A simple and highly efficient synthesis of N-phenyl-2-polyfluoroalkyl-4-quinolones from 2-anilinoacetophenone and RFCO2Et

The condensation of 2-anilinoacetophenone with R_FCO₂Et (R_F = CF₂H, CF₃, C₂F₅) in the presence of LiH in THF affords the corresponding N-phenyl-2-polyfluoroalkyl-4-quinolones in excellent yields.     

Phosphinophosphiniden-Phosphorane tBu2P?P = P(R)tBu2 aus Li(THF)2[η2-(tBu2P)2P] und Alkylhalogeniden

The Phosphinophosphinidene-phosphoranes ^tBu₂P? P = P(R)^tBu₂ from Li(THF)₂[η²-(^tBu₂P)₂P] and Alkyl Halides We report the formation of ^tBu₂P? P = P(R)^tBu₂ a and (^tBu₂)₂PR b (with R = Me, Et, ⁿPr, ⁱPr, ⁿBu, PhCH₂, H₂C = CH? CH₂ and CF₃) reactions of Li(THF)₂[η²-(^tBu₂P)₂P] 2 with MeCl, MeI, EtCl, EtBr, ⁿPrCl, ⁿPrBr, ⁱPrCl, ⁿBuBr, PhCH₂Cl, H₂C = CH? CH₂Cl or CF₃Br. In THF solutions the ylidic compounds a predominate, whereas in pentane the corresponding triphosphanes b are preferrably formed. With ClCH₂? CH = CH₂ only b is produced; CF₃Br however yields both ^tBu₂P? P = P(Br)^tBu₂ and ^tBu₂P? P = P(CF₃)^tBu₂, but no b . The ratio of a:b is influenced by the reaction temperature, too. The compounds ^tBu₂P? P = P(Et)^tBu₂ 4a and (^tBu₂P)₂PEt 4 b , e. g., are produced in a ratio of 4:3 at ?70°C in THF, and 1:1 at 20°C; whereas 1:1 is obtained at ?70°C in pentane, and 1:2 at 20°C. Neither ^tBuCl nor H₂C = CHCl react with 2 . The compounds a decompose thermally or under UV irradiation forming ^tBu₂PR and the cyclophosphanes (^tBu₂P)_nP_n.     

Synthesis and some properties of 6-di(tri)fluoromethyl-and 5-di(tri)fluoroacetyl-3-methyl-1-phenylpyrano[2,3-<Emphasis Type="Italic">c</Emphasis>]pyrazol-4(1<Emphasis Type="Italic">H</Emphasis>)-ones

Condensation of 4-acetyl-5-hydroxy-3-methyl-1-phenylpyrazole with R^FCO₂Et (R^F = CF₂H, CF₃) in the presence of LiH affords 4-di(tri)fluoroacetoacetyl-5-hydroxy-3-methyl-1-phenylpyrazoles from which 6-di(tri)fluoromethyl-and 5-di(tri)fluoroacetyl-3-methyl-1-phenylpyrano[2,3-c]pyrazol-4(1H)-ones were synthesized. The reactions of pyrano-pyrazoles with hydrazine hydrate, ethyl mercaptoacetate, or aromatic amines proceed at the C(6) atom with pyrone ring opening and formation of aminoenones, pyrazoles, or thiophenes with the 5-hydroxy-3-methyl-1-phenyl-4-pyrazolyl fragment. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2750–2754, December, 2005.     

