21969-11-9Relevant articles and documents
NMR Study of Substituent Effects in 4-Substituted and 4,4'-Disubstituted Diphenyl Sulphides
Chandrasekaran, R.,Perumal, S.,Wilson, D.A.
, p. 1001 - 1006 (1987)
The proton and carbon NMR spectra of nine 4-X-diphenyl sulphides (series 1), seven 4-X-4'-NO2-diphenyl sulphides (series 2) and eight 4,4'-X2-diphenyl sulphides (series 3) have been obtained.Correlation of the 13C chemical shifts with the appropriate substituent chemical shifts (SCS) for monosubstituted benzenes (Lynch plots) show an enhancement of substituent effect at C-1 (carbon para to the substituent) in series 1 ans 2, but not in series 3.The carbons of the unsubstituted ring in series 1 also correlate with Cp-SCS, with slopes of less than unity; correlation for C-1' has a negative slope.Dual substituent parameter (DSP) correlations of the 13C chemical shifts with ?I/?oR are good to exellent for all the carbons of series 1 compounds, except those ortho to the substituent X.The carbons meta to the substituent X correlate well, but with negative values for ρI and ρR, although showing a scattered Lynch plot.Similar correlations are found with some carbon shifts in series 2, and with C-1 shifts in series 3.It is concluded that (a) reverse resonance effects are operative at the position meta to the variable substituent by virtue of the sulphur substituent ortho to that carbon; (b) there is transmission of inductive (field) and resonance effects from one aryl ring to the other, except when both rings carry substituents of the same electronic character (series 3); (c) there is some evidence for ?-polarization in the unsubstituted phenyl ring of series 1 compounds.Key words 1H NMR 13C NMR Diphenyl sulphides substituent effects
Optimization of a urea-containing series of nicotinamide phosphoribosyltransferase (NAMPT) activators
Pinkerton, Anthony B.,Sessions, E. Hampton,Hershberger, Paul,Maloney, Patrick R.,Peddibhotla, Satyamaheshwar,Hopf, Meghan,Sergienko, Eduard,Ma, Chen-Ting,Smith, Layton H.,Jackson, Michael R.,Tanaka, Jun,Tsuji, Takashi,Akiu, Mayuko,Cohen, Steven E.,Nakamura, Tsuyoshi,Gardell, Stephen J.
, (2021/04/27)
NAD+ is a crucial cellular factor that plays multifaceted roles in wide ranging biological processes. Low levels of NAD+ have been linked to numerous diseases including metabolic disorders, cardiovascular disease, neurodegeneration,
CuMoO4 Bimetallic Nanoparticles, An Efficient Catalyst for Room Temperature C?S Cross-Coupling of Thiols and Haloarenes
Panigrahi, Reba,Sahu, Santosh Kumar,Behera, Pradyota Kumar,Panda, Subhalaxmi,Rout, Laxmidhar
, p. 620 - 624 (2019/12/27)
CuII catalyst is less efficient at room temperature for C?S cross-coupling. C?S cross-coupling by CuII catalyst at room temperature is not reported; however, doping of copper with molybdenum metal has been realized here to be more efficient for C?S cross-coupling in comparison to general CuII catalyst. The doped catalyst CuMoO4 nanoparticle is found to be more efficient than copper. The catalyst works under mild conditions without any ligand at room temperature and is recyclable and effective for a wide range of thiols and haloarenes (ArI, ArBr, ArF) from milligram to gram scale. The copper-based bimetallic catalyst is developed and recognized for C?S cross-coupling of haloarenes with alkyl and aryl thiols.
