1242772-11-7Relevant academic research and scientific papers
Two-Step Synthesis of (Z)-3-Aryl-5-(arylmethylidene)butenolides by an Ivanov Reaction/Silver(I)-Catalyzed Lactonization/In Situ Dehydration Sequence
Hermann, David,Arican, Deniz,Brückner, Reinhard
, p. 326 - 352 (2017)
A stereoselective synthesis of the title compounds was developed. Hexane- and amine-free THF solutions of α-lithiated lithium arylacetates ('arylacetic acid dianions') were aldol-added to 3-arylpropynals. This gave 2,5-diaryl-3-hydroxypent-4-ynoic acids with up to a 72:28 preference for the anti-diastereomer (27 examples + 1 exception). When treated with Ag2CO3 (1-20 mol%) in DMF at room temperature for 2.5 days, the respective mixtures underwent regio- and stereoselective lactonizations followed by an in situ dehydration. Thereby 3-aryl-5-(arylmethylidene)butenolides were obtained with a Z-configuration of the oxygenated C=C bond. Their overall yields ranged from 46% to 83% (1 exception: 28%). Three 3-aryl-5-(arylmethylidene)butenolides contained a C-Br and/or a C-I bond. They allowed a subsequent Pd-catalyzed C-C coupling, which furnished follow-up butenolides.
Rhodium-Catalyzed 1,1-Hydroacylation of Thioacyl Carbenes with Alkynyl Aldehydes and Subsequent Cyclization
Zhou, Bingnan,Wu, Qiuyue,Dong, Ziyang,Xu, Jiaxi,Yang, Zhanhui
supporting information, p. 3594 - 3599 (2019/05/24)
A rhodium-catalyzed 1,1-hydroacylation of thioacyl carbenes with alkynyl and alkenyl aldehydes and subsequent 6-endo-trig/dig cyclization are realized, giving structurally diverse 4H-thiopyran-4-ones and 2,3-dihydro-4H-thiopyran-4-ones in moderate to good yields. The oxidative addition of Rh(I) to aldehydes is proposed to be the turnover-limiting step. Manipulations of estrones demonstrate the applications of our formal (3 + 3) transannulations in the structural modifications of natural products.
N,N′-Dibutylbarbituric acid as an acceptor moiety in push-pull chromophores
Klikar, Milan,Bures, Filip,Pytela, Oldrich,Mikysek, Tomas,Padelkova, Zdenka,Barsella, Alberto,Dorkenoo, Kokou,Achelle, Sylvain
supporting information, p. 4230 - 4240 (2013/12/04)
Twelve novel D-π-A chromophores with the N,N′-dibutylbarbituric acid acceptor, the N,N-dimethylamino donor and a systematically extended π-linker were synthesized. The extent of intramolecular charge-transfer, structure-property relationships and nonlinear optical properties were further investigated by X-ray analysis, electrochemistry, UV/Vis absorption spectra, calculations and EFISH experiments.
Efficient one-pot preparation of methylthio arylbutadiynes by double elimination protocol
Su, Qiong,Yan, Hong,Gao, Shi-Chao,Xie, De-Xun,Cai, Qing-Yun,Shao, Guang,Peng, Zhi-Hong,An, De-Lie
supporting information, p. 2648 - 2655 (2013/07/26)
A novel and efficient method for preparation of methylthio arylbutadiynes (Ar-C≡C-C≡C-SCH3) was described, and a series of compounds have been expediently obtained by the one-pot protocol starting from methylthiomethyl phenyl sulfone (MP-S) and arylpropargyl aldehydes. The mechanism was discussed on the basis of trapping and characterization of key intermediates. The results from experiments indicated that the reaction involved the initial nucleophilic addition of MP-S to arylpropargyl aldehydes to produce an intermediate carrying two leaving groups and subsequent double elimination reactions. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
Synthesis and spectroscopic study of phenylenee (poly) ethynylenes substituted by amino or amino/cyano groups at terminal(s):Electronic effect of cyano group on charge-transfer excitation of acetylenic φ-systems
Fang, Jing-Kun,An, De-Lie,Wakamatsu, Kan,Ishikawa, Takeharu,Iwanaga, Tetsuo,Toyota, Shinji,Akita, Shin-Ichi,Matsuo, Daisuke,Orita, Akihiro,Otera, Junzo
supporting information; experimental part, p. 5479 - 5485 (2010/08/19)
To gain insight into substituent electronic effect on charge-transfer excitation of acetylenic p-systems, phenylenee(poly)ethynylenes substituted by Ph2N or Ph2N/cyano groups were synthesized by combination of Sonogashira coupling and double elimination protocol of b-substituted sulfones.These substituted phenyleneethynylenes showed large molar absorption coefficients 3, and emitted strong fluorescence upon UV light irradiation.Phenylenee(poly)ethynylenes, which involve butadiyne or hexatriyne motifs, emitted fluorescence in remarkably lower fluorescence quantum yields FF as their polyethynylene motifs e(C^C)ne expanded.The drastic decrease of fluorescence quantum yields FF were explained in terms of increasing nonradiative reaction rate constants knr, which had been determined by the corresponding fluorescence quantum yields F F and lifetime values s.The emission underwent a large bathochromic shift in polar solvents because the charge-separated excited state is more stabilized than the ground state.Comparison of slope values r in Lippert/Mataga plot for the Ph2N and Ph2N/cyano-substituted phenylenee(poly)ethynylenes revealed that the latter underwent large change of dipole moments upon photo-excitation although highly expanded acetylenic p-systems with cyano group did little.
