Synthesis and structure of complexes of phosphorus pentachloride with 4‐dimethylaminopyridine and n‐methylimidazole

Complexes of phosphorus pentachloride with 4‐dimethylaminopyridine and N‐methylimidazole were synthesized. The molecular structure of the phosphorus pentachloride complex with N‐methylimidazole was determined by single‐crystal X‐ray diffraction. In the cationic part of the complex, the phosphorus atom possesses four P Cl bonds within the range 2.109–2.148 Å and two cis‐P–N bonds (1.811 and 1.832 Å) with N‐methylimidazole and exhibits slightly distorted octahedral coordination with angles at phosphorus atom in the range 87.57°–91.50°. The relative stability of the cis and trans conformations of the complex was studied by DFT calculations. The chemical properties and reactivity of the compounds obtained are determined; their utility as condensing agents in the synthesis of amides from acids and amines was shown. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:171–177, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20392     

A novel stereoselective synthesis of (2Z)‐2‐arylsulfanylallylic alcohols by tin–lithium exchange of (E)‐α‐stannylvinyl sulfides

Tin–lithium exchange reaction of (E)‐α‐stannylvinyl sulfides 1 with n‐butyllithium gave (Z)‐α‐arylsulfanylvinyllithiums 2 , which reacted with aldehydes or ketones 3 to afford stereoselectively (2Z)‐2‐arylsulfanylallylic alcohols 4 in good to high yields. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:639–643, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20487     

Synthesis and characterization of magnetoelectric polymer nanocomposites

Magnetoelectric polymer nanocomposite structures are synthesized using conducting polyaniline and nanosized BFO particles through in situ sol–gel polymerization. The effect of nanosized BFO in polyaniline matrix is studied. The SEM, XRD, VSM, FTIR, and UV–Vis studies were made to understand the morphology, crystalline structure, magnetic, and optical properties of PANI/BFO composites with various concentrations of nanofiller. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2418–2422, 2008     

Kaolin: A recyclable catalyst for the synthesis of 1,5‐benzodiazepines

2,3‐Dihydro‐1H‐1,5‐benzodiazepines are synthesized by the condensation of o‐phenylenediamine and various ketones in the presence of kaolin as a recyclable catalyst in dichloroethane. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:215–217, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20354     

A convenient synthesis of oxazolidinone derivatives linezolid and eperezolid from (S)‐glyceraldehyde acetonide

A new convenient method for the synthesis of oxazolidinone antibacterials Linezolid and Eperezolid from readily available (S)‐glyceraldehyde acetonide was developed. The key steps include reductive amination of arylamine and (S)‐glyceraldehyde acetonide in the presence of NaBH₄ and 4 Å sieve, followed by hydrolysis and regioselective cyclization. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:316–319, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20435     

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     

A facile and convenient synthesis of tetrasubstituted N‐hydroxypyrroles via intramolecular wittig reaction

Treatment of triphenylphosphine with dialkyl acetylenedicarboxylate leads to 1:1 adduct and concomitant protonation of late adduct by pentan‐2,3,4‐trione 3‐oxime gave the reactive intermediate, vinyltriphenylphosphonium salts, which undergoes an intramolecular Wittig reaction to produce tetrasubstituted N‐hydroxypyrroles in fairly high yields. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:100–103, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20382     

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     

Phosphorylation of N‐Silylpyrroles with Phosphorus Tribromide

Phosphorylation of N‐trimethylsilyl‐ and N‐dimethyl‐tert‐butylsilylpyrroles with phosphorus tribromide in pyridine proceeds selectively at position 3 of the pyrrole ring. Removal of the trialkylsilyl protecting group has furnished the first representatives of N‐unsubstituted 3‐phosphorylated pyrroles. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:93–96, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20416     

Oxidation using activated carbon and molecular oxygen system

This paper describes the utility of an activated carbon–molecular oxygen system, not only in the oxidation of benzylic and allylic alcohols, but also in the direct carbonylation at the benzylic position. The preparation of a variety of heteroaromatic and aromatic compounds, including substituted pyridines, pyrazoles, benzoxazoles, benzimidazoles, benzothiazoles, 2‐substituted imidazoles, indoles, pyrimidin‐2(1H)‐ones, and anthracenes, by oxidative aromatization using the activated carbon–molecular oxygen system is also discussed. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 252–267; 2008: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.20152     

