57728-64-0Relevant academic research and scientific papers
Mild, Selective Ru-Catalyzed Deuteration Using D2O as a Deuterium Source
Eisele, Pascal,Ullwer, Franziska,Scholz, Sven,Plietker, Bernd
, p. 16550 - 16554 (2019/12/11)
A method for the selective deuteration of polyfunctional organic molecules using catalytic amounts of [RuCl2(PPh3)3] and D2O as a deuterium source is presented. Through variation of additives like CuI, KOH, and various amounts of zinc powder, orthogonal chemoselectivities in the deuteration process are observed. Mechanistic investigation indicates the presence of different, defined Ru-complexes under the given specific conditions.
The α-effect in hydrazinolysis of 4-chloro-2-nitrophenyl x-substituted-benzoates: Effect of substituent x on reaction mechanism and the α-effect
Kim, Min-Young,Kim, Tae-Eun,Lee, Jieun,Um, Ik-Hwan
, p. 2271 - 2276 (2014/09/29)
Second-order rate constants (kN) have been measured spectrophotometrically for the reaction of 4-chloro-2- nitrophenyl X-substituted-benzoates (6a-6h) with a series of primary amines including hydrazine in 80 mol % H2O/20 mol % DMSO at 25.0°C. The Bronsted-type plot for the reaction of 4-chloro-2-nitrophenyl benzoate (6d) is linear with βnuc = 0.74 when hydrazine is excluded from the correlation. Such a linear Bronsted-type plot is typical for reactions reported previously to proceed through a stepwise mechanism in which expulsion of the leaving group occurs in the rate-determining step (RDS). The Hammett plots for the reactions of 6a-6h with hydrazine and glycylglycine are nonlinear. In contrast, the Yukawa-Tsuno plots exhibit excellent linear correlations with ?X = 1.29-1.45 and r = 0.53-0.56, indicating that the nonlinear Hammett plots are not due to a change in RDS but are caused by resonance stabilization of the substrates possessing an electron-donating group (EDG). Hydrazine is ca. 47-93 times more reactive than similarly basic glycylglycine toward 6a-6h (e.g., the α-effect). The α-effect increases as the substituent X in the benzoyl moiety becomes a stronger electronwithdrawing group (EWG), indicating that destabilization of the ground state (GS) of hydrazine through the repulsion between the nonbonding electron pairs on the two N atoms is not solely responsible for the substituent-dependent α-effect. Stabilization of transition state (TS) through five-membered cyclic TSs, which would increase the electrophilicity of the reaction center or the nucleofugality of the leaving group, contributes to the α-effect observed in this study.
Study of synthesis and cardiovascular activity of some furoxan derivatives as potential NO-donors
Mu, Li,Feng, Si-Shen,Go, Mei Lin
, p. 808 - 816 (2007/10/03)
A series of hybrid molecules incorporating the furoxan and nicorandil moieties were designed as potential NO donors with cardiovascular and cerebrovascular activities. Thirty-six target molecules were successfully synthesized by conventional methods and characterized by infrared spectroscopy, 1H-NMR spectroscopy and high resolution mass spectra. The compounds were tested for their effects on KCl-induced contraction of rabbit thoracic aorta whose endothelium was denuded. Eight compounds were found to reduce KCl-induced contraction by more than 30% at 10 μM. All except one of these compounds are characterized by the presence of electron withdrawing groups in the phenyl ring attached via an amide or ester linkage to the furoxan moiety. The nature of the terminal carbonyl linkage (ester or amide) and the length or type of the alkyl chain bridging the two carbonyl functions have little effect on the activity. One of the active compounds, N-(4- methoxy-benzoyl)-N'-[3-methylfuroxanyl-4-carbonyl)piperazine (17i) was tested for hypotensive effects on anaesthetized rats at 1.5 mg/kg, and found to demonstrate a gradual and sustained hypotensive effect. The results suggest that the furoxannicorandil derivatives are a useful lead in the design of NO- donor compounds for hypertension.
Oxazolines. 3. Regioselective Synthesis of 2-(Monosubstituted phenyl) and/or Unsymmetrically 2-(Disubstituted phenyl) 2-Oxazolines by Cross-Coupling Grignard Reagents to (Haloaryl)-2-oxazolines
Pridgen, Lendon N.
, p. 4319 - 4323 (2007/10/02)
2-(Monosubstituted phenyl) 2-oxazoline 5 (R = H) and unsymmetrically 2-(disubstituted phenyl) 2-oxazolines 5 have been prepared by cross-coupling alkyl and aryl Grignard reagents to 2-(mono- and dihalogenated phenyl) 2-oxazolines 2 and 3 (X = halogen), re
