Synthese und Molekülstruktur neuer Ringsysteme aus 1,1,3,3-Tetrachlor-1,3-diphosphapropan

Synthesis and Molecular Structure of new Ring Systems from 1,1,3,3-Tetrachloro-1,3-diphosphapropane 1,1,3,3-Tetrachloro-1,3-diphosphapropane 1 reacts in two different ways to form new heterocycles. Partial oxidation of 1 with tetrachloroorthobenzoquinone furnishes the methylene-bridged λ³P, λ⁵P species 3 . Subsequent reactions with di- and triethylamine lead to the condensed ring system 6 with the P?C bonds connected to a central four-membered ring. Compound 6 displays crystallographic inversion symmetry, a short transannular P? P distance and an extremely distorted tetrahedral coordination geometry at the four-membered ring phosphorus atoms. 1 reacts with 7 to give the heterocycle 8 with a central eight-membered ring involving four phosphorus atoms. The eight – membered ring shows a ?bent”? crown conformation, the condensed five – membered rings display envelope conformation.     

Synthese,Struktur und einige Reaktionen [N-(N′,N′,N″,N″-tetramethyl)-guanidinyl]-substituierter Phosphorylverbindungen

Synthesis, Structure, and some Reactions of N-(N′,N′,N″,N″-tetramethyl)guanidinyl-substituted Phosphoryl Compounds The tetramethylguanidinyl-substituted phosphoryl compounds 1 – 10 were prepared in the reaction of the appropriate chlorophosphoryl compounds with either N′,N′,N″,N″-tetramethylguanidine (HTMG) or N-trimethylsilyl-(N′,N′,N″,N″-tetramethyl)guanidine (TMSTMG). With methyl iodide 1 reacted with N-alkylation to give the ammonium salt 11. 1 reacted with BF₃ · Et₂O at both imino nitrogen atoms with formation of the bis-BF₃-adduct 12 . The X-ray structure determination of phenylphosphonic acid-bis(N′,N′,N″,N″-tetramethylguanidinide) 3 shows shortened PN-bonds and widened PNC-angles, consistent with the partial double bond character of the PN-bond.     

Reactions of Ru3(CO)12 with Diphosphenes — A New Route to 50‐Electron Ru3P2 nido‐Clusters

The reaction of the symmetric diphosphene 2, 4, 6‐(CF₃)₃‐C₆H₂‐P=P‐C₆H₂‐2, 4, 6‐(CF₃)₃ 4 with Ru₃(CO)₁₂ led to the 50‐electron Ru₃P₂ nido‐cluster Ru₃(CO)₉[μ‐P‐C₆H₂‐2, 4, 6‐(CF₃)₃]₂ 5 , which in solution at room temperature displays hindered rotation of the aromatic rings about the C(aryl)—P bonds. The structure of 5 was determined by X‐ray crystal structure analysis; its Ru₃P₂ centre forms a distorted square pyramid with one ruthenium atom at the apex. One of the two C₆H₂(CF₃)₃ groups is also appreciably distorted. Temperature‐dependent ¹⁹F NMR studies of the [A₃M₃X]₂ spin system (A = M = CF₃, X = ³¹P) of 5 indicated a rotational barrier ΔG^≠ of 82.3 kJ mol^‐1 at 141 °C. The same Ru₃P₂ core was obtained by the reaction of the unsymmetric diphosphene Mes*‐P=P‐Mes 11 with Ru₃(CO)₁₂; hindered rotation about the C(aryl)—P bonds was also observed, in this case.     

Hydrolysis in the system LiPF6—propylene carbonate—dimethyl carbonate—H2O

¹⁹F and ³¹P NMR spectroscopy were used to study the kinetics of the hydrolysis of LiPF₆ in the homogenous solvent system propylene carbonate (PC)—dimethyl carbonate (DMC)—H₂O. It was found that the main products of the hydrolysis are HF, LiPO₂F₂ and Li₂PO₃F. The content of POF₃ and PF₅ was negligibly low. We set up a hypothesis that the main factor determining the rate of the process is the so-called ‘secondary’ catalytic effect, caused by solvated H⁺ ions.     