A new class of sulfur‐linked bis‐1,2,3‐selenadiazoles, 1,2,3‐thiadiazoles,and 2H‐diazaphospholes

Novel sulfur‐linked bis‐heterocycles, bis‐1,2,3‐selenadiazoles 4 , 1,2,3‐thiadiazoles 5 , and 2H‐diazaphospholes 7 , were synthesized from bis(2‐oxo‐2‐phenylethanone)sulfide 2 by adopting a simple and well‐versed methodology. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:261–265, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20425     

An efficient and green method for the synthesis of N‐phosphoramino o‐hydroxylphenyl α‐aminophosphonic monoesters

An efficient and green method to the synthesis of N‐protected o‐hydroxylphenyl α‐amino‐alkylphosphonic monoesters is described. It consists of the three‐component Mannich‐type reaction of phosphoramides, carbonyl compounds (aldehydes or ketones), and 2‐chlorobenzo[1,3,2] diox‐aphospholes under solvent‐free and catalyst‐free conditions, followed by hydrolysis. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:596–601, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20483     

Synthesis of Organophosphorus‐Substituted Amides of Carbonic Acids with PCHNC(O) and 2,6‐Di‐tert‐butyl‐4‐methylphenol Fragments

Convenient procedures for the synthesis of new organophosphorus‐substituted amides of various carbonic acids with PCHNC(O) and 2,6‐di‐tert‐butyl‐4‐methylphenol (ionol) fragments, starting from the adducts of imines and acyl chlorides, are proposed. Some properties of the new synthesized organophosphorus amides are presented. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:733–737, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20502     

Preparative conversion of chloralamides to 2,5‐diaryl‐3a,6a‐dihydro‐[1,3]thiazolo[4,5‐d][1,3]thiazoles with the Lawesson reagent

Based on readily available chloralamides, a preparative method for the synthesis of hitherto unknown 2,5‐diaryl‐3a,6a‐dihydro[1,3]thiazolo[4,5‐d][1,3]thiazoles with the Lawesson reagent has been elaborated. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:677–681, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20493     

Synthesis and fungicidal activity of O‐alkyl O‐aryl O‐2‐(stearamido)ethyl phosphates

N‐stearoylethanolamine (NAE18:0) was reacted with O‐alkyl O‐aryl chlorophosphate and a series of O‐alkyl O‐aryl O‐2‐(stearamido)ethyl phosphates were synthesized to explore their antifungal activity. Compared with parent NAE18:0, title compounds without substitution or with methyl substitution on a benzene ring exhibited improved antifungal activity. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:602–608, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20485     

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     

Synthesis of cyclic aminomethylphosphonates and aminomethyl‐arylphosphinic acids by an efficient microwave‐mediated phospha‐mannich approach

Microwave‐assisted condensation of 1,3,‐2‐dioxaphosphinane 2‐oxide ( 1 ), paraformaldehyde and secondary amines including 5‐ and 6‐membered N‐heterocycles at 55°C gave cyclic aminomethylphosphonates ( 2 ), whereas an analogous reaction involving dibenzo[c.e][1,2]oxaphosphinane 2‐oxide ( 3 ) resulted in the corresponding aminomethyl‐2‐(2′‐hydroxybiphenyl)phosphinic acids ( 4 ) as a consequence of a hydrolytic ring opening following the condensation. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:207–210, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20387     

Stereoselective synthesis of trisubstituted alkenes containing (Z)‐allylthio units from the acetates of Baylis–Hillman adducts

A series of trisubstituted alkenes containing (Z)‐allylthio moieties as key structural units, that is, sodium (Z)‐allyl thiosulfates, symmetrical di(Z‐allyl) sulfides, and di(Z‐allyl) disulfides, unsymmetrical diallyl sulfides were prepared in moderate to good yields via chemical transformations from the acetates of Baylis‐‐Hillman adducts. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:188–198, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20394     

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     

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