7370-24-3Relevant articles and documents
A new insight into the push-pull effect of substituents via the stilbene-like model compounds
Cao, Chaotun,Cao, Chenzhong,Zeng, Zhao
, (2022/02/01)
In this paper, authors report on 1-pyridyl-2-arylethenes, 1-furyl-2-arylethylenes, 1,2-diphenylpropylenes and substituted cinnamyl anilines as stilbene-like model compounds to investigate the factors dominating the push-pull effect of substituents via usi
Determination and application of the excited-state substituent constants of pyridyl and substituted phenyl groups
Cao, Chao-Tun,Yan, Lu,Cao, Chenzhong
supporting information, (2021/05/21)
Thirty six 1-pyridyl-2-arylethenes XCH=CHArY (abbreviated XAEY) were synthesized, in which, X is 2-pyridyl, 3-pyridyl and 4-pyridyl and Y is OMe, Me, H, Br, Cl, F, CF3, and CN. Their ultraviolet absorption spectra were measured in anhydrous ethanol, and their wavelengths of absorption maximum λmax were recorded. Also, the 234 λmax values of 1-substituted phenyl-2-arylethylene compounds (XAEY, where X is substituted phenyl) were collected. The excited-state substituent constants (Formula presented.) of three pyridyl groups and 23 substituted phenyl groups (total of 26) were obtained by means of curve-fitting method. Taking the λmax values of 358 samples of bi-arylethene derivatives as a data set and 126 samples of bi-aryl Schiff bases (including nine compounds synthesized by this work) as another data set, quantitative correlation analyses were performed by employing the obtained (Formula presented.) as a parameter, and good results were obtained for the two data sets. The reliability of the obtained (Formula presented.) values was verified. The results of this paper can provide excited-state substituent constants for the study and application of optical properties of conjugated organic compounds containing aryl groups.
Palladium(ii) ligated with a selenated (Se, CNHC, N-)-type pincer ligand: An efficient catalyst for Mizoroki-Heck and Suzuki-Miyaura coupling in water
Sharma, Kamal Nayan,Satrawala, Naveen,Srivastava, Avinash Kumar,Ali, Munsaf,Joshi, Raj Kumar
, p. 8969 - 8976 (2019/10/28)
A new 1-[N-benzylacetamido]-3-[1-(2-phenylselenylethyl)]benzimidazolium chloride (L), the precursor of a novel (Se, CNHC, N-)-type pincer ligand (L) was synthesised in high yield through a sequence of consecutive reactions of 1H-benzimidazole with ethylene dichloride, sodium selenophenolate, and N-benzyl-2-chloroacetamide. The palladium-promoted reaction of L with PdCl2 resulted in a moisture- and air-insensitive complex [Pd(L-H2Cl)Cl] (1), which demonstrated outstanding catalytic potential for Mizoroki-Heck coupling of aromatic bromides and chlorides (with yields up to 94% and 70%, respectively) at very low catalyst loading (0.2 mol%) and under mild reaction conditions in water. The complex (1) was also investigated for Suzuki-Miyaura coupling and found to be selectively efficient (yields up to 94%) for Suzuki-Miyaura coupling of aromatic bromides at 0.01 mol% of 1 in water. All coupling reactions were carried out in the green and economical solvent, water, which is highly desirable for bulk synthesis of complex molecules in industry. During the catalytic process, complex 1 converted into PdSe nanoparticles (NPs, size range 5-6 nm) in situ. The morphology and composition of these NPs were analysed through high-resolution transmission electron microscopy and transmission electron microscopy-energy dispersive X-ray spectroscopy, respectively. The core-level, X-ray photoelectron spectroscopy analysis confirmed the presence of stable Pd0 and Pd2+ oxidation states in these PdSe NPs. Based on further experimental investigations, these nanoparticles were found to work as a stock of true catalytic species. The hot filtration test, as well as the two-phase test, confirmed the largely homogeneous nature of the catalytic process, which probably proceeds by leaching of solution-phase Pd species from these NPs.
Direct Wittig Olefination of Alcohols
Li, Qiang-Qiang,Shah, Zaher,Qu, Jian-Ping,Kang, Yan-Biao
, p. 296 - 302 (2018/02/19)
A base-promoted transition metal-free approach to substituted alkenes using alcohols under aerobic conditions using air as the inexpensive and clean oxidant is described. Aldehydes are relatively difficult to handle compared to corresponding alcohols due to their volatility and penchant to polymerize and autoxidize. Wittig ylides are easily oxidized to aldehydes and consequently form homo-olefination products. By the strategy of simultaneously in situ generation of ylides and aldehydes, for the first time, alcohols are directly transferred to olefins with no need of prepreparation of either aldehydes or ylides. Thus, the di/monocontrollable olefination of diols is accomplished. This synthetically practical method has been applied in the gram-scale synthesis of pharmaceuticals, such as DMU-212 and resveratrol from alcohols.
