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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 1739-1746 
    ISSN: 0009-2940
    Keywords: Nitrilimines ; Phosphorus heterocycles ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions involving the λ3-phosphorus atom of N-[bis(diisopropylamino)phosphanyl)]-C-[(bis(diisopropylamino) -thio-phosphoranyl)nitrilimine (1) are reported. Addition of elemental sulfur or selenium to 1 leads, by a formal [1 + 4] cycloaddition, to 1,3,4,2λ5-thiadiazaphosphole 3a or 1,3,4,2λ5-selenodiazaphosphole 3b in 85 and 84% yield, respectively. Reactions of 1 with dimethyl acetylenedicarboxylate and tetracyanoethylene afford the corresponding [2 + 4] adducts 1,2,3λ5-diazaphosphinine 6 (80% yield) and 1,2,4,3λ5-triazaphosphinine 10 (80% yield). Phenyl azide reacts with 1 with loss of nitrogen to give 1,2,4,3λ5-triazaphosphole 15 (74% yield), while the reaction of 1 with α-diazo ketone 17 leads with conservation of the N2 grouping to the formation of 1,2,4,3λ5-triazaphosphole 20 (85% yield). Addition of methyl trifluoromethanesulfonate to 1 affords N-[bis(diisopropylamino)methylphosphonioyl]-C-[bis(diisopropylamino)thiophosphoranyl]nitrilimine 22. In contrast to 1, the new stable nitrilimine 22 is strongly electrophilic. [2 + 3] cycloadditions are observed with ethyl vinyl ether, styrene, methyl acrylate and phenylacetylene to furnish the corresponding pyrazolines 23 - 25 and pyrazole 26 in good yields. Water adds to 22 by a 1,3-addition process to give hydrazine 27 (88% yield). The lithium salt 30 of [bis(diisopropyl-amino)thiophosphoranyl](diazo)methane reacts with [bis(pentafluorophenyl)](chloro)phosphane to afford the corresponding diazo compound 32 (50% yield) while the reaction with (chloro)(phenyl)[2,4,6-tris(trifluoromethyl)phenyl]phosphane furnishes nitrilimine 33 in 82% yield. Only 1,3-addition reactions with water or diisopropylamine leading to hydrazine 34 (65% yield) and hydrazone 35 (54% yield) are observed on treatment with this new poorly reactive nitrilimine.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 581-589 
    ISSN: 0009-2940
    Keywords: Silene, dichloroneopentyl- ; Imines ; Cycloaddition reactions ; 2-Silaazetidines ; Thermolysis reactions ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Silaheterocycles, XXIII[1]. - Synthesis and Thermolysis Reactions of Si-Functionalized 2-SilaazetidinesDichloroneopentylsilene (1) is formed in situ by the reaction of trichlorovinylsilane with LitBu. The [2 + 2] cycloaddition to imines yields Si, Si1-dichloro-functionalized 2-silaazetidines in a preparative scale. With aldimines as trapping agents for 1, the resulting SiN four-membered ring compounds are isolated as syn/anti1-isomers (e.g. syn/anti-15 and -16; syn/anti ≍ 2:1). Silene 1 is not liberated from the silaazetidines on heating, but the Si, Si1-dichloro-substituted silanimine Cl2Si=NtBu (24) is formed. This can be trapped by Me3SiOMe or Ph2C=NtBu to give the addition products 25 and 26, respectively. The pathways are discussed which lead to stereoisomeric SiN ring compounds by a multiple-step mechanism including zwitterionic intermediates (1,4-dipoles). In addition there is strong evidence for the formation of 1, depending on the trapping reagent used. This fact may be explained by donor→silene interactions. The thermolysis products of silaazetidines support the formulation of a stepwise decomposition to an alkene and Cl2Si=NR derivatives.
    Additional Material: 4 Tab.
