Synthesis and characterization of [4‐{(CH2O)2CH}C6H4]2Hg, [4‐(O=CH)C6H4]2Hg and [(E)‐4‐(RN=CH)C6H4]2Hg (R = 2′‐py, 4′‐py, 2′‐pyCH2, 4′‐pyCH2)

The reaction of 4‐[(CH2O)2CH]C6H4Br (1) with n‐BuLi, followed by addition of HgCl2 to the in situ formed organolithium derivative, affords [4‐{(CH2O)2CH}C6H4]2Hg (2). Deprotection of the formyl groups of 2 in presence of p‐TsOH (p‐Ts = 4‐MeC6H4SO3) leads to [4‐(O=CH)C6H4]2Hg (3). Condensation reactions of 3 with 2‐aminopyridine (2‐pyNH2), 4‐aminopyridine (4‐pyNH2), 2‐aminomethylpyridine (2‐pyCH2NH2), and 4‐aminomethylpyridine (4‐pyCH2NH2), in CH2Cl2, affords the novel diorganomercury(II) compounds of type [(E)‐4‐(RN=C)C6H4]2Hg [R = 2′‐py (4), 4′‐py (5), 2'‐pyCH2‐ (6), 4′‐pyCH2 (7)]. Compounds 2 and 3 were useful precursors for the preparation of the corresponding homocoupling products [4‐{(CH2O)2CH}C6H4]2 (8) and [4‐(O=CH)C6H4]2 (9) in presence of catalytic amounts of palladium(II) acetate. Compounds 2–9 were characterized by multinuclear magnetic resonance (NMR) (1H, 13C{1H}, and 199Hg{1H}, when appropriate) and infrared (IR) spectroscopy and by mass spectrometry. The molecular structures of 3, 5, 6, 8, and 9 were determined by single‐crystal X‐ray diffraction. Highlights: A quick, easy, and economic synthesis was optimized for bis(4‐formylphenyl)mercury(II).Syntheses of novel homoleptic diorganomercury(II) compounds with imine functional groups were optimized to give good to excellent yields in mild conditions with easy workup.All diorganomercury(II) compounds were characterized by multinuclear (1H, 13C{1H}, and 199Hg{1H} NMR) and IR spectroscopy as well as mass spectrometry and, for three compounds with imine functional groups, the molecular structure was determined by single‐crystal X‐ray diffraction.The use of diorganomercury(II) compounds as starting materials for homocoupling reactions, in presence of catalytic amounts of palladium(II) acetate, was investigated. [ABSTRACT FROM AUTHOR]