ESI-MS Studies on the Mechanism of Pd(0)-Catalyzed Three-Component Tandem Double Addition-Cyclization Reaction

Abstract

Four cationic palladium intermediates have been characterized by the high-resolution ESI-FTMS technology, on the basis of which a mechanism was proposed for the Pd0-catalyzed three-component tandem double addition cyclization of organic halides, 2-(2,3-allenyl)malonates, and imines.

The application of electrospray ionization mass spectrometry to homogeneous catalysis

“…Peaks were observed corresponding to allyl-type intermediates such as Some less common Pd-catalyzed bond-forming reactions have been investigated as well, including tellurium-carbon bond formation (ionized by loss of halide) [14], intramolecular nitrogen-carbon bond formation (ionized by association of H + or Na + ) [67], and the formation of two new carbon-oxygen bonds in the hydroxyalkoxylation of 2-allylphenols (ionized by loss of H + in the negative-ion mode, and loss of an anionic ligand or association of Na + in positive-ion mode) [68]. A study by Guo et al determined the mechanism of a palladium-catalyzed three-component cyclization reaction (the formation of cispyrolidine derivatives from imine, iodobenzene and 2-(2,3-allenyl)malonate) [69]. Three key cationic M a n u s c r i p t 23 organopalladium species that had lost halide ligands were detected by ESI-FTMS.…”

Palladium Intermediates in Solution

“…Tin-containing species I61 was also observed and assigned as another transmetalation product. At m/z ¼ 657, species I62 might proceed from neutral species [ArPd Apart from the methodological synthetic study, the authors conducted a mechanistic study of the process using the ESI-MS technique [43]. The particular reaction studied is shown in Scheme 7.22.…”

Electrospray mass spectrometric studies of nickel(II)-thiosemicarbazones complexes: Intra-complex proton transfer in the gas phase ligand exchange reactions

“…The application of electrospray ionization mass spectrometry (ESI-MS) for investigation of metal complexes and metal-ligand interactions is well recognized [13][14][15][16][17][18][19]. The gas phase chemistry of a well-defined complex ion can be investigated by taking advantage of the multistage mass spectrometry (MS n ) capabilities of ion trap mass spectrometer [15,18], unencumbered by cluster effects, nickel(II) complex was prepared by dissolving NiCl 2 and M in a selected solvent and diluting it to a concentration of about 10 ppm.…”