4482-52-4Relevant academic research and scientific papers
Covenient Synthesis of β-Truxinic Acid via Photodimerization of p-Nitrophenyl Cinnamate in the Crystalline State
Nishikubo, Tadatomi,Takahashi, Eiji,Miyaji, Takatoshi,Iizawa, Takashi
, p. 3399 - 3400 (1985)
β-Truxinic acid was synthesized in extremely high yield via a topochemical photodimerization of p-nitrophenyl cinnamate crystals, followed by the hydrolysis of the obtained dimer.
Regioselective photodimerization of cinnamic acid in a micellar solution
Nakamura, Yushin
, p. 477 - 478 (1988)
Irradiation of trans-cinnamic acid (1) and its methyl ester (2) in 1% aq. cetyltirmethylammonium bromide gave dimeric products in 35 and 29% yields as a mixture of truxinic and truuxillic acids in a ratio of 19 : 1 and 3.8 : 1, respectively, while in homogeneous solutions (1) gave no photodimers and (2) gave dimeric products in 2.3% yield under similar reaction conditions.
Photocatalytic Oxidative [2+2] Cycloelimination Reactions with Flavinium Salts: Mechanistic Study and Influence of the Catalyst Structure
Hartman, Tomá?,Reisnerová, Martina,Chudoba, Josef,Svobodová, Eva,Archipowa, Nataliya,Kutta, Roger Jan,Cibulka, Radek
, p. 373 - 386 (2021/02/01)
Flavinium salts are frequently used in organocatalysis but their application in photoredox catalysis has not been systematically investigated to date. We synthesized a series of 5-ethyl-1,3-dimethylalloxazinium salts with different substituents in the positions 7 and 8 and investigated their application in light-dependent oxidative cycloelimination of cyclobutanes. Detailed mechanistic investigations with a coumarin dimer as a model substrate reveal that the reaction preferentially occurs via the triplet-born radical pair after electron transfer from the substrate to the triplet state of an alloxazinium salt. The very photostable 7,8-dimethoxy derivative is a superior catalyst with a sufficiently high oxidation power (E=2.26 V) allowing the conversion of various cyclobutanes (with Eox up to 2.05 V) in high yields. Even compounds such as all-trans dimethyl 3,4-bis(4-methoxyphenyl)cyclobutane-1,2-dicarboxylate can be converted, whose opening requires a high activation energy due to a missing pre-activation caused by bulky adjacent substituents in cis-position.
Donor-acceptor fluorophores as efficient energy transfer photocatalysts for [2 + 2] photodimerization
Chen, Feng,Chen, Hao,Liu, Xue-Fen,Luo, Shu-Ping,Ren, Chen-Chao,Wu, Qing-An,Xu, Liang-Xuan,Yu, Xiao-Cong
supporting information, p. 3707 - 3716 (2020/06/03)
Mild [2 + 2] photodimerization of enone substrates was induced by donor-acceptor fluorophores. Enone substrates were activated efficiently for anti-head to head dimerizations with a high yield (up to 83%) and high selectivity. The adjustable excited state potential also allows donor-acceptor fluorophores to be used for isomerization of the above substrates, confirming the potential of donor-acceptor fluorophores as energy transfer photocatalysts.
The photodimerisation of the α- and β-forms of trans-cinnamic acid: A study of single crystals by vibrational microspectroscopy
Atkinson, Samantha D.M.,Almond, Matthew J.,Hollins, Peter,Jenkins, Samantha L.
, p. 629 - 635 (2007/10/03)
Infrared and Raman microspectroscopy have been used to follow the photodimerisation reactions of single crystals, the α- and β-forms of trans-cinnamic acid. This approach allows the starting materials and products - α-truxillic acid that has Ci symmetry and β-truxinic acid, which has Cs symmetry - to be identified. It also allows the topotactic nature of the reaction to be confirmed. Attempts to produce the poorly-defined unreactive γ-form of trans-cinnamic acid resulted only in a mixture of the α- and β-forms. The findings suggest a wide role for these spectroscopic methods in monitoring solid-state organic reactions.
4,15-Diamino[2.2]paracyclophane, a reusable template for topochemical reaction control in solution
Zitt, Holger,Dix, Ina,Hopf, Henning,Jones, Peter G.
