophysical properties of the novel pyrans are exemplified with compound
- related systems [20]. The photochemistry of the investigated benzopyran 5a may be summarized as follows: as known from the literature [32], a very short-lived excited state is observed after photoexcitation into the S1-band, which decays on a time-scale < 1 ps. The molecule has reached the open form with
Reversible intramolecular photocycloaddition of a bis(9-anthrylbutadienyl)paracyclophane – an inverse photochromic system. (Photoactive cyclophanes 5)
Beilstein J. Org. Chem. 2009, 5, No. 20, doi:10.3762/bjoc.5.20
- photochemistry 3.1 Electronic absorption spectra The electronic absorption spectra of 2 in methylcyclohexane (MCH) and acetonitrile are represented in Figure 6. One notes that the lowest energy band (λmax = 400 nm with a tail down to 480 nm) is clearly red-shifted as compared to those of all the cinnamophane
EcoScale, a semi- quantitative tool to select an organic preparation based on economical and ecological parameters
Beilstein J. Org. Chem. 2006, 2, No. 3, doi:10.1186/1860-5397-2-3
- , the application of unconventional techniques such as microwave irradiation, ultrasound or photochemistry, and the need for an inert atmosphere, especially in a glove box, downgrade the overall quality of the synthesis. 5. Temperature/time The reaction temperature and time are closely related. In an
Other Beilstein-Institut Open Science Activities
