N‑Heterocyclic-Carbene Complexes Readily Prepared from Di-μ-hydroxopalladacycles Catalyze the Suzuki Arylation of 9‑Bromophenanthrene

New cyclometalated palladium complexes of general formula [Pd­(Bmim)­(X)­(C^∧N)] have been synthesized by a novel reaction route involving di-μ-hydroxo-palladacycles [{Pd­(μ-OH)­(C^∧N)}₂] (C^∧N = 2-benzoylpyridine (Bzpy), <b>I</b>, previously unreported, or C^∧N = 2-phenylpyridine (Phpy), <b>II</b>)] and 1,3-butylmethyl­imidazolium salts [HBmim]­X (X: Cl, Br, I, or saccharinate (Sacc); <b>a</b>, <b>b</b>, <b>c</b>, or <b>d</b> complexes, respectively). This simple acid–base reaction could not be achieved under identical conditions when corresponding di-μ-acetate complexes were used as starting materials. An alternative pathway to NHC/imidate complexes has also been explored by reacting <b>IIb</b> with [Ag­(Phthal)­(SMe₂)]₂ (Phthal = phthalimidate, <b>e</b>) to obtain [Pd­(Bmim)­(Phthal)­(Phpy)], <b>IIe</b>. Structural characterization by X-ray diffraction of complexes <b>Id</b>, <b>IIb</b>, <b>IId</b>, and <b>IIe</b> has confirmed the proposed formulas. The mononuclear complexes have shown to catalyze the scalable Suzuki–Miyaura cross-coupling of 9-bromophenanthrene with a wide scope of aryl boronic acids, irrespective of their electronic properties and at a very low catalyst concentration of 0.01%

N‑Heterocyclic-Carbene Complexes Readily Prepared from Di-μ-hydroxopalladacycles Catalyze the Suzuki Arylation of 9‑Bromophenanthrene

New cyclometalated palladium complexes of general formula [Pd­(Bmim)­(X)­(C^∧N)] have been synthesized by a novel reaction route involving di-μ-hydroxo-palladacycles [{Pd­(μ-OH)­(C^∧N)}₂] (C^∧N = 2-benzoylpyridine (Bzpy), <b>I</b>, previously unreported, or C^∧N = 2-phenylpyridine (Phpy), <b>II</b>)] and 1,3-butylmethyl­imidazolium salts [HBmim]­X (X: Cl, Br, I, or saccharinate (Sacc); <b>a</b>, <b>b</b>, <b>c</b>, or <b>d</b> complexes, respectively). This simple acid–base reaction could not be achieved under identical conditions when corresponding di-μ-acetate complexes were used as starting materials. An alternative pathway to NHC/imidate complexes has also been explored by reacting <b>IIb</b> with [Ag­(Phthal)­(SMe₂)]₂ (Phthal = phthalimidate, <b>e</b>) to obtain [Pd­(Bmim)­(Phthal)­(Phpy)], <b>IIe</b>. Structural characterization by X-ray diffraction of complexes <b>Id</b>, <b>IIb</b>, <b>IId</b>, and <b>IIe</b> has confirmed the proposed formulas. The mononuclear complexes have shown to catalyze the scalable Suzuki–Miyaura cross-coupling of 9-bromophenanthrene with a wide scope of aryl boronic acids, irrespective of their electronic properties and at a very low catalyst concentration of 0.01%

Water-Soluble Pd–Imidate Complexes: Broadly Applicable Catalysts for the Synthesis of Chemically Modified Nucleosides via Pd-Catalyzed Cross-Coupling

A broadly applicable catalyst system consisting of water-soluble Pd–imidate complexes has been enployed for the Suzuki–Miyaura cross-coupling of four different nucleosides in water under mild conditions. The efficient nature of the catalyst system also allowed its application in developing a microwave-assisted protocol with the purpose of expediting the catalytic reaction. Preliminary mechanistic studies, assisted by catalyst poison tests and stoichiometric tests performed using an electrospray ionization spectrometer, revealed the possible presence of a homotopic catalyst system