Reactions of P-donor ligands with N-silyl(halogeno)organophosphoranimines: formation of cations with P-P coordination bonds and poly(alkyl/aryl)phosphazenes at ambient temperature.

A series of phosphine donor-stabilized N-silylphosphoranimine salts [R'3P.PR2=NSiMe3]+Br- were prepared from the direct reaction between the phosphoranimines BrR2P=NSiMe3 (R = Me, OCH2CF3) and the tertiary phosphines nBu3P and Me3P. The 1JPP values of these salts exhibit an unusual dependence on the substituents at the phosphoranimine acceptor and appear to reflect an electronic push-pull mechanism.

Neutral high-potential nickel triad bisdithiolenes: structure and solid-state NMR properties of Pt[S2C2(CF3)2]2.

X-ray crystallography and solid-state NMR techniques were used to determine the structure and 195Pt NMR chemical shift (CS) tensor of Pt[S2C2(CF3)2]2. This is the first reported crystal structure of a highly oxidizing (CN- or CF3-substituted) neutral bis(dithiolene) complex of a Ni triad metal in its pure form. The 195Pt NMR CS tensor is highly anisotropic and asymmetric; the latter property is attributed to the noninnocent nature of the ligand.

Phosphine-mediated dehalogenation reactions of trichloro(N-silyl)phosphoranimines.

The reaction of N-(trimethylsilyl)phosphoranimine Cl3P=NSiMe3 (1) with nBu3P or Ph3P yields the N-(dichlorophosphino)phosphoranimines nBu3P=NPCl2 (4a) or Ph3P=NPCl2 (4b), respectively. Detailed studies of this reaction indicate a mechanism that involves the reductive dechlorination of 1 by the tertiary phosphine to yield nBu3PCl2 (5a) or Ph3PCl2 (5b) with the apparent formation of the transient chlorophosphinimine ClP=NSiMe3 (6), followed by condensation of 5a or 5b with 1 to form 4a or 4b and Me3SiCl. Convincing evidence for the proposed mechanism was revealed by studies of the analogous reaction between the N-(triphenylsilyl)phosphoranimine Cl3P=NSiPh3 (8) with nBu3P and Ph3P.

New insight into reactions of Ni(S2C2(CF3)2)2 with simple alkenes: alkene adduct versus dihydrodithiin product selectivity is controlled by [Ni(S2C2(CF3)2)2]- anion.

The nickel bis(dithiolene) complex Ni(S2C2(CF3)2)2 employs its sulfur centers in reactions with alkenes, and stable interligand S-bonded alkene adducts can be formed. The present study shows that the selectivity of alkene binding to charge-neutral Ni(S2C2(CF3)2)2 is influenced by the anion [Ni(S2C2(CF3)2)2]-. In the absence of anion, formation of substituted dihydrodithiins (intraligand addition) dominates, whereas the presence of anion allows for the formation of stable interligand adducts.

Identification of 1,3-dialkylimidazolium salt supramolecular aggregates in solution.

The nature of the interactions between 1,3-dialkylimidazolium cations and noncoordinating anions such as tetrafluoroborate, hexafluorophosphate, and tetraphenylborate has been studied in the solid state by X-ray diffraction analysis and in solution by (1)H NMR spectroscopy, conductivity, and microcalorimetry. In the solid state, these compounds show an extended network of hydrogen-bonded cations and anions in which one cation is surrounded by at least three anions and one anion is surrounded by at least three imidazolium cations. In the pure form, imidazolium salts are better described as polymeric supramolecules of the type {[(DAI)(3)(X)](2+)[(DAI)(X)(3)](2-)}(n) (where DAI is the dialkylimidazolium cation and X is the anion) formed through hydrogen bonds of the imidazolium cation with the anion.

Easily prepared air- and moisture-stable Pd-NHC (NHC=N-heterocyclic carbene) complexes: a reliable, user-friendly, highly active palladium precatalyst for the Suzuki-Miyaura reaction.

The synthesis of NHC-PdCl(2)-3-chloropyridine (NHC=N-heterocyclic carbene) complexes from readily available starting materials in air is described. The 2,6-diisopropylphenyl derivative was found to be highly catalytically active in alkyl-alkyl Suzuki and Negishi cross-coupling reactions. The synthesis, ease-of-use, and activity of this complex are substantial improvements over in situ catalyst generation and all current Pd-NHC complexes.

A cobalt(III)-salen complex with an axial substituent in the diamine backbone: stereoselective recognition of amino alcohols.

A cobalt(III)-salen complex (3) with an axial substituent on the diamine backbone has been synthesized. Crystal structure reveals that the axial substituent (p-nitrophenyl group) is positioned in close proximity to the metal binding site. The stereoselectivity of the cobalt complex for binding amino alcohols increases with increasing steric bulk of the amino alcohol from alaninol (2.

Preorganization in highly enantioselective diaza-Cope rearrangement reaction.

Crystal structure and activation entropy data indicate that H-bond directed diaza-Cope rearrangement of chiral diimines takes place with a high degree of preorganization. CD spectroscopy and HPLC data show that there is inversion of stereochemistry for the reaction with excellent enantioselectivity.