Charge location and fragmentation under electron impact. IV—the behaviour under electron impact of some N-methyl,N′-R-1,2,4-phosphadiazetidine-3-ones and related compounds

The ionization potentials of a series of N-methyl,N′-R-1,2,4-phosphadiazetidine-3-ones and related compounds have been determined. The nature of the highest occupied orbital of the molecules and the use of empirical rules to rationalize the variations in the ionization potentials are discussed. The changes in the fragmentation patterns are related to the different low ionization potential site(s) in each molecule. The occurrence of various rearrangement ions are discussed on a similar basis.     

Intramolecular electrophilic rearrangements in saturated acyclic systems. Reactivity of the zwitterion derived from triisopropylphosphine and ethyl 2-cyanoacrylate with respect to different types of electrophiles

The reactions of the zwitterion derived from triisopropylphosphine and ethyl 2-cyanoacrylate with mercuric chloride and aryl isothiocyanates containing Cl atoms in the ortho positions of the benzene ring follow an unusual pathway because this zwitterion represents latent triisopropylphosphine due to the reversibility of the reaction of triisopropylphosphine with ethyl 2-cyanoacrylate. The molecular structures of the adducts of triisopropylphosphine with 2,6-dichloro- and 2,4,6-trichlorophenyl isothiocyanates were confirmed by X-ray diffraction study. Protonation of the adduct of triisopropylphosphine with 2,6-dichlorophenyl isothiocyanate occurred at the nitrogen atom, whereas methylation with methyl trifluoromethanesulfonate afforded an S-methylation product. The results of X-ray diffraction study of the resulting compounds are presented.     

Synthesis of Tricyclic (λ5)-Phosphoranes; unusual N-demethylation/N-alkylation reactions during the oxidative addition of hexafluoroacetone and tetrachloro-ortho-benzoquinone to benzodiaza-λ3-phosphorinones. Single crystal X-ray diffraction studies of various products

The reaction of methylisatoic acid anhydride 1 with benzylamines led to the N-benzyl-N′-methylanthranilamide derivatives 2 – 4 . Their reaction with phosphorus trichloride furnished the 2-chloro-1-halobenzyl/benzyl-3-methyl-4(1 H)-1,3,2-benzodiazaphosphorin-4-ones 5 – 7 which, upon reaction with bis-(2-chloroethyl)ammonium chloride/triethylamine, were converted into the P-bis-(2-chloroethyl)amino-1-halobenzyl/benzyl-3-methyl-4(1 H)-1,3,2-benzodiazaphosphorin-4-ones 8 – 10 and 12 . With 2-chloroethylammonium chloride/triethyl-amine the P? NHCH₂CH₂Cl-substituted compound 11 was obtained from the P^IIICl-species 6 . The reaction of 8 – 10 and 12 with hexafluoroacetone (HFA) took an unusual course: apart from the oxidative addition of HFA and formation of the perfluoropinacolyl ring system, one of the two CH₂CH₂Cl groups was found to alkylate the CH₃N atom with formation of a five-membered (diazaphospholane) ring in the tricyclic phosphoranes 13 – 16 . The reaction of 11 with HFA also produced a spirophosphorane 17 which involved a λ⁵-oxazaphosphetidine ring system. In the reaction of 8, 10 and 12 with tetrachloro-o-benzoquinone, an oxidative addition reaction with concomitant N-alkylation and formation of the tricyclic phosphoranes 18 – 20 was found to take place. Single crystal X-ray structure determinations are described for the phosphoranes 13, 14 and 16 , and for the precursor compound 9 . The following features are common to the isostructural compounds 13 and 16 and the diethyl ether hemisolvate of 14 : the (λ⁵)-spiro phosphorus atom lies out of the plane of the other atoms of the rings to which it is common, and the dioxaphospholane rings display a twist conformation. In the λ³P-compound 9 the phosphorus atom also lies out of the plane of the other ring atoms.