Molybdenum(VI) Bis(imido) Complexes: From Frustrated Lewis Pairs to Weakly Coordinating Cations

Molybdenum(VI) bis(imido) complexes [Mo(NtBu)₂(L^R)₂] (R=H 1 a ; R=CF₃ 1 b ) combined with B(C₆F₅)₃ ( 1 a /B(C₆F₅)₃, 1 b /B(C₆F₅)₃) exhibit a frustrated Lewis pair (FLP) character that can heterolytically split H−H, Si−H and O−H bonds. Cleavage of H₂ and Et₃SiH affords ion pairs [Mo(NtBu)(NHtBu)(L^R)₂][HB(C₆F₅)₃] (R=H 2 a ; R=CF₃ 2 b ) composed of a Mo(VI) amido imido cation and a hydridoborate anion, while reaction with H₂O leads to [Mo(NtBu)(NHtBu)(L^R)₂][(HO)B(C₆F₅)₃] (R=H 3 a ; R=CF₃ 3 b ). Ion pairs 2 a and 2 b are catalysts for the hydrosilylation of aldehydes with triethylsilane, with 2 b being more active than 2 a . Mechanistic elucidation revealed insertion of the aldehyde into the B−H bond of [HB(C₆F₅)₃]⁻. We were able to isolate and fully characterize, including by single-crystal X-ray diffraction analysis, the inserted products Mo(NtBu)(NHtBu)(L^R)₂][{PhCH₂O}B(C₆F₅)₃] (R=H 4 a ; R=CF₃ 4 b ). Catalysis occurs at [HB(C₆F₅)₃]⁻ while [Mo(NtBu)(NHtBu)(L^R)₂]⁺ (R=H or CF₃) act as the cationic counterions. However, the striking difference in reactivity gives ample evidence that molybdenum cations behave as weakly coordinating cations (WCC).     

Mono and Bisphosphonates from Perfluoro Olefins and Polyfunctional Fluoro Ketones. Syntheses,Molecular Structure and Derivatives

Perfluoroalkenyl phosphonates were formed along with Me₃SiF using CF₃CF=CF₂, CF₃CH=CF₂, F₅SCF=CF₂ or F₅SCH=CF₂ and silylated phosphites, (R¹O)₂POSiMe₃ (R¹=Et, SiMe₃). This straightforward method could be extended to perfluorobutadienes CF₂=C(R^F)C(R^F)=CF₂ (R^F F=F, CF₃). The formation of CF₃C(=O)P(=O)(OSiMe₃)₂ and further reactions to yield bisphosphonates will be described. Acetylphosphonates, R²C(=O)P(=O)(OSiMe₃)₂ (R²=CH₃, CF₃) reacted with the ketimine, CH₃C(=NiPr)Ph to give α-hydroxy-γ-imino phosphonates. Trifluoroacetylphenol and 2,6-bis(trifluoracetyl)-4-methyl-phenol have been proven to be versatile precursors for α-and γ-hydroxy phosphonates. Intermediates in these reactions were found to be cyclic λ⁵σ⁵P species.     

Diamine‐Catalyzed Addition of ZnEt2 to PhC(O)CF3: Two Mechanisms and Autocatalytic Asymmetric Enhancement

NMR spectroscopic studies of the catalytic addition reaction of ZnEt₂ to PhC(O)CF₃ in the presence of three very efficient catalysts [TMEDA, tBuBOX, and L ; where L is a chiral diamine synthesized from optically pure (R,R)‐1,2‐diphenylethylenediamine and (S)‐2,2′‐bis‐(bromomethyl)‐1,1′‐binaphthalene] reveal large differences in their behavior. For the ligands TMEDA and tBuBOX, the catalysis shows no unusual features and proceeds via [(N?N)Zn(Et){OC(CF₃)(Et)Ph}]. For N?N? L , the observation of autocatalytic asymmetric enhancement during the catalysis, and unusual inverse concentration dependence on the reaction rate, indicate the participation of an additional novel catalytic cycle that goes through a dinuclear intermediate containing one ZnEt₂ and one ZnEt fragment connected by N?N and OR bridges. Interestingly, the ¹⁹F NMR signals of the main product of the reaction ([Zn(Et){OC*(CF₃)(Et)Ph}]₂) allowed us to assess the enantioselectivity of the processes in situ without the assistance of chiral chromatography.     

