The reactions of hexachlorocyclotriphosphazatriene with pyridine derivatives

The reactions of hexachlorocyclotripho‐sphazatriene, N₃P₃Cl₆ ( 1 ), with 2‐hydroxypyridine ( 2 ), 2‐aminopyridine ( 3 ), 2‐amino‐6‐methyl‐pyridine ( 4 ), and 2‐hydroxy‐4‐methylquinoline ( 5 ) have been investigated. The products were identified by elemental analyses, IR, ¹H, ¹³C, and ³¹P NMR spectroscopy. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:57–60, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20185     

The reaction of hexachlorocyclotriphosphazatriene with P-aminophenol

The reaction of hexachlorocyclotriphosphazatriene (1) with p-aminophenol (2) produced two new products: the open chain compound N₃P₃Cl₅(NHC₆H₄OH) (3), and the bridged compound N₃P₃Cl₅(NHC₆H₄O)N₃P₃Cl₅(4). The compounds 3 and 4 were separated and characterized by elemental analysis, massspectrometry and NMR spectroscopy. The molecular structures of compounds 3 and 4 were determined by X-ray crystallography. Compound 3 is the first example of cyclotriphosphazene including (p-hydroxyphenyl) amino group and compound 4 was the first example of the N-substituted p-aminophenoxy group with cyclotriphosphazene.     

Polyamine-stabilized sodium aryloxides: simple initiators for the ring-opening polymerization of rac-lactide

Metalation of 2,4,6-tri(methyl)phenol ((Me)ArOH) and 2,6-di(tert-butyl)-4-methylphenol ((Bu)ArOH) with NaN(SiMe(3))(2) in toluene and in the presence of stoichiometric amounts of the polydentate amines N,N,N',N'-tetramethylethylenediamine (TMEDA) and N,N,N',N',N'-pentamethyldiethylenetriamine (PMDETA) affords three new sodium aryloxide complexes [Na(μ-OAr(Bu))(TMEDA)](2) (3), [Na(μ-OAr(Me))(PMDETA)](2) (4), and [Na(OAr(Bu))(PMDETA)] (5). Complexes 3 to 5 have been isolated as crystalline materials in reasonable yields and characterized in the solid state by X-ray crystallography and in solution by NMR spectroscopy. Complexes 3 to 5 and the related [tris(2-dimethylaminoethyl)amine] (Me(6)TREN) derivatives [Na(OAr(Me))(HOAr(Me))(Me(6)TREN)] (1) and [Na(OAr(Bu))(Me(6)TREN)] (2), recently prepared in our group, are shown to be active as initiators for the ring-opening polymerization (ROP) of rac-lactide with benzyl alcohol as a co-initiator. However, during the course of the polymerization reactions intrachain and stereorandom transesterification side-reactions were observed under some of the experimental conditions tested.     

Synthesis of two-coordinate iron aryloxides and their reactions with organic azide: Intramolecular C-H bond amination

The synthesis and reaction of homoleptic iron(II) complexes with 2,6-di-adamantyl-substituted aryloxides [OC₆H₂-2,6-Ad-4-R]⁻ ([OAr^AdR]⁻, Ad = adamantyl, R = Me, ⁱPr) are described. Monomeric two-coordinate iron aryloxides Fe(OAr^AdR)₂ (R = Me, 1; ⁱPr, 2) were synthesized by the reaction of Fe[N(SiMe₃)₂]₂ with 2 equiv of HOAr^AdR. Treatment of 1 and 2 with 1-azidoadamantane resulted in intramolecular insertion of an adamantyl nitrene into a methylene C-H bond of the aryloxide adamantyl substituent, yielding the corresponding amine-aryloxide complexes Fe(OAr^AdR)(OAr^AdR-NHAd) (R = Me, 3; ⁱPr, 4). Molecular structures of all these complexes are reported.     

Unusual behavior of methylidentriphenylphosphorane in reactions with seven-membered lactols

Methylidenetriphenylphosphorane in reactions with seven-membered lactols and their aluminates can act as a reducer converting them into the corresponding diols.     

Rational assembly of primitive cubic networks using hexameric stacks of sodium aryloxides as nodes

The two sodium aryloxide complexes [{(4-R-C6H4ONa)6 x (dioxane)3}infinity], where R = Et (1) or F (2), have been prepared and found to form three-dimensional cubic networks in the solid state. Each structure is similarly composed of dioxane-connected Na6O6 aggregates that act as octahedral nodes in directing the assembly process. Although the localized metrical parameters within the hexameric cages are similar to each other, as well as to those of the molecular analogue [(4-F-C6H4ONa)6 x (THF)8] (3), the gross architectures show significant variations. In particular, the smaller complex 2 ensures effective filling of space through transannular Na-F interaggregate interactions, resulting in substantial compression of the cubic framework.     

Oximes as intermediates or final products in reactions of nitroheteroarenes with nucleophiles in the presence of sodium methoxide‐methanol system

It has been shown that reactions of 4‐nitroimidazoles and some other nitroaromatic systems with phenyl‐acetonitrile in the presence of sodium methoxide in methanol lead to the reduction of the nitro to nitroso group and to the nucleophilic displacement of hydrogen atom at the ring by the respective carbanion followed by tautomerization of the nitroso compound to an oxime. Similar reactions of 4‐nitroimidazoles with such nucleophiles as anions generated from 4‐amino‐1,2,4‐triazole occur with the ring transformation of imidazole into 1,2,4‐oxadiazole derivatives sometimes undergoing further processes in the reaction medium. Structures of some products have been confirmed by X‐ray diffraction analysis.     

Unusual reactions of isolable dialkylgermylene and -stannylene with galvinoxyl radical

The reactions of isolable dialkylgermylene and -stannylene with a galvinoxyl radical were found to give rather unusual cyclic compounds in high yields via intermediate adduct radicals. The structures of the cyclic compounds were determined by X-ray crystallography. We propose a concerted cyclization mechanism in which the abstraction of a hydrogen atom from the tert-butyl group by the galvinoxyl radical is accompanied by the simultaneous attack of the germyl radical center to the tert-butyl carbon atom.     

Unusual features of ethylene copolymerization reactions with binary metallocene catalysts

Ethylene/1-hexene copolymers produced with MAO-activated binary metallocene catalysts, such as combinations Cp₂ZrCl₂ + (Me₅Cp)₂ZrCl₂, (Ind-H₄)₂ZrCl₂ + (Me₅Cp)₂ZrCl₂, Cp₂ZrCl₂ + Cp₂TiCl₂, etc., contain three types of components. Two of the components can be attributed to active centers derived from each individual metallocene complex, and one or two materials are produced with different types of active center. Some of the binary catalysts generate the three components in comparable proportions, whereas other catalysts produce copolymers with one dominant component, which does not resemble the copolymers produced with the individual complexes. A mechanism is proposed for the formation of the “new” copolymer materials.     

The reactions of pyranylidenemethylpyrylium salts with sodium sulfide

Symmetrical pyranylidenemethylpyrylium salts react with sodium sulfide to give, after acidification, pyranylidenemethylthiapyrylium salts. In the case of unsymmetrical salts in which the methylene group is joined at the 2-position of one ring and the 4-position of the other, the ortho oxygen atom is displaced by sulfur. An unsymmetrical dye which is substituted in the 2,6-positions of one ring with phenyl groups and with alkyl groups in the other ring gave a product which contained the sulfur atom in the aryl-substituted ring.