A convenient synthesis of 2‐(1H‐1,2,4‐triazol‐1‐yl)‐2H‐1,4‐benzothiazine derivatives

A series of 2‐(1H‐1,2,4‐triazol‐1‐yl)‐2H‐1,4‐benzothiazines were designed and synthesized by condensation of 1,2,4‐triazole‐substituted ω‐bromoacetophenones and o‐aminothiophenols with the aid of K₂CO₃ under mild conditions with moderate to high yields. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:332–336, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20434     

Palladium N‐heterocyclic‐carbene‐catalyzed ortho‐arylation of benzaldehyde derivatives

New, sterically demanding 1,3‐dialkylbenzimidazolium salts ( 2a–c ) as N‐heterocyclic‐carbene precursors have been synthesized and characterized. The ortho position of aromatic aldehydes was directly and selectively arylated with aryl chlorides in the presence of a catalytic system prepared in situ from Pd(OAc)₂, 1,3‐dialkylbenzimidazolium chlorides ( 2a–c ), and Cs₂CO₃. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:569–574, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20479     

Bismuth‐catalyzed cyclization of amino‐1,6‐enynes

Bi(OTf)₃ effectively catalyzed the cyclization of amino‐1,6‐enynes, leading to bicyclic amine and cyclopentadienyl amino compounds. The selectivity of the products depends on the substitution pattern of the olefinic moiety. ¹⁹F NMR trace experiment of the reaction and other results indicate a novel alkynophilicity of the bismuth species. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:644–648, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20490     

N‐functionalized azolin‐2‐ylidene‐palladium‐catalyzed heck reaction

Novel 1,3‐dialkylimidazolidinium, 1,3‐dialkyl‐3,4,5,6‐tetrahydropyrimidinium, and 1,3‐dialkyl‐1H‐4,5,6,7‐tetrahydrodiazepinium hexafluorophosphates ( 1a–c, 2a–c ) as N‐heterocyclic carbene precursors have been synthesized and characterized. The incorporation of saturated N‐heterocyclic carbenes into palladium precatalysts gives high‐catalyst activity in the Heck coupling of aryl bromide substrates in aqueous media. The complexes were generated in the presence of Pd(OAc)₂ by in situ deprotonation of 1,3‐dialkylazolinium salts 1, 2 . © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:82–86, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20415     

Synthesis and conformational analysis of a small meta‐cyclophane,bis(5‐carbomethoxy‐1,3‐phenylene)‐14‐crown‐4

A small cyclophane, bis(5‐carbometh‐oxy‐1,3‐phenylene)‐14‐crown‐4 (BCMP14C4, 3 ) and its diacid, bis(5‐carboxy‐1,3‐phenylene)‐14‐crown‐4 ( 4 ), were synthesized and characterized. The solid‐state molecular structures of 3 and 4 were determined by X‐ray crystallography as ladder or stepped conformations in which the two aromatic rings are antiparallel to each other without overlap and the ethylene tethers both take trans‐conformations. Diester 3 is formed in the lowest cyclization yield (under the same reaction conditions) and exhibits the highest melting point compared to its larger ring (20‐, 26‐ and 32‐membered) analogs. In CD₂Cl₂ solution, diester 3 exists predominantly as a nonplanar gauche–gauche structure as deduced by H NMR studies. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:48–54, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20393     

Synthesis and characterization of novel (9H‐fluoren‐9‐ylamino) carbonylaminomethylphosphonic acid

The new α‐aminophosphonic acids are synthesized, reacting (9H‐fluoren‐9‐yl)urea with formaldehyde and phosphorus trichloride. (9H‐Fluoren‐9‐yl)urea was prepared from spiro(fluoren‐9,4′‐imidazolidine)‐2′,5′‐dione by alkaline hydrolysis with Ba(OH)₂. The structure of the title compounds was proved by means of IR, ¹H, ¹³C, and ³¹P NMR spectroscopy. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:719–722, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20500     

Syntheses and crystal structures of triorganotin(IV) complexes of schiff base derived from 4‐amino‐5‐phenyl‐4H‐1,2,4‐trizole‐3‐thiol

