Aurelia Arcas

Synthesis of a Palladium(IV) Complex by Oxidative Addition of an Aryl Halide to Palladium(II) and Its Use as Precatalyst in a CC Coupling Reaction

and the two isomers of complex 2.[*] Prof. Dr. J. Vicente, Prof. Dr. A. Arcas, M. Sc. F. Juli-HernndezGrupo de Qumica OrganometlicaDepartamento de Qumica Inorgnica, Facultad de QumicaUniversidad de Murcia, Aptdo. 4021, 30071 Murcia (Spain)E-mail: jvs1@um.esHomepage: http://www.um.es/gqo/Dr. D. BautistaSAI, Universidad de Murcia, Aptdo. 4021, 30071 Murcia (Spain)Supporting information for this article is available on the WWWunder http://dx.doi.org/10.1002/anie.201102214.

Quantitative synthesis and full characterization of the first isolated and stable pincer palladium(IV) complexes. Quantitative and regioselective synthesis of the C–X (X = Cl, Br) reductive elimination products

The pincer complexes [Pd(O(1),N(1),C(1)-L)X], where X = Cl, Br and L is the monoanionic ligand resulting from deprotonation of the acetyl methyl group of the monoketal of 2,6-diacetylpyridine (dap), react with excess of Cl(2) or Br(2) affording, quantitatively, the Pd(IV) complexes [Pd(O(1),N(1),C(1)-L)X(3)], which have been characterized by X-ray diffraction, and their decomposition that quantitatively affords the reductive elimination products L-X has been studied.

A new way of synthesising diarylgold(III) complexes using organomercury compounds

Abstract Treatment of [Me 4 N][AuCl 4 ] with di-organomercury derivatives R 2 Hg in which R is an ortho -nitroaryl group (R = o -O 2 NC 6 H 4 or 2-CH 3 , 6-O 2 NC 6 H 3 ) gives anionic gold(III) complexes of the type cis -Me 4 N[AuR 2 Cl 2 ]. These react with (a) KCN, to give the anionic complexes cis -Me 4 N[AuR 2 (CN) 2 ], (b) neutral monodentate ligands (L) to give the neutral complexes cis -[AuR 2 Cl(L)] (L = PPh 3 , PCy 3 , py), and (c) 1,2-bis(diphenylphosphino)ethane (dpe) in the presence of NaClO 4 to give the cationic complexes cis -[AuR 2 (dpe)]ClO 4 . The complexes are thought to be the first transition metal complexes containing ortho -nitroaryl ligands.

Gold(I) and gold(III) ortho-nitrophenyl complexes. Crystal and molecular structure of ortho-nitrophenyltriphenylarsinegold(I)

Abstract The reaction between [Au(o-C6H4NO2)Cl]− and tetrahydrothiophene (tht) in the presence of NaClO4 give a solution (probably containing [Au(o-C6H4NO2)(tht)]) that can be used to prepare neutral [Au(o-C6H4NO2)Ln] (L = AsPh3, n = 1; L = SbPh3, n = 2; L = 1,10-phenanthroline, n = 1) or anionic [Au(o-C6H4-NO2(CN)]− complexes. Treatment of [Au(o-C6H4NO2)(PPh3)] with chlorine or PhICl2 gives trans- or cis-[Au(o-C6H4NO2)Cl2(PPh3)]. Isomerizations occur when the cis-isomer is treated with concentrated solutions of chlorine or when the trans-isomer is heated. An X-ray diffraction study of [Au(o-C6H4NO2)(AsPh3)] has revealed an almost linear coordination around the gold atom (AsAuC mean value 177(2)°). The AuO distance is too long (mean value 2.80(3) A) for intramolecular coordination.

