The use of control experiments as the sole route to correct the mechanistic interpretation of mercury poisoning test results: The case of P,C-palladacycle-catalysed reactions

摘要: Abstract In the study of metallic mercury interaction with cyclopalladated derivatives tris-ortho-tolylphosphine [{(κ2P,C-L)Pd(μ-X)}2], redox-transmetallation palladacycles by formation P,C-chelated benzylmercurials [(κ2P,C-L)HgX] was revealed at moderate temperature in presence excess Hg(0). contrast, mercury(0) testing Suzuki reaction same chloride P,C-precatalyst gave a negative result, even higher and greater The structures these mercurials have been convincingly confirmed spectrally (1Н, 13С, 31Р 199Hg NMR), via X-ray diffraction DFT calculations for mercurial. Our results analysis known data on diagnostics catalytic systems classical anomalous P,C-precatalysts enable us to assume that intact state palladacycle is present key anionic intermediate [(κ2P,C-L)Pd0]– cycles Heck reactions lower reactivity Hg(0) palladium(0) complexes comparison palladium(II) analogues.