51560-55-5Relevant articles and documents
Cross-Coupling between Hydrazine and Aryl Halides with Hydroxide Base at Low Loadings of Palladium by Rate-Determining Deprotonation of Bound Hydrazine
Borate, Kailaskumar,Choi, Kyoungmin,Goetz, Roland,Hartwig, John F.,Shinde, Harish,Wang, Justin Y.,Zuend, Stephan J.
, p. 399 - 408 (2020/10/29)
Reported here is the Pd-catalyzed C–N coupling of hydrazine with (hetero)aryl chlorides and bromides to form aryl hydrazines with catalyst loadings as low as 100 ppm of Pd and KOH as base. Mechanistic studies revealed two catalyst resting states: an arylpalladium(II) hydroxide and arylpalladium(II) chloride. These compounds are present in two interconnected catalytic cycles and react with hydrazine and base or hydrazine alone to give the product. The selectivity of the hydroxide complex with hydrazine to form aryl over diaryl hydrazine was lower than that of the chloride complex, as well as the catalytic reaction. In contrast, the selectivity of the chloride complex closely matched that of the catalytic reaction, indicating that the aryl hydrazine is derived from this complex. Kinetic studies showed that the coupling process occurs by rate-limiting deprotonation of a hydrazine-bound arylpalladium(II) chloride complex to give an arylpalladium(II) hydrazido complex.
Oxone-DMSO Triggered Methylene Insertion and C(sp2)-C(sp3)-H-C(sp2) Bond Formation to Access Functional Bis-Heterocycles
Bharatam, Prasad V.,Dubey, Gurudutt,Hussain, Yaseen,Kour, Jaspreet,Sahoo, Subash C.,Sawant, Sanghapal D.,Venkateswarlu, Vunnam,Verma, Praveen K.
supporting information, p. 4951 - 4962 (2020/05/08)
Metal-free insertion of a methylene group was achieved for the construction of a new C(sp2)-C(sp3)-H-C(sp2) bond in order to prepare novel bis-heterocyclic scaffolds. The complete mechanistic investigations included experimental study and DFT calculations, and various symmetric and unsymmetric bis-pyrazoles as well as other pyrazole-based bis-heterocyclic molecules were prepared in moderate to high yields. Further modification of the bridged methylene group in the unsymmetric pyrazoles generated a chiral center to extend the scope of this method.
1-Aryl-3,5-dimethylpyrazolium based tunable protic ionic liquids (TPILs)
?zdemir, Melek Canbulat,?zgün, Beytiye,Aktan, Ebru
, p. 564 - 572 (2019/01/05)
A series of new 1-aryl-3,5-dimethylpyrazolium based tunable protic ionic liquids/salts ([PhRHpz][X], R: –H, –Cl, –Br, –CH3, –OCH3, X: chloride [Cl?] and tetrafluoroborate [BF4 ?]) have been synthesized through acid-base neutralization reactions between 1-aryl-3,5-dimethyl-1H-pyrazoles and the corresponding inorganic acids. The chemical structure of the salts was confirmed by FTIR, 1H NMR, 13C NMR, elemental analysis, and 19F NMR (3a-3e) and the crystal structure of the two salts (2a and 3d) was also elucidated by X-ray analysis of single crystals. Melting points and thermal decomposition temperatures of TPILs (2e and 3b) were determined. The geometries of the cations, anions and ionic salts were optimized, and their molecular electrostatic potentials (MEPs) were assessed by using density functional theory methods (B3LYP and M06-2X). The electrochemical window of the salts was determined both experimentally and theoretically. The correlation coefficient values were also calculated by using theoretical and experimental EW values of the salts.
