Syntheses of Ortho-Mercurated and -Palladated (η⁶-Arene)tricarbonylchromium Complexes

Abstract

The selective ortho mercuration of tricarbonylchromium derivatives of 2-phenylpyridine, N,N-dimethylbenzylamine, (1S)-1-(dimethylamino)-1-phenylethane, and 2-phenyl-2-oxazoline by Hg(OAc) 2 is reported. The mercurations of the latter (η 6 -arene)Cr(CO) 3 complexes bearing an endogenous ligand have been carried out in soft conditions with yields ranging from 13 to 83%. The optically active complex of (1S)-1-(dimethylamino)-1-phenylethane was stereoselectively orthomercurated. The conversion of the chloromercurated complexes, e.g. (η 6 -Ar-HgX)Cr(CO) 3 , into the corresponding homoleptic trinuclear [(η 6 -Ar)Cr(CO) 3 ] 2 Hg complexes was readily carried out by reaction with Me 4 NCl in boiling acetone. In almost all cases, the so-called symmetrization reaction afforded a mixture of two diastereomers, except for the derivative of (1S)-1-(dimethylamino)-1-phenylethane, which afforded a unique "symmetrized" product. This result suggests that the "symmetrization" reaction occurred with retention of the configuration of the mercury-bound ipso carbon atom. The trimetallic and bimetallic mercurated (η 6 -arene)Cr(CO) 3 complexes were readily converted into cyclopalladated binuclear complexes upon transmetalation with Pd(II) salts. The structures of two orthomercurated compounds and two ortho-palladated complexes are reported.

Effect of Enhanced Electron Withdrawal on the Cohesion of Cr‐Pd Hemichelates

“…IR spectra were acquired with a FT‐IR Bruker alpha spectrometer using an ATR solid‐state sample cell. Complex 1b as well as palladacycles 2 and 3 were synthesized according to published procedures , …”

“…Complex 1b as well as palladacycles 2 and 3 were synthesized according to published procedures. [22,23] Standard Procedure for the Synthesis of 4b and 5b…”

Crystal structure of {2,6-bis[(dimethylamino)methyl]phenyl-κ3N,C1,N′}(bromido/chlorido)mercury(II)

“…Organomercury(II) derivatives have been used successfully to obtain the desired organometallic compounds of transition metals, as well as main group metals otherwise inaccessible by classical Grignard and/or lithiation reactions (Bonnardel et al, 1996;Gul & Nelson, 1999a,b;Berger et al, 2001Berger et al, , 2003Zhang et al, 2005;Djukic et al, 2006). Although the toxicity of mercury compounds should always be taken into account, there are important advantages, e.g.…”

Reactivity of Unsaturated 5(4H)-Oxazolones with Hg(II) Acetate: Synthesis of Methyl N-Benzoylamino-3-arylacrylates

“…Curiously the electron activated substrate 1e [32] could not be hydrolyzed in the above conditions even if the reaction time was increased to 24 hours. In addition, even it is widely accepted that the mercuriation occurs mainly through an electrophilic substitution S E Ar pathway [33] no metallating product was detected after workup when activated substrate 1e was employed.…”