Reversible skeletal transmetalations of inorganic rings: isolation of aluminatophosphazenes, a zwitterionic phosphazene, and a donor-stabilized alumazine-phosphazene hybrid cation.

Synthesis of the cyclic aluminatophosphazene ring N(PCl2NMe)2AlMeCl (5) has been achieved via a skeletal transmetalation reaction between AlMe3 and the boratophosphazene N(PCl2NMe)2BCl2 (1). Reaction of 5 with various halogenated Lewis acids such as GaCl3 yielded the fully chlorinated aluminum heterocycle N(PCl2NMe)2AlCl2 (8) through a methyl-halogen exchange process. In contrast, treatment of 5 with excess AlMe3 resulted in complete methylation at aluminum to give N(PCl2NMe)2AlMe2 (6).

Methyl 2-(4-ferrocenylbenzamido)thiophene-3-carboxylate and ethyl 2-(4-ferrocenylbenzamido)-1,3-thiazole-4-acetate, a unique ferrocene derivative containing a thiazole moiety.

The conformations and hydrogen bonding in the thiophene and thiazole title compounds, [Fe(C5H5)(C20H14NO3S)], (I), and [Fe(C5H5)(C19H17N2O3S)], (II), are discussed. The sequence (C5H4)-(C6H4)-(CONH)-(C4H2S)-(CO2Me) of rings and moieties in (I) is close to being planar; all consecutive interplanar angles are less than 10 degrees . An intramolecular N-H.

Rhodium-catalyzed dehydrocoupling of fluorinated phosphine-borane adducts: synthesis, characterization, and properties of cyclic and polymeric phosphinoboranes with electron-withdrawing substituents at phosphorus.

The dehydrocoupling of the fluorinated secondary phosphine-borane adduct R2PH.BH3 (R = p-CF3C6H4) at 60 degrees C is catalyzed by the rhodium complex [{Rh(mu-Cl)(1,5-cod)}2] to give the four-membered chain R2PH-BH2-R2P-BH3. A mixture of the cyclic trimer [R2P-BH2]3 and tetramer [R2P-BH2]4 was obtained from the same reaction at a more elevated temperature of 100 degrees C.

Chemistry of ruthenium(II) monohydride and dihydride complexes containing pyridyl donor ligands including catalytic ketone H2-hydrogenation.

In this study we determine the changes to the properties of dihydride catalysts for ketone H2-hydrogenation by successively replacing the amine donors in the known dach complex RuH2(PPh3)2(dach) (2a), dach = 1,2-(R,R)-diaminocyclohexane, with one pyridyl group in the corresponding 2-(aminomethyl)pyridine (ampy) complexes RuH2(PPh3)2(ampy) (2b) and with two pyridyl groups in the complexes RuH2(PPh3)2(bipy) (2c) and RuH2(PPh3)2(phen) (2d). The ruthenium monohydride complex, (OC-6-54)-RuHCl(PPh3)2(ampy), (1b with Cl trans to H) was prepared by the addition of 1 equiv of ampy to RuHCl(PPh3)3 in THF. Treatment of the monohydride complex with K[BH(sec-Bu)3] in THF or KOtBu/H2 in toluene resulted in the formation of a mixture of at least two isomers of the highly reactive, air-sensitive ruthenium dihydride complex 2b.

A succession of isomers of ruthenium dihydride complexes. Which one is the ketone hydrogenation catalyst?

Reaction of RuHCl(PPh(3))(2)(diamine) (1a, diamine = (R,R)-1,2-diaminocyclohexane, (R,R)-dach; 1b, diamine = ethylenediamine, en) with KO(t)Bu in benzene quickly generates solutions of the amido-amine complexes RuH(PPh(3))(2)(NHC(6)H(10)NH(2)), (2a'), and RuH(PPh(3))(2)(NHCH(2)CH(2)NH(2)), (2b'), respectively. These solutions react with dihydrogen to first produce the trans-dihydrides (OC-6-22)-Ru(H)(2)(PPh(3))(2)(diamine) (t,c-3a, t,c-3b). Cold solutions (-20 degrees C) containing trans-dihydride t,c-3a react with acetophenone under Ar to give (S)-1-phenylethanol (63% ee).

Highly metallized polymers: synthesis, characterization, and lithographic patterning of polyferrocenylsilanes with pendant cobalt, molybdenum, and nickel cluster substituents.

High molecular weight, soluble, air- and moisture-stable, highly metallized (>25 wt% metal) polyferrocenylsilanes (PFS) [Fe(eta-C5H4)2Si(Me){Co2(CO)6C2Ph}]n (Co-PFS), [Fe(eta-C5H4)2Si(Me){Mo2-Cp2(CO)4C2Ph}]n (Mo-PFS), and [Fe(eta-C5H4)2Si(Me){Ni2Cp2C2Ph}]n (Ni-PFS) containing pendant cobalt, molybdenum, and nickel clusters, respectively, have been prepared via macromolecular clusterization of an acetylide-substituted PFS [Fe(eta-C5H4)2Si(Me)C(triple bond)CPh]n with [Co(2)(CO)8], [{MoCp(CO)(2)}2], or [{NiCp(CO)}2]. The extent of clusterization achieved was in the range of 70-75%. All three highly metallized polymers were demonstrated to function as negative-tone resists in electron-beam lithography, while Co-PFS and Mo-PFS were successfully patterned by UV-photolithography, allowing the fabrication of micron-sized bars, dots, and lines.

