Holger Thönnessen

Preparation and structures of 1-dimethylamino-2-bis(dimethylamino)- and 1-chloro-2-bis(diethylamino)-1-phospha-2-phosphonium acenaphthene: the first examples of the 1,2-dihydro-1,2-diphospha-acenaphthene ring system

Abstract This paper describes the preparation of 1,8-bis[bis(dimethylamino)phosphino]naphthalene ( 2a ) and the attempted preparation of its isopropyl analogue 2c , which led to the formation of 1-naphthyl-bis(diisopropylamino)phosphine ( 4 ), and to other unidentified products. The X-ray structures of 2a and 4 are discussed in comparison to those of 1,8-bis[bis(diethylamino)phosphino]naphthalene ( 2b ) and 1-naphthyl-di- tert -butylphosphine ( 5 ), respectively. In the structures of 2a , 2b and 4 the (R 2 N) 2 P groups (R=alkyl) are eclipsed with respect to the naphthalene plane, whereas the R 2 P groups (R=alkyl or aryl) in 5 , as in 1,8-bis(diorganophosphino)naphthalenes in general, adopt a conformation between bisecting and eclipsed. Furthermore, the reactions of 2a and 2b with BX 3 ether adducts (X=F, Cl) are described, which furnished the heterocyclic [σ 3 P–σ 4 P + ]-diphosphorus compounds, 1-dimethylamino-2-bis(dimethylamino)-, 1-diethylamino-2-bis(diethylamino)- and 1-chloro-2-bis(diethylamino)-1-phospha-2-phosphonium-acenaphthene ( 6a , 6b and 7b ); the first examples of the 1,2-dihydro-1,2-diphospha-acenaphthene ring system. The X-ray structures of 6a and 7b display a relief of strain compared to the parent bis-aminophosphines 2a and 2b , quantified by negative splay angles [−7.89° ( 6a ) and −9.40° ( 7b ); cf. +12.16° ( 2a ) and +12.0° ( 2b )] and the bonded [225.38 ( 6a ) and 223.16 ( 7b ) pm] compared to the non-bonded phosphorus–phosphorus distances [311.9 ( 2a ) and 311.7 ( 2b ) pm]. A mechanism is discussed for the formation of 6b and 7b from 2b and gaseous hydrogen chloride.

Reactions of [Ru3(CO)10(μ-Ph2PCH2PPh2)] with secondary phosphines R2Ph involving bulky substituents (R tBu, 1-Ad, Cy); X-ray crystal structures of [Ru3(CO)6(μ-H)2(μ-PCy2)2(μ-Ph2PCH2PPh2)] and the electron-deficient carbonyl cluster [Ru3(μ-CO)(CO)4(μ3-H)(μ-H)(μ-PtBu2)2(μ-Ph2PCH2PPh2)]

The reaction of [Ru3(CO)10(μ-dppm)] (1) with secondary phosphines R2PH (R  tBu, 1-Ad) in heptane under reflux leads to th electron-deficient metal cluster complexes [Ru3(μ-CO)(CO)4(μ3-H)(μ-H)(μ-PR2)2(μ-dppm)] (R  tBu 4; R  1-Ad 5) in good yields. The reactions yield first the monosubstituted compounds [Ru3(CO)9(R2PH)(μ-dppm)] (R  tBu, 2; R  1-Ad 3), which could be isolated in yields up to 85% after 1 h in refluxing THF. The related reaction of 1 with the less bulky phosphine Cy2PH in heptane under reflux gave the new electronically saturated complex [Ru3(CO)6(μ-H)2(μ-PCy2)2(μ-dppm)] (7). In this case the intermediate [Ru3(CO)9(Cy2PH)(μ-dppm)] (6) could also be isolated. Compounds 4 and 5 seem to be coordinatively saturated, in that no reaction with carbon monoxide or dihydrogen was observed, either under normal conditions or under elevated pressure. The molecular structures of 4 and 7 were determined by single-crystal X-ray studies (dppm  Ph2PCH2PPh2; Ad  Adamantyl).