The first synthesis of 8-aza-2-polyfluoroalkylchromones

The condensation of 3-acetyl-4,6-dimethyl-2-pyridone with R_FCO₂Et in the presence of LiH in dioxane affords corresponding R_F-containing β-diketones, whose dehydration under the action of conc. H₂SO₄ gives 8-aza-5,7-dimethyl-2-polyfluoroalkylchromones.     

Darstellung und Kristallstrukturen von tBu‐substituierten Disiloxanen des Typus tBu2SiX‐O‐SiYtBu2 (X = Y = OH,Br; X = OH,Y = H) und den Addukten tBu3SiOH·(HO3SCF3)0.5·H2O und tBu3SiOLi·(LiO3SCF3)2·(H2O)2

Syntheses and Crystal Structures of tBu‐substituted Disiloxanes tBu₂SiX‐O‐SiYtBu₂ (X = Y = OH, Br; X = OH, Y = H) and of the Adducts tBu₃SiOH·(HO₃SCF₃)_0.5·H₂O and tBu₃SiOLi·(LiO₃SCF₃)₂·(H₂O)₂ The disiloxanes tBu₂SiX‐O‐SiYtBu₂ (X = Y = H, OH) are accessible from the reaction of CF₃SO₂Cl with tBu₂SiHOH or tBu₂Si(OH)₂. By this reaction the disiloxane tBu₂SiH‐O‐SiHtBu₂ is formed together with tBu₂SiH‐O‐SiOHtBu₂. The disiloxanes tBu₂SiX‐O‐SiYtBu₂ (X = Y = Cl, Br) can be synthesized almost quantitatively from tBu₂SiH‐O‐SiHtBu₂ with Cl₂ and Br₂ in CH₂Cl₂. The structures of the disiloxanes tBu₂SiX‐O‐SiYtBu₂ (X = H, Y = OH; X = Y = OH, Br) show almost linear Si‐O‐Si units with short Si‐O bonds. Single crystals of the adducts tBu₃SiOH·(HO₃SCF₃)_0.5·H₂O and tBu₃SiOLi·(LiO₃SCF₃)₂·(H₂O)₂ have been obtained from the reaction of tBu₃SiOH with CF₃SO₃H and of tBu₃SiO₃SCF₃ with LiOH. According to the result of the X‐ray structural analysis (hexagonal, P‐62c), tBu₃SiOLi · (LiO₃SCF₃)₂·(H₂O)₂ features the ion pair [(tBu₃SiOLi)₂(LiO₃SCF₃)₃(H₂O)₃Li]⁺ [CF₃SO₃]^?. The central framework of the cation forms a trigonal Li₆ prism.     

Orienting Effect of the Cage Addends: The Case of Nucleophilic Cyclopropanation of C2‐C70(CF3)8

C₂‐C₇₀(CF₃)₈ was found to be a very promising substrate in the Bingel and the Bingel–Hirsch reactions combining perfect regioselectivity with much higher reactivity compared to its analogs. The reactions with diethyl malonate yield a single isomer of the monoadduct C₇₀(CF₃)₈[C(CO₂Et)₂] and a single C₂‐symmetrical bisadduct C₇₀(CF₃)₈[C(CO₂Et)₂]₂. The Bingel–Hirsch variation is particularly interesting in that it additionally affords, in a similar regioselective manner, the unexpected alkylated derivatives C₇₀(CF₃)₈[CH(CO₂Et)₂]H and C₇₀(CF₃)₈[C(CO₂Et)₂][CH(CO₂Et)₂]H. The novel compounds have been isolated and structurally characterized by means of ¹H and ¹⁹F NMR spectroscopy as well as single‐crystal X‐ray diffraction. The mechanistic and regiochemical aspects of the reaction are explained with the aid of DFT calculations.     

