17333-79-8Relevant articles and documents
Dba-free palladium intermediates of the Heck-Matsuda reaction
MacHado, Angelo H. L.,Milagre, Humberto M. S.,Eberlin, Livia S.,Sabino, Adao A.,Correia, Carlos Roque D.,Eberlin, Marcos N.
, p. 3277 - 3281 (2013)
The dba-free Heck-Matsuda reaction was investigated via direct ESI-MS(/MS) monitoring. Palladium species involved in the reduction of Pd(ii) during a Wacker type reaction and several dba-free arylpalladium transient complexes were detected and characterized. Based on these findings, a more comprehensible catalytic cycle for this pivotal reaction is suggested.
Inhibition of Acid-induced decomposition of diphenyltriazenes by complexation with cyclodextrins
Xu, Tingting,Asadi, Atefeh Vaez-Zadeh,Barra, Monica
supporting information; experimental part, p. 567 - 574 (2011/04/26)
Acid-promotedN Nbond cleavage in 1,3-diphenyltriazenes (X-Ph-N=N-NH-Ph-X X = H, 4-OCH3), leading to formation of diazonium ions and anilines, is strongly inhibited in aqueous solutions in the presence of cyclodextrins (CDs). The inhibition is ascribed to the formation of inclusion complexes that render the guest diphenyltriazene significantly less basic as a result of the less polar nature of the CD cavity (amicrosolvent effect). Association equilibrium constants for 1:1 host-guest complexes increase in the order α-CD 3 being larger than those for X = H. In the case of α-CD, formation of 2:1 host-guest complexes is also involved.
Pulsed Ultraviolet Laser Photolysis of Substituted Phenyl Diazosulphonates at 248 nm
Nomayo, M.,Wokaun, A.
, p. 1495 - 1503 (2007/10/02)
The photochemical decomposition of aqueous phenyl diazosulphonate solutions by KrF excimer laser pulses at 248 nm is investigated.The present study complements earlier investigations (Franzke et al. 1991, 1992) of the photochemistry of this class of compounds induced by irradiation at 308 nm (XeCl excimer laser), and in the 370-390 nm wavelength range (dye laser pulses).From the comparison, conclusions with regard to the wavelength dependent photolysis pathway are drawn.Phenyl diazosulphonates carrying methoxy- or ester-type substituents at the aromatic ring are observed to decompose in a two-step-reaction in aqueous solution: Photolysis proceeds via the phenyl diazonium ion as an intermediate, to yield the corresponding phenol as product.In contrast, the photolysis of 3-vinyl-phenyl diazosulphonate in aqueous solution at 248 nm results in a complex reaction involving via more than one intermediate.UV spectra recorded during photolysis show that products characterized by an absorption maximum at 272 nm are formed; these spectra are identical with those of final products from 308 nm photolysis, which are identified as 3-hydroxyethyl-phenols. - The photolysis pathway of 4-hydroxy-phenyl-diazosulphonate is found to proceed via the diazoquinone, instead of a diazonium ion.As a consequence of the high energy of 248 nm photons, the mentioned substituted phenols are not the final products of the photochemical reaction.These molecules are further decomposed by absorbing 248 nm photons; the quantum efficiency of these secondary photochemical reactions is lower by one to two orders of magnitude, as compared to the primary photolysis of the parent compounds. - Keywords: Light, Absorption / Materials Properties, Diazo Sulphonates / Photochemistry / Radicals / Spectroscopy, Ultraviolet