ZWITTERIONIC SPECIES FROM TRIISOPROPYLPHOSPHINE AND 2-CYANOACRYLATES: SYNTHESIS, STRUCTURE AND PROPERTIES

Abstract Triisopropylphosphine reacts with 2-cyanoacrylates with formation of the P-zwitterionic species 2a and 2b. The reaction of 2b with trimethylsilyltriflate, in the presence of traces of water, leads to the phosphonium triflate 3. 2b is alkylated at the carbon atom with methyl iodide with formation of the phosphonium iodide 4. The initially formed adducts of the zwitterionic species 2a and 2b with tosyl azide and with tosyl isocyanate are thermodynamically unstable. In the first case, the final products of the reaction are tosyl iminotriisopropylphosphine imide 6 and 2-cyanoacrylate polymers. In the second case, the reaction leads to the zwitterionic product 8, and, in the presence of traces of water, to the molecular complexes 9a and 9b. The reaction of the zwitterionic species 2a and 2b with methylisocyanate proceeds in an unusual way, resulting in the formation of the zwitterionic species 12a and 12b, as a result of the insertion of methylisocyanate into the C[sbnd]C bond of the starting zwitteri...

N-(N′, N′, N″, N″-tetramethyl) guanidine-substituted phosphines as monodentate, bidentate or tridentate ligands in transition metal chemistry

The diorganophosphinous-N-(N′, N′, N″, N″-tetramethyl) guanidinides 1a and 1b and the organophosphonous-bis-N-(N′, N′, N″, N″-tetramethyl)guanidinides 2 and 3 are used as ligands towards carbonyls of zerovalent transition metals. In most cases coordination via phosphorus is observed. 1b and 2 act as PN-donors towards the (tetracarbonyl)molybdenum fragment, forming chelate complexes involving one five-membered ring. 3 acts as a PNN′-donor towards molybdenum carbonyls, forming a bicyclic chelate complex. X-ray structure determinations were performed for the octacarbonyldimanganese compound 7, the tricarbonylnickel complex 8 and the tetracarbonyliron derivative 10. The dimanganese compound 7 was found to be diaxially substituted with short MnC bonds but standard MnP bond lengths. The nickel compound 8 exhibited short PNi bonds, long NiC bonds and short CO bonds, consistent with enhanced π-back donation from metal to phosphorus. The coordination geometry at the iron atom in 10 was found to be trigonal bipyramidal with phosphorus in the axial position, strongly distorted towards square pyramidal.

Darstellung von Bis-(2-chlorethyl)amino-substituierten Diazaphosphorinonen. Reversible oxidative Addition von Hexafluoraceton an σ3λ3-Phosphor-Verbindungen. Synthese von σ5λ5-Spirophosphoranen und deren Zersetzung

Durch Umsetzung von 1-Methyl-pyrido[3,2-e]-3,1-oxazin-2,4-dion (1) mit Benzylaminen wurden die Aminonicotinsaureamide 2–4 gebildet. Die anschliesende Umsetzung mit Phosphortrichlorid lieferte die P-Chlor-pyridodiazaphosphorinone 5–7, die durch Umsetzung mit Bis-(2-chlorethyl)ammoniumchlorid/Triethylamin in die entsprechenden P-bis-(2-chlorethyl)amino-substituierten Pyridodiazaphosphorinone 8–10 uberfuhrt wurden. Das P-Chlor-benzodiazaphosphorinon 11 wurde mit 2-Chlorethylammoniumchlorid/Triethylamin zum 2-Chlorethylamino-substituierten Derivat 12 umgesetzt. Durch Oxidation der σ3Diazaphosphorinone 8, 9, 12 und 13 mit dem Harnstoff-Wasserstoffperoxid-(1 : 1)-Addukt wurden die entsprechenden Phosphorylderivate 14–17 erhalten. Die oxidative Addition von Hexafluoraceton (HFA) an das σ3-Diazaphosphorinon 18 fuhrte unter Abspaltung von Methylchlorid zu dem tricyclischen Phosphoran 19 b. Die Spirophosphorane 21–23 wurden durch Reaktion der Verbindungen 8, 9 und 13 mit HFA gebildet. Es wurden NMR-Untersuchungen hinsichtlich der Zersetzung der bicyclischen Phosphorane 20 a, 22 und 23 unternommen. Die oxidative Addition von HFA an Diazaphosphorinone stellte sich dabei als reversibel heraus. Von den Verbindungen 17 und 19 b wurden Rontgenstrukturanalysen angefertigt, die die erwartete Konnektivitat bestatigen. Verbindung 17 weist kurze C–H…O-Wasserstoffbrucken auf (H…O 234 pm). Verbindung 19 kristallisiert mit zwei unabhangigen Molekulen, die sich u. a. in der Ausrichtung der Chlorethylgruppen unterscheiden. Synthesis of Bis-(2-chloroethyl)amino-substituted Diazaphosphorinones. Reversible Oxidative Addition of Hexafluoroacetone to σ3λ3-Phosphorus Compounds. Synthesis of σ5λ5-Spirophosphoranes and their Decomposition The reaction of 1-methyl-pyrido[3,2-e]-3,1-oxazin-2,4-dione (1) with benzylamines led to the aminonicotinic acid amides 2–4. Their reaction with phosphorus trichloride furnished the P-chloro-pyridodiazaphosphorinones 5–7, which, upon reaction with bis-(2-chloroethyl) ammonium chloride/triethylamine, were converted into the P-bis-(2-chloroethyl)amino-substituted pyridodiazaphosphorinones 8–10. The P-chloro-benzodiazaphosphorinone 11 was allowed to react with 2-chloroethylammonium chloride/triethylamine to form the 2-chloroethylamino-substituted derivative 12. The σ3-diazaphosphorinones 8, 9, 12 and 13 were oxidized with the urea-hydrogen peroxide-(1 : 1)-adduct to the corresponding phosphoryl derivatives 14–17. The oxidative addition of hexafluoroacetone (HFA) to the σ3-diazaphosphorinone 18 led, with abstraction of methyl chloride, to the tricyclic phosphorane 19 b. The spirophosphoranes 21–23 were formed by reaction of compounds 8, 9 and 13 with HFA. NMR-studies were made on the decomposition of the bicyclic phosphoranes 20 a, 22 and 23. The oxidative addition of HFA to diazaphosphorinones was found to be reversible. Single crystal X-ray determinations were conducted on compounds 17 and 19 b. They confirm the expected connectivity. Compound 17 was found to exhibit short C–H‥ O-hydrogen bonds (H…O 234 pm). Compound 19 crystallises as two independent molecules which differ, e. g., in the orientation of the chloroethyl groups.