Synthesis of Diaryl Ethers: A Long-Standing Problem Has Been Solved

A breakthrough in the synthesis of diaryl ethers has been achieved as shown in Equation (1). The coupling of phenols with aryl boronic acids in the presence of copper(II ) acetate and a base proceeds under very mild conditions (room temperature) as described simultaneously by Evans et al. and Chan et al. Examples: R¹=2-Cl, 2-I, 2-OMe, 4-tBu, 4-CH₂CH(NHCOOtBu)CO₂Me, 3,5-tBu₂; R²=2-Me, 3-OMe, 3-NO₂, 4-H, 4-F, 4-OMe.     

Molecular ions of 3,3′-bi(2-R-5,5-dimethyl-4-oxopyrrolinylidene) 1,1′-dioxides

The electrochemical reduction of 3,3′-bi(2-R-5,5-dimethyl-4-oxopyrrolinylidene) 1,1′-dioxides (R = CF₃, Me, Ph, Bu^t), which are cyclic dinitrons with conjugated C=C bond, in acetonitrile is an EE process producing stable radical anions and dianions, whereas the electrochemical oxidation is an EEC (R = Me, Ph) or EE process (R = Bu^t) with formation of radical cations (except for the case of R = CF₃) and dications (R = Bu^t) stable under standard conditions. Radical cations of the dioxides with R = Me, Ph, and Bu^t and radical anions of the whole series of the compounds studied, including R = CF₃, were characterized by ESR spectroscopy combined with electrochemical measurements and quantum-chemical calculations. The electrochemical behavior of the Bu^t-substituted dinitron is unique: the EE processes in the region of negative and positive potentials with formation of the dianion, radical anion, radical cation, and dication stable at T = 298 K were observed for the first time within one cycle of potential sweep in the CV curve measured in MeCN. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1148–1154, May, 2005.     

Reaktionen des [η2-{P–PtBu2}Pt(PPh3)2] und [η2-{P–PtBu2}Pt(dppe)] mit Metallcarbonylen. Bildung von [η2-{(CO)5M · PPtBu2}Pt(PPh3)2] (M = Cr,W) und [η2-{(CO)5Cr · PPtBu2}Pt(dppe)]

Coordination Chemistry of P-rich Phosphanes and Silylphosphanes. XVI [1] Reactions of [g²-{P–P^tBu₂}Pt(PPh₃)₂] and [g²-{P–P^tBu₂}Pt(dppe)] with Metal Carbonyls. Formation of [g²-{(CO)₅M · PP^tBu₂}Pt(PPh₃)₂] (M = Cr, W) and [g²-{(CO)₅Cr · PP^tBu₂}Pt(dppe)] [η²-{P–P^tBu₂}Pt(PPh₃)₂] 4 reacts with M(CO)₅ · THF (M = Cr, W) by adding the M(CO)₅ group to the phosphinophosphinidene ligand yielding [η²-{(CO)₅Cr · PP^tBu₂}Pt(PPh₃)₂] 1 , or [η²-{(CO)₅W · PP^tBu₂}Pt(PPh₃)₂] 2 , respectively. Similarly, [η²-{P–P^tBu₂}Pt(dppe)] 5 yields [η²-{(CO)₅Cr · PP^tBu₂}Pt(dppe)] 3 . Compounds 1 , 2 and 3 are characterized by their ¹H- and ³¹P-NMR spectra, for 2 and 3 also crystal structure determinations were performed. 2 crystallizes in the monoclinic space group P2₁/n (no. 14) with a = 1422.7(1) pm, b = 1509.3(1) pm, c = 2262.4(2) pm, β = 103.669(9)°. 3 crystallizes in the triclinic space group P1 (no. 2) with a = 1064.55(9) pm, b = 1149.9(1) pm, c = 1693.2(1) pm, α = 88.020(8)°, β = 72.524(7)°, γ = 85.850(8)°.     

