A novel stereoselective synthesis of (Z)‐α‐arylsulfanyl‐α,β‐unsaturated ketones via Stille coupling of (E)‐α‐arylsulfanylvinylstannanes with acyl halides

(E)‐α‐Arylsulfanylvinylstannanes react with acyl halides in the presence of a catalytic amount of Pd(PPh₃)₄ and CuI cocatalyst to give stereoselectively the corresponding (Z)‐α‐arylsulfanyl‐α,β‐unsaturated ketones in good yields. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:218–223, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20536     

Thiiranation of 2′‐adamantylidene‐9‐benzonorbornenylidene using 4,4′‐oligothiodimorpholine and brønsted acid

On leaving 4,4′‐dithiodimorpholine 6 powder undisturbed at room temperature over 10 years, it led to the formation of 4,4′‐tetrathiodimorpholine 7 . Reactions of 2′‐adamantylidene‐9‐benzonorbornenyidene 1 with 6, 7 , and 4,4′‐thiodimorpholine 8 and a Brønsted acid in CH₂Cl₂ at room temperature proceeded to afford the corresponding thiiranes, 2 and 3 . The order of reactivity of 4,4′‐oligothiodimorpholines combined with a Brønsted acid is 7 > 6 > 8 . The thiirane 3 was transformed to 1 and 2 under the reaction conditions. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:12–18, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20505     

Reactions of 9,9′‐bibenzonorbornenylidene sulfoxides with TMSOTf: Anomalous pinacol‐type rearrangement of thiirane 1‐Oxides

syn‐9,9′‐Bibenzonorbornenylidene sulfoxide 8b underwent pinacol‐type rearrangement to form 9 , together with a mixture of thiiranes 4a and 4b by reaction with TMSOTf in CH₂Cl₂ at room temperature. The rearrangement of anti‐sulfoxide 8a proceeded more slowly giving a mixture of 9, 4a , and 4b . © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:29–34, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20507     

Indium trichloride–catalyzed synthesis of some novel 2,2′‐(N,N′‐diarylamino)‐ 4,4′‐diaryl‐5,5′‐arylidenebisthiazoles and their insecticidal activity

A series of novel 2,2′‐(N,N′‐diarylamino)‐4,4′‐diaryl‐5,5′‐arylidene‐bisthiazoles 2 were rapidly and smoothly prepared in good yields by using non conventional techniques i.e. microwave or ultrasonic irradiation, through indium trichloride catalyzed electrophilic substitution reaction of 2‐(N‐arylamino)‐4‐arylthiazoles 1 with various arylaldehydes. All the synthesized compounds were characterized on the basis of their elemental analyses and spectral data (IR, PMR and Mass). The synthesized compounds were also evaluated for their insecticidal activity against Helicoverpa armigera and gave promising results. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:224–231, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20537     

5‐phosphorylated 1,2‐disubstituted imidazoles

1,2‐Disubstituted imidazoles react with phosphorus(III) halides in pyridine regioselectively at position 5. The reaction proceeds the more readily, the higher the electron‐donating ability of the 2‐substituent in the starting imidazole. Hitherto unknown dihalo(imidazol‐5‐yl)phosphines have been obtained, and their properties have been studied. Also synthetic methods for the preparation of various monohalo(organyl)(imidazolyl)phosphines have been developed. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:289–308, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20550     

Contributions to the chemistry of 3‐cyanoacetylhydrazono‐2‐indolinones and X‐ray structure of Z‐3‐cyanoacetylhydrazono‐2‐indolinone monohydrate

The tendency of acylhydrazones to undergo a spontaneous cyclization into 1,3,4‐oxadiazolines has been investigated. Contrary to the literature data, an attempted transformation of isatin cyanoacetylhydrazone in solution generates stereoisomers and not the reported structural isomer oxadiazoline. A similar behavior of the corresponding l‐methyl‐ and l‐acetylisatin derivatives even under acetylation conditions has been found. The crystal structure of the Z isomer of 3‐cyanoacetylhydrazono‐2‐indolinone monohydrate is reported. It contains strong intramolecular hydrogen bond between the hydrazone N H and oxygen atom of the indolinone carbonyl, and in this way the Z isomer over the CN bond is stabilized. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:183–193, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20531     

Phosphorylation of derivatives of β‐dialkyaminocrotonitriles with phosphorus(III) halides

The reaction of β‐dialkylaminocrotontriles with phosphorus(III) halides has been investigated. The basicity of the dialkylamino group influences the phosphorylation markedly, with pyrrolidine being the amine of choice. It was found that a solvent and the ratio of triethylamine play a significant role in phosphorylation. Although chloro‐ and dichlorophosphine derivatives proved impossible to separate as individual compounds; their solutions can be successfully used for further transformations. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:194–201, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20532     

Tautomerism of 3‐nitro‐1,2,4‐triazole‐5‐one radical anions

The non‐degenerate tautomers of 3‐nitro‐1,2,4‐triazole‐5‐one (NTO) radical anions were investigated for the first time by an ESR method during electrochemical reduction of NTO in an aprotic medium. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis of α‐phosphonylated phosphonium and sulfonium ylides: Study of their thermal behavior

The additions of two equivalents of trialkylphosphites onto phosphonodithioformates produce stabilized α‐sulfanyl‐α‐phosphonyl phosphonium ylides. Their subsequent reaction with alkyl or benzyl halides gives stabilized sulfonium ylides. Thermal treatment of these phosphonium and sulfonium ylides leads to α‐sulfanyl methylene bis‐phosphonates through protonation–dealkylation intramolecular reactions. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:164–171, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20530     