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  • 3
    ISSN: 0947-6539
    Keywords: ab initio calculations ; cyclic ylides ; heterocycles ; phosphorus ylides ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A number of possible strategies for the preparation of λ5-phosphetes were tested as follows: cyclopropenium 6 was treated with the lithium salt of diphenylphosphine to give phosphinocyclopropene 7, but 7 did not undergo ring expansion upon photolysis or thermolysis. P-chloro-C—trimethylsilyl-substituted ylide 8b reacted with two equivalents of dimethyl acetylenedicarboxylate to afford phosphinine 13 via a transient λ5-phosphete 12. Addition of aluminum trichloride to P-halogenated ylides 17a-b led to dihydrophosphetium salts 19a-b, which, upon treatment with pyridine, isomerized into the 1, 2-dihydrophosphet-2-ium salts 20a-b. Hydrolysis of derivatives 20a-b cleanly afforded phosphoniums 21 a-b, which reacted with NaN(SiMe3)2 to give rise to the corresponding λ5-phosphetes 22a-b. The benzo-λ5-phosphete 22a underwent ring expansion reactions with dimethyl acetylenedicarboxylate and acetonitrile, leading to benzo-λ5-phosphinine and benzo-1, 4λ5-azaphosphinine in good yields. Derivative 22b was characterized by X-ray crystal structure analysis. Ab initio SCF calculations, IGLO-13C chemical shifts and Δχ for various benzannulated derivatives and phosphorus heterocycles are presented.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 1479-1488 
    ISSN: 1434-1948
    Keywords: Phosphorus heterocycles ; Cations ; Tungsten complexes ; Coordination modes ; Phosphaalkenes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 1,1,3-tris(diisopropylamino)diphosphirenium salt 1 reacts with lithium aluminium hydride leading to the P-hydrogeno-C-phosphinophosphaalkenes 2, which on treatment with a catalytic amount of BF3·OEt2 afford the 1,3-bis(diisopropylamino)-1H-diphosphirene 3. The corresponding η1-coordinated 1H-diphosphirene 6 can be prepared by treatment of 2 or 3 with one equivalent of [W(CO)5(thf)]. Alternatively, the diphosphirenium salt 1 reacts with an excess of [W(CO)5(thf)], affording the corresponding η1-coordinated diphosphirenium salt complex 4, which is converted into the P-hydrogenophosphaalkene complex 5 with lithium aluminium hydride. The dinuclear tungsten complexes 7 and 8 are obtained by treatment of the free 1H-diphosphirene 3 with two equivalents of [W(CO)5(thf)] or one equivalent of [W(CO)4(thf)2], respectively. Compound 6 reacts with two equivalents of hydrogen chloride, giving the 1-chloro-3-diisopropylamino-1H-diphosphirene 9, which can be subsequently converted into the 1-diisopropylamino-, 1-azido, or 1-phenyl-3-diisopropylamino-1H-diphosphirenes 6, 10 and 11 by nucleophilic substitution with diisopropylamine, azidotrimethylsilane or sodium tetraphenylborate, respectively. The [η2-(3-diisopropylaminodiphosphirenylium salt)·W(CO)5] complexes 12a-c can be prepared by reaction of 9 with silver trifluoromethanesulfonate, aluminium or gallium trichloride or, alternatively, by treatment of 6 with two equivalents of trifluoromethanesulfonic acid. Reaction of 12a with diisopropylamine, water, bis(triphenylphosphoranylidene)ammonium chloride or tetrabutylammonium fluoride gives the corresponding 1H-diphosphirene complexes 6, 13, 9, or 14, respectively. Compound 12a also reacts with one or two equivalents of [W(CO)5(thf)], leading to the di- and tri-nuclear complexes 15and 16, respectively.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 2295-2299 
    ISSN: 1434-1948
    Keywords: Lewis acids ; Bismuth ; Aluminum ; Phosphorus ; Tin ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The dilithium salts of N-methyl-N′,N′′-bis(diisopropyl)- and -(trimethylsilyl)-diethylenetriamine 1a,b react with SnCl2 affording the corresponding stannylenes 2a,b in 60 and 80% yield, respectively. Compound 1b also reacts with BiCl3 to give the bismuth chloride 5 (90% yield). Derivatives 2b and 5 have a symmetrical bicyclic structure and are monomeric both in solution and in the solid state. When 2b is treated with BiCl3 or PCl3, an oxidation reaction leads to the hypercoordinated tin(IV) dichloride 3 (58% yield), or a transmetallation gives rise to the oniophosphane 4 (95% yield), respectively. Transmetalation reactions also occurred when 5 was treated with AlCl3, GaCl3 or SnCl2 affording the corresponding aluminum chloride 6 (81% yield), gallium chloride 7 (38% yield) or tin dichloride 3 (38% yield). The observed reactivity for 2 and 5 is compared to that reported for Veith's stannylene or bismuth chloride.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 173-178 
    ISSN: 1434-1948
    Keywords: P Ligands ; N Ligands ; Copper ; Zinc ; Structure elucidation ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Lithiation of triphenyl(trimethylsilylimino)phosphorane Ph3P=NSiMe3 with MeLi gives the ortho-metallated species [Li(o-C6H4PPh2NSiMe3)]2·Et2O (1), which exhibits all the requirements of an organometallic ligand capable of side-arm donation. The deprotonated ortho-phenyl carbon atom gives access to metal-carbon σ bonds in transmetallation reactions, while the Ph2P=NSiMe3 moiety can donate to the same metal center through the imine nitrogen atom. In transmetallation reactions with CuBr, the dimeric organocopper complex [Cu(o-C6H4PPh2NSiMe3)]2 (2) is obtained, while application of ZnCl2 yields the monomeric zinc complex [Zn(o-C6H4PPh2NSiMe3)2] (3). Reaction with CuCl2 gives access to the new diiminophosphorane (o-C6H4PPh2NSiMe3)2 (4) through oxidative coupling at the ortho positions. In all the metal complexes, the Ph2P=NSiMe3 residue acts as a side-arm donating group through the nitrogen atom. The intermolecular N→Cu donor bond in 2 is as short as copper-amide bonds, while the N→Zn bond lengths in 3 are in the region normally found for donor bonds. Compound 4 is a molecule, possessing two Ph2P=NSiMe3 moieties bridged by a biphenylene group.