Quasi‐living copolymerization of ethylene with 1‐hexene by heteroligated (salicylaldiminato β‐enaminoketonato) titanium complexes

A series of heteroligated (salicylaldiminato)(β‐enaminoketonato)titanium complexes [3‐Bu^t‐2‐OC₆H₃CH = N(C₆F₅)] [PhN = C(R₁)CHC(R₂)O]TiCl₂ [ 3a : R₁ = CF₃, R₂ = ^tBu; 3b : R₁ = Me, R₂ = CF₃; 3c : R₁ = CF₃, R₂ = Ph; 3d : R₁ = CF₃, R₂ = C₆H₄Ph(p ); 3e : R₁ = CF₃, R₂ = C₆H₄Ph(o ); 3f : R = CF₃, R₂ = C₆H₄Cl(p ); 3g : R₁ = CF₃; R₂ = C₆H₃Cl₂(2,5); 3h : R₁ = CF₃, R₂ = C₆H₄Me(p )] were investigated as catalysts for ethylene (co)polymerization. In the presence of modified methylaluminoxane as a cocatalyst, these complexes showed activities about 50%–1000% and 10%–100% higher than their corresponding bis(β‐enaminoketonato) titanium complexes for ethylene homo‐ and ethylene/1‐hexene copolymerization, respectively. They produced high or moderate molecular weight copolymers with 1‐hexene incorporations about 10%–200% higher than their homoligated counterpart pentafluorinated FI‐Ti complex. Among them, complex 3b displayed the highest activity [2.06 × 10⁶ g/mol_Ti?h], affording copolymers with the highest 1‐hexene incorporations of 34.8 mol% under mild conditions. Moreover, catalyst 3h with electron‐donating group not only exhibited much higher 1‐hexene incorporations (9.0 mol% vs. 3.2 mol%) than pentafluorinated FI‐Ti complex but also generated copolymers with similar narrow molecular weight distributions (M _w/M _n = 1.20–1.26). When the 1‐hexene concentration in the feed was about 2.0 mol/L and the hexene incorporation of resultant polymer was about 9.0 mol%, a quasi‐living copolymerization behavior could be achieved. ¹H and ¹³C NMR spectroscopic analysis of their resulting copolymers demonstrated the possible copolymerization mechanism, which was related with the chain initiation, monomer insertion style, chain transfer and termination during the polymerization process. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 2787–2797     

Synthesen und NMR‐Untersuchungen von Salzen mit den neuen Anionen [PtXn(CF3)6‐n]2— (n = 0 ‐ 5, X = F,OH, Cl,CN) und die Kristallstrukturanalyse von K2[(CF3)2F2Pt(μ‐OH)2PtF2(CF3)2]·2H2O

Syntheses and NMR Spectroscopic Ivestigations of Salts containing the Novel Anions [PtX_n(CF₃)_6‐n]^2— (n = 0 ‐ 5, X = F, OH, Cl, CN) and Crystal Structure of K₂[(CF₃)₂F₂Pt(μ‐OH)₂PtF₂(CF₃)₂]·2H₂O The first syntheses of trifluoromethyl‐complexes of platinum through fluorination of cyanoplatinates are reported. The fluorination of tetracyanoplatinates(II), K₂[Pt(CN)₄], and hexacyanoplatinates(IV), K₂[Pt(CN)₆], with ClF in anhydrous HF leads after working up of the products to K₂[(CF₃)₂F₂Pt(μ‐OH)₂PtF₂(CF₃)₂]·2H₂O. The structure of the salt is determined by a X‐ray structure analysis, P2₁/c (Nr. 14), a = 11.391(2), b = 11.565(2), c = 13.391(3)Å, β = 90.32(3)°, Z = 4, R₁ = 0.0326 (I > 2σ(I)). The reaction of [Bu₄N]₂[Pt(CN)₄] with ClF in CH₂Cl₂ generates mainly cis‐[Bu₄N]₂[PtCl₂(CF₃)₄] and fac‐[Bu₄N]₂[PtCl₃(CF₃)₃], but in contrast that of [Bu₄N]₂[Pt(CN)₆] with ClF in CH₂Cl₂ results cis‐[Bu₄N]₂[PtX₂(CF₃)₄], [Bu₄N]₂[PtX(CF₃)₅] (X = F, Cl) and [Bu₄N]₂[Pt(CF₃)₆]. In the products [Bu₄N]₂[PtX_n(CF₃)_6‐n] (X = F, Cl, n = 0—3) it is possibel to exchange the fluoro‐ligands into chloro‐ and cyano‐ligands by treatment with (CH₃)₃SiCl und (CH₃)₃SiCN at 50 °C. With continuing warming the trifluoromethyl‐ligands are exchanged by chloro‐ and cyano‐ligands, while as intermediates CF₂Cl and CF₂CN ligands are formed. The identity of the new trifluoromethyl‐platinates is proved by ¹⁹⁵Pt‐ and ¹⁹F‐NMR‐spectroscopy.     

