63864-53-9Relevant academic research and scientific papers
Decarbonylative Suzuki-Miyaura Cross-Coupling of Aroyl Chlorides
Zhou, Tongliang,Xie, Pei-Pei,Ji, Chong-Lei,Hong, Xin,Szostak, Michal
, p. 6434 - 6440 (2020/09/02)
Herein, we report a catalyst system for Pd-catalyzed decarbonylative Suzuki-Miyaura cross-coupling of aroyl chlorides with boronic acids to furnish biaryls. This strategy is suitable for a broad range of common aroyl chlorides and boronic acids. The synthetic utility is highlighted in the direct late-stage functionalization of pharmaceuticals and natural products capitalizing on the presence of carboxylic acid moiety. Extensive mechanistic and DFT studies provide key insight into the reaction mechanism and high decarbonylative cross-coupling selectivity.
Oxidative addition of Sn-C bonds on palladium(0): Identification of palladium-stannyl species and a facile synthetic route to diphosphinostannylene- palladium complexes
Cabon, Yves,Reboule, Irena,Lutz, Martin,Klein Gebbink, Robertus J. M.,Deelman, Berth-Jan
, p. 5904 - 5911 (2011/01/03)
Methyl-, phenyl-, and n-butyltin trichloride RSnCl3 (R = Me, Ph, nBu) react selectivily with palladium(0)-phosphine precursors through the unprecedented oxidative addition of the Sn-C bond. With [Pd(2-PyPPh2)3] (2-PyPPh2 = 2-pyridyldiphenylphoshine), the reaction cleanly leads to stable cationic dichlorostannylene palladium complexes of the general formula trans-[PdR(SnCl2(2-PyPPh2)2)][X] (X = Cl, R = Me ([5]Cl), R = Ph ([6]Cl), R = nBu ([11]Cl); X = RSnCl4, R = Me ([5][MeSnCl4]), R = Ph ([6][PhSnCl4]), R = nBu ([11][nBuSnCl4])). The SnCl 2(2-PyPPh2)2 fragment, formed by intramolecular coordination of the pyridyl groups to the dichlorostannylene moiety, can be considered as a self-assembled pincer-type ligand with a remarkable ability to suppress β-H elimination in its Pd-alkyl derivatives: [11][ nBuSnCl4], containing a Pd-nBu moiety, was found to be stable up to 70 °C. Oxidative addition of SnCl4 on [Pd(2-PyPPh2)3] resulted in trans-[PdCl(SnCl 2(2-PyPPh2)2)]Cl ([7]Cl) and trans-[PdCl(SnCl3(2-PyPPh2)2)] (8). The molecular structure of 8 was determined by single-crystal X-ray crystallography, indicating that the Sn atom of the trichlorostannyl function has an octahedral coordination geometry. In contrast, oxidative addition of the Sn-C bond of RSnCl3 on [Pd(PPh3)4] resulted in palladium trichlorostannyl complexes that were not stable toward cis-trans isomerization, (partial) elimination of SnCl2 (R = Me, Ph), or β-H elimination (R = nBu). The resulting mixtures of palladium alkyl and palladium hydride species were analyzed by multinuclear NMR, resulting in the identification of novel cis-[PdMe(SnCl3)(PPh3) 2] (cis-4), trans-[PdMe(SnCl3)(PPh3) 2] (trans-4), and cis-[PdH(SnCl3)(PPh3) 2] (cis-10) along with previously observed trans-[PdPh(Cl)(PPh 3)2] (1), trans-[PdMe(Cl)(PPh3)2] (3), trans-[PdH(SnCl3)(PPh3)2] (trans-10), and trans-[PdH(Cl)(PPh3)2] (9).
Oxidative addition step in reactions involving palladium activation of carbon-halogen and carbon-oxygen bonds
Shmidt,Smirnov
, p. 495 - 501 (2008/10/09)
Different modifications of the Heck reaction involving the activation of carbon-halogen and carbon-oxygen bonds by palladium (styrene phenylation with iodobenzene or benzoic anhydride and iodobenzene carbonylation, reductive coupling, and reduction) are studied by in situ 31P NMR spectroscopy. The catalytic cycles of the reactions include oxidative addition to Pd(0) formed in situ. The product composition in this step depends strongly on the composition of the reaction mixture, which is related to PhX conversion in the main catalytic process and with the nature of the catalyst precursor. A new hypothesis as to the mechanism of the catalytic cycle in alkene arylation in the presence of phosphine ligands is suggested. This hypothesis is consistent with NMR monitoring data and with the value of the kinetic isotope effect.
Tetraarylphosphonium halides as arylating reagents in Pd-catalyzed heck and cross-coupling reactions
Hwang, Lee Kyoung,Na, Youngim,Lee, Junseong,Do, Youngkyu,Chang, Sukbok
, p. 6166 - 6169 (2007/10/03)
(Chemical Equation Presented) Highly efficient: Tetraarylphosphonium halides, Ar4P+X-, as arylating reagents efficiently deliver an aryl group in Pd-catalyzed reactions with olefins, organoboron compounds, and terminal alkynes (see scheme).