    Additional Material: 4 Ill.
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  • 7
    ISSN: 1434-1948
    Keywords: Palladium ; Carbenes ; Metallacycles ; 1,2,4-Triazole ; Coordination modes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mononuclear palladium carbene complexes 2a-c and 3 derived from 1,1′-methylenebis(4-alkyl-4,5-dihydro-1H-1,2,4-triazole-5-ylidene) have been obtained by the reaction of 1,1′-methylenebis(4-alkyl-1,2,4-triazolium) diiodides 1a-d with palladium acetate under mild conditions. The mononuclear complexes 2a-c have been transformed into their corresponding trans-binuclear complexes 4a-c. All compounds were characterized by spectroscopic techniques and the dynamic behavior of 2a-cand 4a-c has been studied. The X-ray structures of 2a and 4c are reported.
    Additional Material: 3 Ill.
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  • 8
    ISSN: 1434-1948
    Keywords: Carbenes ; Insertions ; Donor systems ; Phosphorus heterocycles ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bis(diisopropylamino)(trimethylstannyl)phosphane (2) reacts with the (chloromethylene)diisopropylammonium salt 1 affording the C-phosphanyl-substituted iminium salt 3 (67 % yield), which features a short C-N (1.284 Å) and a long P-C bond (1.850 Å), a planar iminium nitrogen atom and a pyramidalized phosphorus atom. Deprotonation of 3 leads to the enamine 8 (92 % yield), while addition of sodium methoxide followed by thermolysis of the resulting hemiaminal 9 (90 % yield) gives rise to the azaphosphetane 10 (85 % yield), by intramolecular CH insertion of the transiently formed (amino)(phosphanyl)carbene 6.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Heteroatom Chemistry 2 (1991), S. 29-38 
    ISSN: 1042-7163
    Keywords: Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermolysis of [bis(diisopropylamino)phosphanyl](trimethylsilyl)diazomethane 1 affords the corresponding carbene 2, which is stable enough to be spectroscopically characterized. This species possesses a phosphorus-carbon multiple-bond character as shown by the 2 + 3 and 2 + 2 cycloaddition reactions observed with trimethylsilyl azide or N2O and ethyl cyanoformate, respectively. On the other hand, 2 undergoes all the classical reactions of a carbene: cyclopropanation reaction with electron-poor alkenes, carbon-hydrogen bond insertion, and carbene-carbene coupling with isonitriles. Compound 2 reacts with trimethylsilyl triflate affording a stable methylenephosphonium salt 15. Treatment of the lithium salt of the [bis(diisopropylamino)thiophosphoranyl]diazomethane 18 with the bis(diisopropylamino)phosphanyl chloride leads to a stable nitrilimine 3. Thermolysis of 3 affords the isomeric diazo derivative 20, while photolysis gives rise to thiophophoranylnitrile 21 and cyclodiphosphazene 23. Regioselective 2 + 3 cycloadditions are observed with electron-poor dipolarophiles. Addition of trimethylsilyl triflate to 3 leads to a stable electrophilic nitrilimine 29.
    Additional Material: 1 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Heteroatom Chemistry 7 (1996), S. 403-408 
    ISSN: 1042-7163
    Keywords: Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tris(iminotriphenylphosphoranyl)phosphonium chloride2, tris(iminotriphenylphosphoranyl)phosphine 3, bis(iminotriphenylphosphoranyl)dichlorosilane 4, tris(iminotriphenylphosphoranyl)-chlorosilane 5 and -hydrogenosilane 6 have been prepared by reacting the iminotriphenylphosphorane1 with trichlorophosphine or the corresponding chlorosilanes. A multinuclear NMR study of these compounds is presented. © 1996 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
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