Bispentafluorophenyl nickel(II) complexes

Abstract Solutions apparently containing Ni[C 6 F 5 ) 2 are obtained by reaction of anhydrous NiBr 2 with [C 6 - F 5 ]MgBr in THF. The addition of different ligands to these solutions gives four-coordinate nickel(II) complexes of the type (C 6 F 5 ) 2 NiL 2 [L = PEt 3 PBu 3 , PPh 3 AsPh 3 SbPh 3 , OPPh 3 OAsPh 3 , p-Dioxane]. Structural data for these compounds are obtained by visible-UV and 1R spectroscopy and magnetic susceptibility measurements.

ortho-, meta- and para-nitrophenylgold(I) complexes

Abstract Treatment of [BzPh 3 P][AuCl 2 ] with [Hg( x -C 6 H 4 NO 2 ) 2 ] ( x = o , m , or p ) gives anionic gold(I) complexes of the type [BzPh 3 P][Au(R)Cl](R = o -, m - or p -C 6 H 4 NO 2 , Bz = C 6 H 5 CH 2 ). The chloro ligand in [Au( o -C 6 H 4 NO 2 )Cl] − can be replaced by bromo or iodo ligands by use of NaBr or NaI. The anions [Au(R)Cl] − react with neutral monodentate ligands, L, to give neutral mononuclear complexes [Au(R)L] (R = o -C 6 H 4 NO 2 , L = PPh 3 , AsPh 3 ; R = m -C 6 H 4 NO 2 , L = PPh 3 ) and with 1,2-bis(diphenylphosphino)ethane (dpe) to give [Au 2 (R) 2 (dpe)] (R = o -C 6 H 4 NO 2 ). The corresponding [Au( p -C 6 H 4 NO 2 )Cl] − reacts with PPh 3 or AsPh 3 to give mixtures containing [AuClL]. The anionic ortho -nitrophenylgold(I) complex is much more stable than its meta - or para -nitrophenyl isomers. These are thought to be the first reports of nitrophenylgold(I) complexes.

Some attempts to prepare chelating nitrophenylpalladium(II) complexes. Synthesis of covalent arylpalladium(II) perchlorate complexes. Crystal and molecular structure of catena-trans- {[Pd{C6H2(NO2)3-2,4,6} (tht)2(H2O)]{ClO4}n (tht = tetrahydrothiophene)

Abstract Complexes [Pd(R)CIL 2 ] [R = C 6 H 2 (NO 2 ) 3 -2,4,6, L = tetrahydrothiophene (tht) or PPh 3 , or L 2 1,5-cyclooctadiene (COD); R = C 2 H 3 Me-2,NO 2 -6, L 2 = 1,10-phenanthroline (phen) or 2,2′-bipyridyl (bipy)l react with AgClO 4 to give the corresponding perchlorato-complexes [Pd(R)(OClO 3 )L 2 ]. Of these only some could be isolated and characterized [R = C 6 H 2 (NO 2 )3-2,4,6, L = tht ( 1 ); R = C 6 H 3 Me-2-NO 2 -6, L 2 = phen ( 2 ) or bipy ( 3 )]. These complexes, and solutions of the other non-isolated perchlorato-complexes, react with different neutral ligands to give cationic complexes [Pd(R)L 2 L′]ClO 4 [R = C 6 H 2 (NO 2 ) 3 -2,4,6, L = tht, L′ = H 2 O ( 4 ); L′= PPh 3 , L 2 = phen ( 5 ) or COD ( 6 ); R = C 6 H 3 Me-2-NO 2 -6, L′= PPh 3 , L 2 = phen ( 7 )]. The complex (PhCH 2 PPh 3 )[Pd(R)Cl 2 (dmso)] (R = C 6 H 2 (NO 2 ) 3 -2,4,6, dmso = dimethyl sulphoxide) reacts with Ag 2 (OX) (ox = oxalate) to give (PhCH 2 PPh 3 )[Pd(R)(ox)-(dmso)l ( 8 ) and (NMe 4 ) 2 [Pd,(R) 2 Cl 2 (μ-Cl) 2 ] (R = C 2 H 3 Me-2-NO 2 -6) reacts with Tl(acac) (acacH = acetylacetone) to give [Pd(R)(acac)] ( 9 ). IR studies suggest that in this complex the aryl ligand is chelating. The crystal structure of trans -[Pd{C 6 H 2 (NO 2 ) 3 -2,4,6}(tht) 2 (H 2 O)] ClO 4 shows that each perchlorate anion bridges two cations using two different oxygen atoms which gives a catena structure with a helical frame. The anion-cation interaction seems to be through hydrogen bonding with the coordinated water molecule. CC bond angles in the trinitrophenyl group support suggestions that nitro groups exert a - I inductive effect rather than a - M effect on the ring electron density.