Ring-opening protonolysis of sila[1]ferrocenophanes as a route to stabilized silylium ions.

The ring-opening reactions of a series of sila[1]ferrocenophanes with protic acids of anions with various degrees of noncoordinating character have been explored. Ferrocenyl-substituted silyl triflates FcSiMe2OTf (5 a) and Fc(3)SiOTf (5 b) (Fc=(eta5-C5H4)Fe(eta5-C5H5)) were synthesized by means of HOTf-induced ring-opening protonolysis of strained sila[1]ferrocenophanes fcSiMe2 (3 a) and fcSiFc2 (3 b) (fc=(eta5-C5H4)2Fe). Reaction of 3 a and 3 b with HBF4 yielded fluorosubstituted ferrocenylsilanes FcSiMe2F (6 a) and Fc3SiF (6 b) and suggested the intermediacy of a highly reactive silylium ion capable of abstracting F- from the [BF4]- ion.

Supramolecular structures of 1-phenylethylammonium tartrates.

The structures of six 1-phenylethylammonium tartrates have been determined and in each of them a distinctive hydrogen-bonded anion substructure can be identified. (S)-1-Phenylethylammonium (R,R)-hydrogen tartrate [(I), P21, Z'=1] contains anion sheets built from a single type of R4(4)(22) ring with cations pendent, via three N-H..

Chemistry of phosphine-borane adducts at platinum centers: dehydrocoupling reactivity of Pt(II) dihydrides with P-H bonds.

The reaction of the Pt(II) dihydride complex cis-[PtH2(dcype)](dcype = 1,2-bis(dicyclohexylphosphino)ethane) with the primary or secondary phosphine-borane adducts PhRPH x BH3(R = H, Ph) was found to exclusively afford the mono-substituted complexes cis-[PtH(PPhR x BH3)(dcype)](1: R = H; 2: R = Ph)via a dehydrocoupling reaction between Pt-H and P-H bonds. Similar reactivity was observed between the uncoordinated phosphines PhRPH (R = H, Ph) and cis-[PtH2(dcype)], which gave cis-[PtH(PPhR)(dcype)](4: R = H; 5: R = Ph). The complexes were characterized by 1H, 11B, 13C and 31P NMR spectroscopy, IR, MS and, in the case of 2, X-ray crystallography that confirmed the cis geometries.

Reactions of 2-indolylphosphines with Ru3(CO)12: cluster capping with mu 3,eta 2-indolylphosphine as an anionic six-electron P,N-donor ligand.

Stepwise bidentate coordination of the novel indolylphosphine ligands HL (1, HL = P(C(6)H(5))(2)(C(9)H(8)N)(diphenyl-2-(3-methylindolyl)phosphine); 2, HL = P(C(6)H(5))(C(9)H(8)N)(2)(phenyldi-2-(3-methylindolyl)phosphine); and 3, HL = P(C(6)H(5))(C(17)H(12)N(2))(di(1H-3-indolyl)methane-(2,12)-phenylphosphine)) to the ruthenium cluster Ru(3)(CO)(12) is demonstrated. Reactions of 1-3 with Ru(3)(CO)(12) led to the formation of Ru(3)(CO)(11)(HL) (4-6), in which HL is mono-coordinated through the phosphorus atom. The X-ray structures of 4-6 show that the phosphorus atom is equatorially coordinated to the triruthenium core.

Isolation and characterization of the first stable bicarbonato complex in a nickel(II) system: identification of unusual monodentate coordination.

The stable monodentate Lindskog type bicarbonate nickel(ii) complex and its isomer have been prepared and fully characterized.

(R)-(+)-2,2'-Bis(diphenylphosphinoyl)-1,1'-binaphthyl.

The title compound, BINAP oxide, C(44)H(32)O(2)P(2), (I), was synthesized by direct oxidation of (R)-(+)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP) with tert-butyl hydroperoxide in toluene solution. The angle between the naphthyl planes of the binaphthyl group is 94.17 (3) degrees.

(Acetonitrile-N)(o-benzoquinone diimine-N,N')chloro-trans-bis(triphenylphosphine-P)ruthenium(II) hexafluorophosphate 0.25-hydrate.

The Ru atom in the title compound, [RuCl(CH(3)CN){P(C(6)H(5))(3)}(2){C(6)H(4)(NH)(2)}]PF(6).0.25H(2)O, has a six-coordinate octahedral geometry, with a trans arrangement of the triphenylphosphine groups.

(o-Benzoquinone diimine-N,N')dichlorobis(triphenylphosphine-P)ruthenium(II) 1.33-methanol 0.33-dichloromethane solvate.

The Ru atom in the title compound, [RuCl(2){P(C(6)H(5))(3)}(2){C(6)H(4)(NH)(2)}].1.33CH(3)OH.