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N,N',N'-[Tris(trimethylysilyl)]hydrazino-diphenylphosphane, (TMS)2N-(TMS)N-PPh2, and N,N',N'-[tris(trismethylsilyl]hydrazino-phenyl(chloro)phosphane, (TMS)2N-(TMS)N-P(Cl)Ph2, are obtained in the reaction of bis-[lithium-tris(trimethylsilyl)hydrazide] with Ph(sub n)PCl(sub 3-n) (n = 1,2). The structure and bonding of both species are discussed on the basis of experimentally observed and theoretically obtained data.

The [Me.sub.3]SiOTf-mediated condensation of 1-ethoxy-2-fluoro-1,3-bis(trimethylsilyloxy) 1,3-dienes with 3-cyanochromones to generate 3-cyano-2-(4-ethoxy-3-fluoro-2,4-dioxobutyl)chroman-4-ones is described. The product distribution in the reaction depends on the structure of the diene and the formation of the biaryls is demonstrated by an unprecedented domino 'retro-Michael/aldol/fragmentation' reaction.

The addition of alkali or silver salts of dicyananoamide (dca), tricyanomethanide (tcm) and tetracyanoborate (tcb) to a solution of B[([C.sub.6][F.sub.5]).sub.3] in diethyl ether has produced salts containing voluminous C[([C.sub.6][F.sub.5]).sub.3] adduct anions. The studies have shown that as counterions for cationic early transition metal catalysts, the anions have displayed reduced ion pairing and hence increased catalytic activity.

The reaction taking place during the Ga[Cl.sub.3]-assisted methyl/chlorine exchange in silylated hydrazinodichloroarsane is being explained. The reaction is proved to be extremely useful for the formation of triazadiphospholes.

The terminal phosphine groups at the tungsten bisphosphine alkyne complex [Tp*W(CO)(I)(η²-C,C'-Ph2PC2PPh2)] (2) {Tp* = hydridotris(3,4,5-trimethylpyrazolyl)borate} were selectively oxidized by common methods to form the alkyne complexes 2EE (E = O, S) with either two phosphine oxide or two phosphine sulfide substituents. The respective mono-oxidized analogues 2E (E = O, S) were obtained by subjecting the already oxidized intermediates [Tp*W(CO)(I)(η²-C,C'-Ph2P(E)C2H)] 1E (E = O, S) to a late-stage phosphine introduction at the complex template. These modulations of the peripheral alkyne moiety have a clear impact on the redox potential of the metal-based oxidation altering the W(II/III) potential by +0.1 V on average per oxidized phosphine. In contrast to the comparable redox behavior of 2O and 2S, the coordination behavior of these complex ligands differs substantially. XRD studies show that complex 2 and the sulfide 2Sact either as a P,P'- or P,S-chelate ligand leading to the dinuclear complexes [(2)PdCl2], 3, and [(2S)PdCl2], 3S. In contrast, the corresponding PdCl2 complex of the monoxide 2O is connected by the free phosphine group and the W-bonded iodide as a μ²-bridging ligand leaving the phosphine oxide pending. A similar binding mode was found for the trinuclear gold complex [(2)2Au][PF6] (5-PF6). Furthermore, these findings explain the undesired outcome in the reaction of [Pd(NCMe)4][BF4]2 with two equivalents of 2, which resulted in the iodide abstraction product [(2)PdI2] (4). [ABSTRACT FROM AUTHOR]

New eydie and acylic phosphorus--nitrogen compounds have been synthesized in reactions of Hyp--N(SiMe3)PCl2 (hypersilyl = Hyp = (Me3Si)3Si) with silver salts of the perfluorinated anions [CF3C02]-, [CF3S03]-, and [C6F5]-. Depending on the choice of the silver salt, not only AgCl but also Me3SiCl elimination could be observed, leading to a transient highly reactive 1,3 dipole molecule. This 1,3 dipole molecule was found to be a key species, which can undergo [3 + 2] cydization, when a dipolarophile such as acetonitrile is present Also, dimerization or even cyclo-tetramerization are observed. The occurrence of different reaction channels demonstrates that the hypersilyl moiety can act as a highly reactive functional group. All new compounds have been characterized by single-crystal X-ray diffraction studies. [ABSTRACT FROM AUTHOR]

The synthesis of 1,3-dichloro-cyclo-1,3-diphosphadiazanes [ClP(μ-NR)]2 via elimination of Me3SiCl from silylated amino(dichloro)phosphanes, R-N(SiMe3)PCl2, was studied by different synthetic protocols starting from R-N(H)SiMe3 (R = Si(SiMe3)3 = Hyp, N(SiMe3)2, Mes* = 2,4,6-tri-tert-butylphenyl, Ter = 2,4-bis(2,4,6-trimethylphenyl)phenyl, Dipp = 2,6-diisopropylphenyl, Dmp =2,6-dimethylphenyl, Ad = Adamantyl, Trityl = Ph3C, Tos = tosyl = CH3C6H4SO2, n-Oct = n-octyl, and Me3Si). A new synthetic route using trimethylsilyl-substituted amino(dichloro)phosphanes, R-N(SiMe3)PCl2, was developed to form cyclo-diphosph(III)-azanes simply by adding a mixture of RfOH/base (RfOH = hexafluoroisopropanole). By this method electron-rich/-poor aryl-, silyl-, and bissilylamino-substituted cyclo-diphosph(III)-azanes are accessible such as the unprecedented (Me3Si)2N-substituted species [ClP(μ-NN(SiMe3)2)]2 starting from tris(trimethylsilyl)hydrazine and PCl3. Additionally, the difficulties with the preparation of cyclo-diphosphadiazanes depending on the starting materials, solvents, and bases due to the competition of different reaction channels are studied. [ABSTRACT FROM AUTHOR]