Four triorganotin complexes of the types [(Ph₃Sn)(C₁₅H₁₀FN₄S)] ( 3 ), [(CH₃)₃Sn(C₁₅H₁₀FN₄S)]_n ( 4 ), [(Ph₃Sn)(C₁₃H₉FN₄S₂)] ( 5 ), and [(CH₃)₃Sn(C₁₃H₉FN₄S₂)]_n ( 6 ) have been obtained by Schiff base compound 1 (derived from 4‐fluorobenzaldehyde) and compound 2 (derived from thiophene‐2‐carboxadehyde) with triorganotin chloride in the presence of sodium ethoxide. All the complexes were characterized by elemental analysis, IR, and NMR spectroscopies, and X‐ray diffraction analyses, which revealed that complexes 3 and 5 are mononuclear structures, complex 4 and 6 are one‐dimensional zigzag infinite chains via N → Sn and S → Sn bonding interactions. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:583–591, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20481     

Palladium‐catalyzed Heck coupling of 2‐vinylpyridine with aryl chlorides

An efficient PdCl₂(PCy₃)₂‐catalyzed cross‐coupling reaction of 2‐vinylpyridine with aryl chlorides to afford trans ‐2‐styrylpyridines with a variety of functional groups on the benzene ring is described. Copyright © 2008 John Wiley & Sons, Ltd.     

MnCl2‐Promoted synthesis of quinoxaline derivatives at room temperature

MnCl₂ efficiently catalyzes the condensation of o‐phenylenediamine derivatives with 1,2‐diketones at room temperature to afford the corresponding quinoxaline derivatives in high yields. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:218–220, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20401     

N → C2 → C3 migration of the dichlorophosphino group in the synthesis of phosphorylated NH‐pyrroles

A successive N → C₂ → C₃ migration of the dichlorophosphino group has been found to occur in phosphorylation of unsubstituted pyrrole with phosphorus trichloride. As a result of this migration, a number of hitherto unknown C‐phosphorylated N‐unsubstituted pyrroles have been obtained. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:671–676, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20495     

Microwave‐assisted ring‐opening polymerization of p‐dioxanone

The ring‐opening polymerization (ROP) of p‐dioxanone (PDO) under microwave irradiation with triethylaluminum (AlEt₃) or tin powder as catalyst was investigated. When the ROP of PDO was catalyzed by AlEt₃, the viscosity‐average molecular weight (M_v) of poly(p‐dioxanone) (PPDO) reached 317,000 g mol^?1 only in 30 min, and the yield of PPDO achieved 96.0% at 80 °C. Tin powder was successfully used as catalyst for synthesizing PPDO by microwave heating, and PPDO with M_v of 106,000 g mol^?1 was obtained at 100 °C in 210 min. Microwave heating accelerated the ROP of PDO catalyzed by AlEt₃ or tin powder, compared with the conventional heating method. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3207–3213, 2008     

Interactions of metal‐encapsulated fullerenes with solvents

The present investigation reports on the interaction of M@C₆₀(M = Be, Mg, Ca) with solvents (H₂O, CH₃OH, HF, NH₃) using Density Functional Theory calculations. Our computations reveal that the interaction of the fullerene species increases when endohedral metal atoms are inserted into its cavity. The most profound interaction of the fullerene systems is with water and hydrogen fluoride. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008     

Efficient synthesis of 2‐substituted thieno[2,3‐d]pyrimidin‐4(3H)‐ones via an iminophosphorane

The carbodiimides 4 , obtained from reactions of iminophosphorane 3 with aromatic isocyanates, were reacted with secondary amines to give 2‐dialkylamino‐5‐ethyl‐6‐methyl‐thieno[2,3‐d]pyrimidin‐4(3H)‐ones 6 in the presence of catalytic amount of EtONa. Reactions of 4 with phenols or ROH in the presence of the catalytic amount of K2CO₃ or RONa gave 2‐aryloxy‐ or 2‐alkoxy‐5‐ethyl‐6‐methyl‐thieno[2,3‐d]pyrimidin‐4(3H)‐ones 6 in satisfactory yields. The effects of the nucleophiles on cyclization have been investigated. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:266–270, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20424     

Highly soluble green‐emitting Ir(III) complexes with 9‐(6‐phenyl‐pyridin‐3‐ylmethyl)‐9H‐carbazole ligands and their application to polymer light‐emitting diodes