BEITRÄGE ZUR CHEMIE VON VINYLPHOSPHONSÄUREDERIVATEN

Abstract Vinylphosphonsäuredichlorid I sowie dessen Thioanalogon 3 wurden mit Dialkylaminotrimethylsilanen Me3SiNR2 (R = Me. Et) zu den entsprechenden Amidchloriden CH2=CHP(:O)CI(NR2) 5 (R = Me) und 6 (R = Et) sowie den Thioamidchloriden CH2=CHP(:S)CI(NR2) 7 (R = Me) und 23 (R = Et) umgesetzt. Analoge Alkoholysereaktionen lieferten die ethoxy- und phenoxysubstituierten Esterchloride CH2=CHP(:O)CI(OR) 10 (R = Et) und 12 (R = Ph); außerdem erhält man durch Veresterung mil aromatischen Diolen wie Tetrachlorbrenzkatechin oder 1,2-Dihydroxynaphthalin Diester. Sowohl die erwähnten Amidchloride ah auch die Ehterchloride wurden in einem weiteren Schritt durch Chlor-Fluo-raustausch mit SbF3 bzw. AsF3 in die entsprechenden Amidfluoride bzw. Thioamidfluoride CH2=CHP(:X)F(NMe2) 8 (X = O) bzw. 9 (X = S) und die Esterfluoride CH2=CHP(:O)F(OR) 11 (R = Et) bzw. 14 (R = Ph) überführt. Schließlich wurden weitere Vinylphosphonsäurederivate, wie z.B. die vinylsubstituierte, cyclophosphamid-analoge Verbindung 21 durch Amino-lyse- und Alkoholysereaktionen synthetisiert. Von Verbindungen 12, 17 (als Dichlormethansolvat) und 19 wurde Röntgenstrukturanalysen durchgeführt. In 12 ist die Koordination am Phosphor erwartungsgemäß verzerrt tetraedrisch, in 17 quadratisch pyramidal; das Dichlormethanmolekül ist an einer kurzen nicht-klassischen Wasserstoffbrücke C-H…O beteiligt. Verbindung 19 weist kristallographische Spiegel-symmetrie auf.

SYNTHESE SYMMETRISCHER, MAKROCYCLISCHER PHOSPHORAMIDITE

Abstract The reaction of phosphorous ester diamide 1 with bisphenol 2 did not lead to the expected asymmetric macrocycle 3 but instead in low yield to the symmetric macrocycle 4. The structure of the trans-isomer of 4 was determined by X-ray diffractometry. The same phenomenon was observed in the reaction of phosphorous ester diamide 5 with bisphenol 6, affording the symmetric macrocycle 7 as a mixture of cis-and trans-isomers. These results can only be explained by transesterification reactions which occur prior to the esterification of the phosphorous amide function.