, p. 2298 - 2307 (2007/10/03)
An efficient synthesis of [2.2]paracyclophane-4,15-dicarboxylic acid (11) from [2.2]paracyclophane (8) has been developed. The diacid was converted via the diazide 14 into the 4,15-diisocyanato[2.2]paracyclophane (15), a versatile intermediate that could be transformed into many new pseudogeminally substituted derivatives of 8. For example, treatment of 15 with alcohols provided the carbamates 16 and 17. On treatment of 15 with diisopropylamine, the urea 18 was obtained, whereas reduction with lithium aluminium hydride afforded the cyclic urea 20. Hydrolysis of 15 furnished the diamine 19, which was used as a reusable spacer in a [2+2]photoaddition experiment. Thus, treatment of 19 with trans-cinnamoyl chloride (25) provided the bis(amide) 26, which on irradiation in acetone ring-closed to give the cyclobutane 28. Saponification of this yielded 3,4-diphenyl-1,2-cyclobutanedicarboxylic acid (27, β-truxinic acid) and returned the spacer system 19, both in quantitative yield. The X-ray structures of 15 and 20 are reported. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
Photodimerization of cinnamic acids controlled by molecular assemblies of surfactant amine N-oxides
Nakamura, Tomotaka,Takagi, Katsuhiko,Itoh, Mariko,Fujita, Kaori,Katsu, Hiroyuki,Imae, Toyoko,Sawaki, Yasuhiko
, p. 2751 - 2755 (2007/10/03)
UV irradiation of cinnamic acids 1 involving a complex with surfactant amine N-oxides (CnDAO, n = 12, 14 and 16) as vesicles in water leads to the formation of cyclodimers (i.e. β-, δ-truxinic and/or α-truxillic acids ?). Decreasing the molar ratios of 1 to CnDAO causes the vesicles to transform into rod-like micelles and the yield of the cyclodimers decreases. The addition of HCl or NaOH to aqueous solutions of 1 and CnDAO brings about sharp changes in the self-assembly structures from vesicles to micro emulsions or rod-like micelles, accompanied by a change in product distribution in the photolysis of the complex 1. Upon addition of photoinactive carboxylic acids, phenylpropionic and palmitic acids to the 1 and C16DAO system, the rod-like micelles change into vesicles by formation of a complex with C16DAO leading to the observation of a dilution effect in the photodimerization upon addition of phenylpropionic acid. However, no dilution effect is observed for the palmitic acid. This is found to be attributable to the difference in degrees of mixing of 1 with the acids in the vesicles. These results show that photodimerization of 1 incorporated in CnDAO is controlled by a variety of molecular assemblies, i.e. rod-like micelles and homogeneous or heterogeneous vesicles.
Stereoselectivity control of [2 + 2] photocycloaddition by changing site distances of hydrotalcite interlayers
Shichi, Tetsuya,Takagi, Katsuhiko,Sawaki, Yasuhiko
, p. 2027 - 2028 (2007/10/03)
Stereoselectivity of photocyclodimers of unsaturated carboxylates is shown to be controlled by changing the site distances of clay interlayers.
Photochemical cyclodimerization of cinnmamic acids included in surfactant amine oxides
Takagi,Nakamura,Katsu,Itoh,Sawaki,Imae
, p. 135 - 138 (2007/10/03)
Photocyclodimerization of unsubstituted and p-methoxy substituted cinnamic acids incorporated in micelles, vesicles or microemulsions formed by dodecyl-(C12DAO) and hexadecyl-dimethylamine oxides (C16DAO) has been studied in water. The dimerization proceeds in the vesicle much more efficiently than in the micelles with preferable formation of head-to-head dimers. The photoreactivity and the stereochemistry of cyclodimers are affected by structural change of the molecular aggregates.
Control of Solid-State Photodimerization of trans-Cinnamic Acid by Double Salt Formation with Diamines
Ito, Yoshikatsu,Borecka, Bozena,Trotter, James,Scheffer, John R.
, p. 6083 - 6086 (2007/10/02)
By double salt formation, diamines can steer the solid-state photodimerization of trans-cinnamic acid (1).Thus, the yields for the photodimerization were significant only in three double salts, i.e., the ones with tn and t- and c-chxn, which are assumed to have an overlap structure.The resultant photodimer is generally β-truxinic acid, although in one case, ε-truxillic acid was formed. α-Truxillic acid was not produced from any of the double salts studied.The X-ray crystal structures of three double salts of low photoreactivity (1*en, 1*pen, 1*hen) were consistent with Schmidt's rule.