Reactions of free radicals with η3-allylpalladium(II) complexes: Phenyl and trityl radicals
Reid, Simon J.,Baird, Michael C.
, p. 3975 - 3980 (2007/10/03)
The compounds (η3-allyl)PdCl(PPh3) and [(η3-allyl)Pd(PPh3)2]Cl react with phenyl and trityl radicals generated from the thermal decomposition of phenylazotriphenylmethane (PhN=NCPh3, PAT) in benzene at 60°C. The products are the palladium phenyl compounds, [PdPhCl(PPh3)]2 and trans-PdPhCl(PPh3)2, respectively, and 4,4,4-triphenyl-1-butene, the latter being the result of coupling of the trityl radical with the allyl ligands. In contrast, [(η3-allyl)PdCl]2 reacts with phenyl and trityl radicals under the same conditions to form palladium metal, trityl chloride and 3-phenylpropene, which is subsequently catalytically isomerized to 1-phenylpropene. These disparate results are interpreted in all cases in terms of initial attack by phenyl radicals on the palladium(II) to give phenyl-palladium(III) intermediates, and it is the secondary reactions, influenced by the presence or absence of coordinated PPh3 ligands, which provide variety in the products. The reaction of [(4-methoxy-1,3-η3-cyclohexenyl)PdCl]2 gives a mixture of trans-3-methoxy-6-phenylcyclohexene and trans-4-methoxy-3-phenylcyclohexene, consistent with initial formation of a phenyl-palladium(III) intermediate followed by phenyl migration to the η3-cyclohexenyl ligand (reductive elimination).
Substitution reactions of trans-[PdXPh(SbPh3)2J (X=Cl or Br) with nitrogen, phosphines and arsenic donor ligands. Crystal structures of trans-[PdClPh(PPh3)2], [PdClPh(bipy)], [PdClPh(dppm)]2, and [PdB
Mentes, Ayfer,Kemmitt, Raymond D.W.,Fawcett, John,Russeli, David R.
, p. 1141 - 1145 (2008/10/08)
Exchange reactions of trans-[PdXPh(SbPh3)2] (1) (X=Cl or Br) with ligands L in refluxing dichloromethane give the palladium phenyl complexes [PdXPhL2] (X=Cl, L=PPh3, AsPh3, L2=2,2′-bipyridi
The trans influence of F, Cl, Br and I ligands in a series of square-planar Pd(II) complexes. Relative affinities of halide anions for the metal centre in trans-[(Ph3P)2Pd(Ph)X]
Flemming, Jeffrey P.,Pilon, Mark C.,Borbulevitch, Oleg Ya.,Antipin, Mikhail Yu.,Grushin, Vladimir V.
, p. 87 - 98 (2008/10/08)
Single crystal X-ray diffraction studies of trans-[(Ph3P)2Pd(Ph)X] (X = F (1), Cl (2), Br (3), and I (4)) were carried out. The four structures split in two isostructural and isomorphous groups, namely orthorhombic for 1 and 2 (space group Pbca, Z = 8) and triclinic for 3 and 4 (space group P-1, Z=2). According to the Pd-C bond length, the trans influence of X within these pairs follows the trend Cl > F and I > Br. However, the trans influence of Cl is slightly stronger than that of Br. Both structural and 13C NMR studies revealed that electron-donating effects of (Ph3P)2PdX increase along the series X = I - for the Pd centre in [(Ph3P)2Pd(Ph)]+ were studied by 31P NMR in rigorously anhydrous CH2Cl2 solutions, and equilibrium constants and ΔG values were obtained for all possible combinations. The sequence F- > Cl- > Br- > I- is characteristic of halide preference for the Pd complexes. Dissolving 1 and PPN Cl in dry CH2Cl2 resulted in the release of 'naked' F- which fluorinated the solvent smoothly to give a mixture of CH2ClF and CH2F2 in high yield. When chloroform was used instead of CH2Cl2, dichlorocarbene was generated slowly, forming the corresponding cyclopropane in the presence of styrene. All observations were rationalized successfully in terms of the filled/filled effect and push/pull interactions.
Preparation of chloride-bridged organopalladium(II) dimers and their role in the carbonylation of trans-[PdClR1(PR3)2]
Anderson, Gordon K.
, p. 665 - 668 (2008/10/08)
Complexes of the type [Pd2(μ-Cl)2R2L2] (R = Ph, C6H4Me-p, or CH2Ph; L = PPh3, PMePh2, or PBu3) are prepared by the reaction of R2Hg with [Pd2(μ-Cl)2Cl2L2] in benzene and have been characterized by elemental analysis and NMR spectroscopy. Reaction with L gives the corresponding bis(phosphine)palladium complex, while treatment with CO yields [Pd2(μ-Cl)2(COR)2L2]. Carbonylation of trans- [PdClRL2] or bridge cleavage of [Pd2(μ-Cl)2(COR)2L2] with L produces trans-[PdCl(COR)L2]. The rates of these processes are considered, and the intermediacy of the dimeric complexes in the carbonylation of trans-[PdClRL2] is discussed.