1,8-Bis(dimethylphosphino)naphthalene: an Unusual Case of Pseudosymmetry

The title compound, C 14 H 18 P 2 , crystallizes in the rare tetragonal space group P4 2 bc with two independent molecules, each of which displays crystallographic twofold symmetry. In both molecules, the proximity of the PMe 2 groups leads to distortion, the main feature of which is the out-of-plane displacement of the P atom [by 0.378(5) and 0.297(6)A]. The structure displays a marked pseudosymmetry, with local inversion centres each relating four pairs of molecules.

Synthesis of Stable N,N,N,N-Tetramethylguanidine-Substituted σ4(P)- and σ3(P)-Organophosphorus Compounds with N-Protonated P–N Bonds - The First σ3-Phosphorus-Substituted Ammonium Salts

The dependence of the protolytic decomposition rate of phosphorus amides on the substituents at phosphorus is decribed. On treatment with HCl, the N′,N′,N′′,N′′-tetramethylguanidine(= TMG)-substituted σ4(P) compounds 5 and 9 formed salts that were protonated at the imino nitrogen atoms and were completely stable in the solid state, and surprisingly stable in solution. Even with a large excess of HCl, only the imino nitrogen atom underwent protonation, with formation of HCl2– as a counter anion, without cleavage of the P–N bond. The basicity of the imino nitrogen atom also protected σ3(P) species from electrophilic attack, and the ionic compounds 12, 14, and 20c were formed, providing examples of the first stable σ3(P) amides with one or two protonated P–N bonds. Such unusual stability is associated with steric protection by the Ph3C (= trityl) group and charge delocalization over the TMG-moiety. In contrast, MeP(TMG)2 was unstable towards HCl, whereas treatment with HSbF6 led to the phosphonium salt 24, where protonation had occurred at phosphorus. The same result was obtained when triphenylmethylphosphonous dichloride 1 was allowed to react with 3 equivalents of HTMG, forming the stable phosphonium salt 19, soluble in water, which was converted to the bicationic species 20c upon treatment with HCl. – The basicity of the tritylated phosphorus compounds was found to increase in the order 5 < 2 < 19 < 13 HTMG < 21; the basic centre is the phosphorus atom in 21 and the imino nitrogen atom in all other compounds. The fluorinating agent Et3N · 3 HF caused rapid conversion of compound 6to 25, the nucleophilic attack of fluoride ion at phosphorus could not be prevented by the stabilizing effects mentioned. – All compounds were investigated by 1H- and 31P-NMR spectroscopy. The crystal structures of compounds 5, Ph3CP(=O)-(H)TMG, and 6, [5 · 2 HCl], were determined; 6 is protonated at the imino nitrogen, leading to a longer P–N bond [5: 161.6(2), 6: 168.7(2) pm], and the counterion is HCl2–. In the structure of 20c, [Ph3CP(TMG)2] · 3 HCl, the cation is protonated at both imino N atoms and the counterions are Cl– and HCl2– (one of each).

Röntgenstrukturanalytische Untersuchungen von Diazadiphosphetidinen

Verschiedene Diazadiphosphetidine werden aus PCl5 und primaren Aminen, entsprechend einer modifizierten Kirsanov-Reaktion, hergestellt und einer Rontgenstrukturanalyse unterzogen. Die Ergebnisse der Rontgenstrukturanalysen der Hexahalogendiazadiphosphetidine weisen auf eine sterische Hinderung in der cyclohexylsubstituierten Verbindung 4 hin. Im Vergleich zur Struktur der Fluorverbindung 12 wird gezeigt, das die sterische Hinderung nur bei Chlorphosphoranen eine Rolle spielt. Bei der Kirsanov-Reaktion von PCl5 mit aliphatischen Aminen, die in α-Stellung verzweigt sind, wurde eine Folgereaktion beobachtet, wenn das Amin im Uberschus eingesetzt wurde. Das Phosphonium-Salz 11 wird durch 1H-, 13C- und 31P-NMR-Spektren, FAB-Massenspektrum, Elementaranalyse und Rontgenstrukturanalyse zweifelsfrei charakterisiert. X-Ray Structure Analysis of Diazadiphosphetidines Various diazadiphosphetidines are synthesized by a modified Kirsanov reaction and subjected to X-ray crystal structure analysis, the results of which show steric hindrance in the cyclohexyl-substituted compound 4. A comparison of its structure to that of the fluorine compound 12 shows that the steric hindrance occurs only in the case of chlorophosphoranes. During the Kirsanov reaction with aliphatic amines branched at the α-position, a further reaction is observed if the amine is added in excess. The phosphonium salt 11 is characterized by 1H-, 13C- and 31P-NMR-spectra, FAB-mass spectrum, elemental analysis and X-ray crystal structure analysis.