Preparation of Vinyl Arenes by Nickel-Catalyzed Reductive Coupling of Aryl Halides with Vinyl Bromides
Liu, Jiandong,Ren, Qinghua,Zhang, Xinghua,Gong, Hegui
, p. 15544 - 15548 (2016/12/09)
This work emphasizes the synthesis of substituted vinyl arenes by reductive coupling of aryl halides with vinyl bromides under mild and easy-to-operate nickel-catalyzed reaction conditions. A broad range of aryl halides, including heteroaromatics, and vinyl bromides were employed to yielding products in moderate to excellent yields with high functional-group tolerance. The nickel-catalytic system displays good chemoselectivity between the two C(sp2)-halide coupling partners, thus demonstrating a mechanistic pathway distinct from other stepwise protocols.
Br?nsted acid-catalysed conjugate addition of photochemically generated α-amino radicals to alkenylpyridines
Hepburn, Hamish B.,Melchiorre, Paolo
, p. 3520 - 3523 (2016/03/04)
The conjugate addition of α-amino radicals to alkenylpyridines has been accomplished by the synergistic merger of Br?nsted acid and visible light photoredox catalysis. Key to reaction development was the protonation of the alkenylpyridines that transientl
Palladium-Catalyzed Oxidative Heck Coupling of Vinyl Pyridines with Aryl Boronic Acids
Chen, Shanshan,Zhang, Xiuli,Chu, Mingjie,Gan, Xiaoping,Lv, Xianhai,Yu, Jie
supporting information, p. 791 - 796 (2015/03/30)
An efficient methodology has been developed for the oxidative cross-coupling of vinyl pyridine with various boronic acids catalyzed by palladium. In this reaction, vinyl pyridines reacted with various aryl boronic acids in the presence of 10 mol% palladium(II) trifluoroacetate, 10 mol% 1,10- phenanthroline, and 1 equivalent silver(I) oxide, to give the corresponding aryl vinyl pyridine products as a single stereoisomer, with N,N-dimethylformamide as the solvent and under 1 atmosphere of oxygen gas. The aryl vinyl pyridine products were obtained in moderate to good yields after 24 hours. A mechanism for the reaction is proposed.
Lewis-acid-catalyzed benzylic reactions of 2-methylazaarenes with aldehydes
Mao, Dan,Hong, Gang,Wu, Shengying,Liu, Xin,Yu, Jianjun,Wang, Limin
, p. 3009 - 3019 (2014/05/20)
Lewis-acid-catalyzed benzylic reactions of 2-methylazaarenes with aldehydes have been investigated. Series of azaarene derivatives were afforded by this reaction. 2-(Pyridin-2-yl)ethanols with common substituents were formed through the LiNTf2-promoted aldol reaction for the first time. 2-Alkenylpyridines, exclusively in the form of the E isomers, were synthesized in the presence of LiNTf2 cooperated with H2NTf. In the presence of La(Pfb)3 as catalysis, 2-alkenylquinolines were obtained in high yields through the reactions between 2-methylquinolines and aldehydes under air.
Heck cross-coupling of vinyl heteroaromatic compounds with aryl and heteroaryl halides using Pd(II) complex under phosphine-free conditions
Annapurna, Manne,Vishnuvardhan Reddy,Singh, Surya Prakash,Kantam, Mannepalli Lakshmi
, p. 10940 - 10945 (2014/01/06)
The palladium-catalyzed cross-coupling reaction of vinyl heteroaromatic compounds with aryl bromides and heteroaryl bromides is described using air and moisture stable N,N′,N″,O-tetrafunctional Pd catalyst under phosphine-free conditions. As a result a variety of trans-1,2-disubstituted vinyl heterocycles were obtained in high to good yields.
1,2,3-Triazol-5-ylidene-palladium complex catalyzed Mizoroki-Heck and Sonogashira coupling reactions
Inomata, Sayuri,Hiroki, Hidekatsu,Terashima, Takahiro,Ogata, Kenichi,Fukuzawa, Shin-Ichi
experimental part, p. 7263 - 7267 (2011/10/08)
The bis-1,4-dimesityl-1,2,3-triazol-5-ylidene-palladium complex (1a) successfully catalyzes the Mizoroki-Heck and Sonogashira coupling reactions with aryl bromides to give the corresponding alkenes and alkynes, respectively, in good to excellent yields. In the Mizoroki-Heck reaction, electron-rich, electron-poor, and functionalized aryl bromides and alkenes are tolerated, while the substrates are limited to electron-poor aryl halides in the Sonogashira coupling reaction. The palladium complex also catalyzes cross-coupling reactions with aryl chlorides to give higher yields of products than does the bis-IMes-Pd complex analogue (2), under specific conditions.
