7314-08-1Relevant academic research and scientific papers
Remote Substituent Effects on Methyl Torsional Barriers: trans-p-Amino-p'-methylstilbene
Yan, Shuxin,Spangler, Lee H.
, p. 3047 - 3052 (1995)
The expansion-cooled fluorescence excitation spectrum of trans-p-amino-p'-methylstilbene is presented.It displays several prominent low-frequency modes, including a progression in the methyl torsion.Fits of the torsional progression yield an S1 barrier of
Xanthate-mediated synthesis of (E)-alkenes by semi-hydrogenation of alkynes using water as the hydrogen donor
Luo, Xianglin,Chen, Xiuwen,Chen, Lu,Zhang, Kun,Li, Yibiao
supporting information, p. 2170 - 2173 (2019/02/24)
Semi-hydrogenation of alkynes is one of the most widely used methods for obtaining alkenes in laboratory preparation and in industry. Transition metal catalysts have been extensively studied for this transformation, but the tolerance of functional groups, such as pyridine,-OH,-NH2,-Bpin, and halides, and the toxicity of the trace amount of transition metal catalysts are still highly challenging. In this study, we report a general and robust strategy to achieve the semi-hydrogenation of alkynes using inexpensive and commercially available xanthate as the mediator. Mechanism studies support a non-radical process and H2O acts as the hydrogen donor.
Substituent effects on the 13C NMR chemical shifts of the imine carbon in N-(4-X-benzylidene)-4-(4-Y-styryl) anilines
Fang, Zhengjun,Cao, Chenzhong,Chen, Guanfan
, p. 1343 - 1350 (2013/08/24)
Long-range electronic substituent effects were targeted using the substituent dependence of δC(C=N), and specific cross-interactions were explored extendedly. A wide set of N-(4-X-benzylidene)- 4-(4-Y-styryl) anilines, p-X-C6H4
Catalytic activity of Pd(II) and Pd(II)/DAB-R systems for the Heck arylation of olefins
Grasa, Gabriela A.,Singh, Rohit,Stevens, Edwin D.,Nolan, Steven P.
, p. 269 - 279 (2007/10/03)
Palladium-catalyzed reactions of aryl bromides with various olefins involving Pd(II)/diazabutadiene (DAB-R) systems have been investigated. The scope of a coupling process using Pd(II) sources and an α-diimine as ligand in the presence of Cs2CO3 as base was tested using various substrates. The Pd(OAc)2/ DAB-Cy (1, DAB-Cy=1,4-dicyclohexyl-diazabutadiene) system presents the highest activity with respect to electron-neutral and electron-deficient aryl bromides in coupling with electron rich olefins. The synthesis and X-ray characterization of a Pd(II)-diazabutadiene ligand is reported. Extensive optimization experiments showed that another Pd(II) source, Pd(acac)2 (acac=acetylacetonate), proved to activate aryl bromides at high temperatures, low catalyst loadings when the appropriate concentration of nBu4NBr additive was employed. The effect of the DAB-Cy ligand is important at very low catalyst loadings and high temperatures. Pd(acac)2 and Pd(acac)2 /DAB-Cy precatalysts were very effective for the arylation of various olefins with aryl bromides with respect to reaction rate, catalyst loadings, and functional group tolerance.
Spectroscopic characterization by laser flash photolysis of electrophilic intermediates derived from 4-aminostilbenes. Stilbene "nitrenium" ions and quinone methide imines
Bose, Rohit,Ahmad, Abid R.,Dicks, Andrew P.,Novak, Michael,Kayser, Kelly J.,McClelland, Robert A.
, p. 1591 - 1599 (2007/10/03)
This paper reports the observation in water-acetonitrile solutions of two electrophiles derived from 4-amino- and 4-acetylaminostilbene carcinogens - the 'nitrenium' ion ArCH=CHC6H4-N+R and the quinone methide imine ArCHOH
Metabolic N-Hydroxylation. Use of Substituent Variation to Modulate the in Vitro Bioactivation of 4-Acetamidostilbenes
Hanna, Patrick E.,Gammans, Richard E.,Sehon, Russell D.,Lee, Man-Kil
, p. 1038 - 1044 (2007/10/02)
N-Hydroxylation is an obligate step in the bioactivation of carcinogenic aryl amides.Previous reports from this laboratory demonstrated that variation of the 4' substituent of trans-4-acetamidostilbene (1) has a marked effect on the rate of its in vitro m