Reactions of 3-(Polyfluoroalkyl)propane-1,2,3-trione-2-oximes with Diaminoarenes

Novel quinoxaline derivatives have been synthesized via the reaction of 3-trifhioromethyl-1,2,3-propanetrione-2-oximes with 1,2-diaminobenzene or 2,3-diaminonaphthalene: 2-trifluoromethyl-3-aroylquinoxaline and 2-trifluoromethyl-3-aroylbenzo[g]quinoxaline. Under similar conditions, 3-R^F-1,2,3-propanetrione-2-oximes [R^F = C₃F₇, H(CF₂)₄, C₄F₉, and C₆F₁₃] with the same diaminoarenes have given a mixture of the condensation and fragmentation products in different ratios. The structure of (4-methylphenyl)[3-(tri-fluoromethyl)benzo[g]quinoxalin-2-yl]methanone has been elucidated by means of X-ray diffraction analysis.

     

Intermolecular steric hindrance in 7-acylamino-[1H]-2-oxo-1,8-naphthyridines: NMR,ESI-MS,IR, and DFT calculation studies

Abstract  

Intermolecular interactions of 7-(RCONH)-[1H]-2-oxo-1,8-naphthyridines (R = Me, Et, i-Pr, t-Bu, 1-adamantyl (1-Ad), CF₃, and C₂F₅) containing ADAD quadruple hydrogen bonding motif were studied by liquid and solid state NMR, ESI-MS, IR, and DFT calculations. ¹H NMR was used to determine the dimerization constants of i-Pr and 1-Ad congeners in CDCl₃. ¹³C and ¹⁵N cross-polarization (CP) magic angle spinning (MAS) NMR data suggest that compounds possess similar solid state structures. Further, mass spectral data reveal that in gas phase both Me and 1-Ad derivatives form also multimers due to lack of competitive solvent interactions. The structures of the gas phase multimers depend on the size of the alkyl group. These results are in agreement with quantum chemical calculations. Geometry optimization and ¹H NMR spectra show that in dimers that carry bulky alkyl groups (t-Bu and 1-Ad) certain hydrogen bonds are weaker than in Me, Et, and i-Pr derivatives while strong electron acceptors, CF₃ and C₂F₅, deshields hydrogen bonded protons but creates significant electronic F/O repulsion yielding lowering of the energy of interaction. The influence of steric effect on dimerization of quadruply hydrogen bonded dimers was correlated with the Taft E _s values.     

Molecular mechanics of peroxides. I. Parametrization and conformational analysis of linear compounds

A force field has been developed for use in MM2 calculations of geometric and energy data for linear peroxides R₁? O? O? R₂ and tested in some of them (R₁, R₂ = H, Me, Et, Prⁱ, Bu^t). The field obtained yield results that agree considerably better with experimental and ab initio data than those afforded by the only set of estimated parameters hitherto available.     

