1137-79-7Relevant articles and documents
Photochemistry and photophysics of triarylmethane dye leuconitriles
Jarikov,Neckers
, p. 659 - 671 (2001)
The photochemical reactions of crystal violet leuconitrile (CVCN) were investigated by the means of product analysis and trapping experiments, laser flash and steady-state photolysis, and steady-state fluorescence. The influence of oxygen on the reaction was examined in detail. The photochemistry of malachite green leuconitrile (MGCN), basic fuchsin leuconitrile (BFCN), and crystal violet leucomethyl (CVMe) and leucobenzyl (CVBn), as well as triphenylacetonitrile, was studied. The results suggest ionization occurs from S1, while the di-π-methane reaction is the photochemical route from T1.
Characterizing ionic liquids as reaction media through a chemical probe
Dichiarante, Valentina,Betti, Cecilia,Fagnoni, Maurizio,Maia, Angelamaria,Landini, Dario,Albini, Angelo
, p. 1834 - 1841 (2007)
The triplet N,N-dimethylaminophenyl cation, a highly reactive but chemospecific electrophile, has been used as a probe for characterizing the properties of reaction media for a series of imidazolium ILs. With the N-hexyl-N-methyl imidazolium derivatives (not with the W-butyl analogues), hydrogen transfer leading to the aniline was the main process. Trapping by iodide occurred with an inverse dependence on viscosity. Trapping by it nucleophiles exhibited a more complex behavior. This was explained by the effect of both the bulk viscosity and the structure of the IL cation on both steps of the reaction, namely, initial electrophilic attack and ensuing cation elimination or nucleophile addition. However, with an excellent nucleophile, such as thiophene, or when the latter step was intramolecular, as with 4-pentenol, the difference was obliterated and trapping became uniform. Incorporation of the probe into the IL cation (through insertion into the C-H bond a to the imidazolium ring) was demonstrated, while no addition to the anion tested (including bis(trifluoromethanesulfonimide)) took place.
Cobalt-catalyzed cross-coupling reactions of aryl- And alkylaluminum derivatives with (hetero)aryl and alkyl bromides
Dilauro, Giuseppe,Messa, Francesco,Bona, Fabio,Perrone, Serena,Salomone, Antonio
supporting information, p. 10564 - 10567 (2021/10/19)
A simple cobalt complex, such as Co(phen)Cl2, turned out to be a highly efficient and cheap precatalyst for a host of cross-coupling reactions involving aromatic and aliphatic organoaluminum reagents with aryl, heteroaryl and alkyl bromides. New C(sp2)-C(sp2) and C(sp2)-C(sp3) bonds were formed in good to excellent yields and with high chemoselectivity, under mild reaction conditions.
Palladium(II) complexes of Y,C,Y-chelated phosphines: Synthesis, structure, and catalytic activity in Suzuki-Miyaura reaction
Reznicek, Tomas,Dostal, Libor,Ruzicka, Ales,Kulhanek, Jiri,Bures, Filip,Jambor, Roman
experimental part, p. 173 - 179 (2012/04/23)
The phosphines L1PPh2 (1) and L2PPh 2 (2) containing different Y,C,Y-chelating ligands, L1 = 2,6-(tBuOCH2)2C6H3 - and L2 = 2,6-(Me2NCH2) 2C6H3-, were treated with PdCl 2 and di-Aμ-chloro-bis[2-[(N,N-dimethylamino)methyl]phenyl- C,N]-dipalladium(II) and yielded complexes trans-{[2,6-(tBuOCH 2)2C6H3]PPh2} 2PdCl2 (3), {[2,6-(Me2NCH2) 2C6H3]PPh2} PdCl2 (4), {[2,6-(tBuOCH2)2C6H 3]PPh2}Pd(Cl)[2-(Me2NCH2)C 6H4] (5) and {[2,6-(Me2NCH2) 2C6H3]PPh2}Pd(Cl)[2-(Me 2NCH2)C6H4] (6) as the result of different ability of starting phosphines 1 and 2 to complex PdCl2. Compounds 3-6 were characterized by 1H, 13C, 31P NMR spectroscopy and ESI-MS. The molecular structures of 3,4 and 6 were also determined by X-ray diffraction analysis. The catalytic activity of complexes 3-6 was evaluated in the Suzuki-Miyaura cross-coupling reaction.
Using phenyl cations as probes for establishing electrophilicity - Nucleophilicity relations
Dichiarante, Valentina,Fagnoni, Maurizio,Albini, Angelo
, p. 1282 - 1289 (2008/09/16)
(Chemical Equation Presented) N,N-Dimethyl-4-aminophenyl cation is used as an electrophilic probe for determining the relative reactivity of nucleophiles. The singlet state (11) of this cation is completely unselective (reaction rates with benzene, MeCN, and trifluoroethanol within a factor of 5). The corresponding triplet (31) does not react with alcohols and MeCN. The rates of reaction of the latter intermediate with 23 π, σ, and n nucleophiles are measured by competition experiments and found to vary over only 2 orders of magnitude over a range of 22 units of the nucleophilicity parameter N introduced by Mayr. As far as one can judge with the considerable scatter of the data, fitting the data of both amines and π nucleophiles is possible only by using a modified Mayr's equation: log k = s(E + eN) with e = 0.33. The reduced dependence on N is explained by the fact that in the case of diradicalic triplet 31 interaction with the nucleophile involves a half-filled (σ) orbital, which is empty in singlet 11. It is suggested that Mayr's equation can be extended to quite diverse reactions, but a scaling factor of e 1 may have to be introduced in some cases, according to the electronic structure of the electrophilic probe used.