Highly organic soluble Ir(III) complexes with 9‐(6‐phenyl‐pyridin‐3‐ylmethyl)‐9H‐carbazole were simply synthesized, and the solubility of the new complex was significantly improved when compared with the conventional green‐emitting Ir(ppy)₃. Since a carbazole group is tethered through a nonconjugated methylene spacer, the photophysical properties of new complexes are almost identical with those of conventional Ir(ppy)₃. The pure complexes were utilized to prepare electrophosphorescent polymer light‐emitting diodes (PLEDs). The device performances were observed to be relatively better or comparable with those of Ir(ppy)₃ based poly(N‐vinylcarbazole) systems. The integration of rigid hole‐transporting carbazole and phosphorescent complex provides a new route to design highly efficient solution‐processable complex for electrophosphorescent PLED applications. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7419–7428, 2008     

Synthesis,characterization, and fluorescence phenomena of 1‐naphthoxy and 1‐naphthylamino substituted cyclotriphosphazenes

The reactions of hexachlorocyclotriphosphazene N₃P₃Cl₆ ( 1 ) with 1‐naphthol and 1‐naphthylamine have been examined. The reaction of 1 with sodium 1‐naphthoxy gave the hexakis(1‐naphthoxy)cyclotriphosphazene ( 2 ) in high yield. Geminal 2,2‐di(1‐naphthylamino)‐4,4,6,6‐tetrachlorocyclotriphosphazene ( 3 ) was obtained from the reaction of 1 with 1‐naphthylamine. The structures of phosphazene derivatives were defined by elemental analysis, FTIR, UV‐‐visible, and ¹H, ¹³C, ³¹P NMR spectroscopy. The fluorescence intensity of the compounds was measured in THF and CH₂Cl₂. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:158–162, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20400     

Ring‐opening polymerization of 1,4‐dioxan‐2‐one initiated by lanthanum isopropoxide in bulk

Lanthanum isopropoxide (La(OiPr)₃) has been synthesized and employed for ring‐opening polymerization of 1,4‐dioxan‐2‐one in bulk as a single‐component initiator. The influences of reaction conditions such as initiator concentration, reaction time, and reaction temperature on the polymerization were investigated. The kinetics indicated that the polymerization is first‐order with respect to the monomer concentration. The Mechanistic investigations according to ¹H NMR spectrum analysis demonstrated that the polymerization of PDO proceeded through a coordination‐insertion mechanism with a rupture of the acyl‐oxygen bond of the monomer rather than the alkyl‐oxygen bond cleavage. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5214–5222, 2008     

Inter‐diffusion effects in as‐deposited Al/Ni polycrystalline multi‐layers

Al/Ni multi‐layers, deposited by magnetron sputtering at room temperature have been studied by complementary techniques; XPS, sputter depth profiling, electron‐induced X‐ray emission spectroscopy (XES) and X‐ray diffraction (XRD). XPS depth profile technique evidenced an atomic diffusion dominated by Ni atoms. Moreover, the Ni diffusion results in the formation of an amorphous phase with a stoichiometry close to the Al₃Ni aluminide. Copyright © 2008 John Wiley & Sons, Ltd.     

Cobalt(II) chloride as a novel and efficient catalyst for the synthesis of 1,2,5‐trisubstituted pyrroles under solvent‐free conditions

CoCl₂ is used as an efficient catalyst in the Paal–Knorr condensation of 2,5‐hexadione with primary amines under solvent‐free conditions, leading to the formation of pyrrole derivatives in excellent yield. This method is very easy, rapid, and high yielding reaction for the synthesis N‐substituted pyrrole derivatives. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:592–595, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20482     

Rh‐ and Pt‐catalyzed cycloisomerization of enynes derived from terpenes

The Rh‐catalyzed cycloisomerization of new terpenoid derivatives featuring an O‐tethered enyne unexpectedly leads to polycyclic derivatives containing an inner cyclopropane ring or a diene moiety, depending on the structure of the enyne, as observed in the PtCl₂‐catalyzed processes. Copyright © 2008 John Wiley & Sons, Ltd.     

Synthesis and structural consideration of 1‐chloro‐N,N′,N″‐tris(pentafluorophenyl)azagermatrane: Azagermatrane with the shortest intramolecular N → Ge bond

Two compounds of a novel‐type azagermatrane, N(CH₂CH₂NC₆F₅)₃Ge‐Hal: HalCl ( 1 ), Br ( 2 ), were prepared via a metathetical reaction of trilithium salt of tetramine, N[CH₂CH₂N(Li)C₆F₅]₃, with corresponding GeHal₄. A single crystal structure of 1 was determined by the X‐ray diffraction study: The compound shows the strongest transannular N_ax → Ge interaction (2.148(7) Å) among other studied azagermatranes. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:738–741, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20476