Reaktionen von tBu2P?PP(Br)tBu2 mit Phosphanen. Ein Weg zu unterschiedlich substituierten Phosphinophosphiniden-Phosphoranen

Reactions of ^tBu₂P? P?P(Br)^tBu₂ with Phosphanes A Route to Variously Substituted Phosphinophosphinidene-phosphoranes ^tBu₂P? P?P(Br)^tBu₂ 1 reacts with PR₃ [R₃ = Et₃, ^tBu₃, Ph₃, (NMe₂)₃, (NEt₂)₃, (NEt₂)₂Me, Me₂SiMe₃] according to ^tBu₂P? P?P(Br)^tBu₂ + PR₃ → ^tBu₂P? P?PR₃ + ^tBu₂PBr While 1 decomposes above ?30°C yielding ^tBu₂PBr and the cyclophosphanes (^tBu₂P)₃P₃ and (^tBu₂P)₄P₄, there is no condensation to give any cyclophosphanes from the intermediately formed ^tBu₂P? P in the presence of PR₃. The chlorophosphanes ^tBu₂PCl, ^tBuPPhCl, (Et₂N)₂PCl and Ph₂PCl as well as (CF₃)₂PBr react quite analogously to the above equation yielding ^tBu₂P? P?P(Cl)^tBu₂, ^tBu₂P? P?P^tBuPhCl, ^tBu₂P? P?P(NEt₂)₂Cl and ^tBu₂P? P?P(NEt₂)₂Br.     

Komplexchemie P-reicher Phosphane und Silylphosphane. XIV. Phosphinophosphiniden tBu2P?P als Ligand in den Pt-Komplexen [η2-{tBu2P?P}Pt(PPh3)2] und [η2-{tBu2P?P}Pt(PEtPh2)2]

Coordination Chemistry of P-rich Phosphanes and Silylphasphanes. XIV. The Phosphinophosphinidene ^tBu₂P? P as a Ligand in the Pt Complexes [η²-{^tBu₂P? P}Pt(PPh₃)₂] and [η²-{^tBu₂P? P}Pt(PEtPh₂)₂] [η²-{^tBu₂P? P}Pt(PPh₃)₂ 1 and [η²-{^tBu₂P? P}Pt(PEtPh₂)₂] 2 are the first complex compounds of ^tBu₂P? P 5 . They are formed in the reaction of ^tBu₂P? P ? P(Me)^tBu₂ 3 with [η²-{H₂C ? CH₂}Pt(PPh₃)₂] 6 or [η²-{H₂C ? CH₂}Pt(PEtPh₂)₂] 7 , respectively. Compound 1 is less stable than 2 and reacts on to [η²-{^tBu₂P? P} Pt(PPh₃)(P^tBu₂Me)] 10 with the coincidently formed ^tBu₂PMe. The molecular structures of 1 and 2 were derived from their ¹H and ³¹P-NMR spectra, 2 was additionally characterized by a X ray structure determination. 2 crystallizes in the monoclinic space group P2₁/n with a = 1222.36(7) pm, b = 1770.7(1) pm, c = 1729.7(1) pm, β = 108.653(6)°.     

Reactions of [Re(NO)2(PR3)2][BArF 4] complexes with phenylacetylene

The reaction of [Re(NO)₂(PR₃)₂][BAr^F ₄] (R = cyclo-C₆H₁₃ (1a), Prⁱ (1b); [BAr^F ₄]^– = [B(3,5-(CF₃)₂C₆H₃)₄]) with phenylacetylene in the presence of a non-nucleophilic base, like 2,6-bis(tert-butyl)pyridine (BTBP) or Bu^tOK, affords the phenylethynyl complexes [Re(CCPh)(NO)₂(PR₃)₂] (R = cyclo-C₆H₁₃ (2a); Prⁱ (2b)) in moderate yields. In the absence of a base, complexes 1a and 1b are transformed into the compounds [Re(CCPh)(CH=C(Ph)ONH)(NO)(PR₃)₂][BAr^F ₄] (3a and 3b, respectively). The structure of complex 3a was confirmed by X-ray diffraction analysis. The latter reaction is proposed to be initiated by deprotonation of the terminal alkyne H atom by the bent nitrosyl ligand followed by the subsequent 1,3-dipolar addition of the ReN(H)O moiety to phenylacetylene.