2,4,6-Trinitrophenylgold(I) complexes. X-Ray crystal structures of [Au(SbPh3)4][Au{C6H2(NO2)3-2,4,6}2]·Et2O and [Au{C6H2(NO2)3-2,4,6}(dmphen)](dmphen = 2,9-dimethyl-1,10-phenanthroline)

The reaction of [PPh3(CH2Ph)][AuCl2] in refluxing acetone with [Hg{C6H2(NO2)3-2,4,6}2](1 : 0.55) and excess of NMe4Cl affords NMe4[HgCl3] and [PPh3(CH2Ph)][Au{C6H2(NO2)3-2,4,6}Cl](1). Complex (1) reacts with excess of both NaClO4·H2O and tetrahydrothiophene (tht) at room temperature to give [Au{C6H2(NO2)3-2,4,6}(tht)](2) which reacts with SbPh3(1 : 2) or with excess of 2,9-dimethyl-1,10-phenanthroline (dmphen) to give [Au(SbPh3)4][Au{C6H2(NO2)3-2,4,6}2](3) or [Au{C6H2(NO2)3-2,4,6}(dmphen)](4), respectively. Crystal structures were determined for complexes (3) and (4). That of (3)[space group P21/n, a= 12.320 5(18), b= 35.802(6), c= 19.759(3)A, β= 102.24(2)°, and Z= 4; R= 0.053, R′= 0.051] consists of tetrahedral [Au(SbPh3)4]+ cations (mean Au–Sb bond length 2.651 A), linear [Au{C6H2(NO2)3-2,4,6}2]– anions (Au–C 2.015 and 2.041 A), and diethyl ether of crystallization. The nitro groups display high thermal motion or disorder. The crystal structure of complex (4)[space group P21/c, a= 7.165 8(8), b= 16.976 3(18), c= 16.471 8(24)A, β= 99.80(2)°, and Z= 4; R=R′= 0.023] consists of neutral molecules with geometry intermediate between two- and three-co-ordination (Au–C 2.000, Au–N 2.136, 2.573 A; C–Au–N 168.4°). Both complexes show ipso C–C–C angles much less than the ideal 120°.

Anionic 2,4,6-trinitrophenylpalladium(II) complexes. Crystal structure of cis-[PdCl2{2,4,-C6H2(NO2)3}{S(O)Me2}]−

Abstract Treatment of [(PhCH2)PPh3]2[Pd2Cl4(μ-Cl)2] with HgR2 (R = 2,4,6-trinitrophenyl) ( 1 2 ) in refluxing acetone gives [(PhCH2)PPh3]2[Pd2R2Cl2(μ-Cl)2]-·2Me2CO (1). Reaction of 1 with an excess of NaX gives [(PhCH2)PPh3]2[Pd2R2-X2(μ-X)2][X = Br (2), I (3)]. Reactions of 1 or 2 with dimethylsulfoxide give the complexes cis-[(PhCH2)PPh3][Pd(R)X2{S(O)Me2}] (X = Cl (4) or Br (5)). An X-ray diffraction study of complex 4 has revealed a square-planar coordination around the palladium atom, with mutually cis chloro ligands and a S-bonded coordination of dimethylsulfoxide. The shortest Pd-O distances (2.911 and 2.910 A) are too long to imply intramolecular coordination.

Electrochemical reduction of phthalyl chloride. A new route for the synthesis of 3-substituted phthalides

Abstract The cathodic reduction, under various conditions, of phthalyl chloride enables efficient synthesis of (E)-[1,1′]biisobenzofuranyliden-3,3′-dion (4), [2]-benzopyrano [4,3-c]-[2]benzopyrano-6, 12-dione (7), 3-chlorophthalide (8), phtalide (9), or (E)-3[α-(benzoyloxy) benzylidene] phthalide (12); the structure of the latter compound was confirmed by X-ray crystallography.