Highly selective synthesis of 1‐phenylpentane‐1, 4‐diones,and (E)‐5‐hydroxy‐5‐phenylpent‐3‐en‐2‐ones catalyzed by organophosphorus compounds

1‐Phenylpentane‐1, 4‐diones, and (E)‐5‐hydroxy‐5‐phenylpent‐3‐en‐2‐ones were synthesized via organophosphine‐catalyzed addition reaction of but‐3‐en‐2‐one with aldehydes. The features of the present protocols include high selectivity, operational simplicity, atom economy, and mild reaction conditions without transition metals. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 20:425–430, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20568     

Imidazolium‐based phosphinite ionic liquid as reusable catalyst and solvent for one‐pot synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ (thio)ones

A mild and efficient procedure for the synthesis of 3,4‐dihydropyrimidin‐2(1H)‐(thio)ones in phosphinite ionic liquid is described. This ionic liquid plays a dual role as both the reaction media and also a catalyst, which can be easily recovered and reused in several runs. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:284–288, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20549     

Synthesis of α‐hydroxy‐methylenebisphos‐phonates by the microwave‐assisted reaction of α‐oxophosphonates and dialkyl phosphites under solventless conditions

The synthesis of hydroxy‐methylenebisphosphonates ( 2a–c ) by the addition of dialkyl phosphite to the carbonyl group of the corresponding α‐oxophosphonate ( 1a–c ) was studied under microwave irradiation (MW) and solventless conditions in the presence of dialkylamine as the catalyst. After optimization, products 2a and 2b were obtained selectively and in good yields avoiding the formation of the phosphonate‐phosphate by‐product ( 3a and 3b ) that is the result of a rearrangement. The MW‐assisted synthesis of hydroxybisphosphonates ( 2a and 2b ) offers complete conversions and a chemoselectivity of 100% as compared to the not so efficient thermal reaction. At the same time, the phenyl‐substituted methylenebisphosphonate 2c could be obtained in only 75% selectivity. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:350–354, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20558     

Synthesis of novel substituted pyridine derivatives from 3,5‐diacetyl‐2,6‐dimethylpyridine

A series of novel (1‐acetyl‐5‐aryl‐4,5‐dihydro)‐1H‐pyrazole substituted pyridine derivatives and poly substituted [2,3′‐bipyridine]‐5‐carbonitrile derivatives were synthesized from 3,5‐diacetyl‐2,6‐dimethylpyridine. The structures of two typical 3,5‐bis[1‐acetyl‐5‐(4‐chlorophenyl)‐4,5‐dihydro‐1H‐pyrazol‐3‐yl]‐2,6‐dimethylpyridines [ 3b(1) and 3b(2) ] were confirmed by X‐ray diffraction analysis. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:123–130, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20522     

Synthesis of novel 1,3‐substituted 1H‐[1,2,4]‐triazole‐3‐thiol derivatives

By means of regioselective S‐alkylation of 1H‐1,2,4‐triazole‐3‐thiol ( 1 ), a series of S‐substituted derivatives 2a‐j were synthesized. In certain conditions, the reaction of 2 with arylsulfochlorides, arylisocyanates, and quaternary ammonium salts of azines corresponding compounds were obtained 1‐arylsulfonyl‐ (3a‐d) , 1‐arylcarbonamido‐ ( 4a,b ), and 1‐azinyl‐1,2,4‐ ( 6a‐p ) triazoles. Structures of compounds were confirmed by ¹H NMR and elemental analyses. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 20:405–410, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20565     

Reaction of N‐thioamido amidines with phosphoramide derivatives: Synthesis of 2‐substituted‐1,3,5,2‐triazaphosphorines

The reaction of N‐thioamido amidines 1 with tris(dimethylamino)phosphine or bis(diethylamino)phenylphosphine in refluxing toluene leads to the 1,3,5,2λ³‐triazaphosphorines 2 and 3 , respectively. The condensation results in the release of two molecules of dialkylamine. The sulfuration of the trivalent phosphorus atoms was achieved by the reaction with elemental sulfur, followed by heating in toluene. The structure of the triazaphosphorines 2 and 3 and their thione derivatives 4 and 5 were readily elucidated by means of ¹H, ¹³C, and ³¹P NMR spectroscopy and mass spectrometry. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:272–277, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20546     

New tetrafunctional monomer 1,3‐di(2‐hydroxy‐3‐methacryloyloxypropoxy)benzene in the synthesis of porous microspheres

Synthesis and properties of the new aromatic tetrafunctional methacrylate monomer 1,3‐di(2‐hydroxy‐3‐methacryloyloxypropoxy)benzene are presented. This monomer was applied for the synthesis of porous microspheres. It was copolymerized with trimethylolpropane trimethacrylate in the presence of pore‐forming diluents, decan‐1‐ol and chlorobenzene. Influence of diluents composition on their porous structures was studied. Thermal resistance and tendency to swell in different organic diluents for a chosen sample were also determined. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3190–3201, 2009     

α‐methylene‐γ‐butyrolactones: versatile skin bioactive natural products

Natural products containing an α‐methylene‐γ‐butyrolactone moiety, mainly of the sesquiterpene type, are widely observed in plants, which upon coming into contact with skin, will induce major skin toxicological side effects or phytodermatitis. Indeed two main dermatological pathologies have been associated with a skin exposure to molecules containing an α‐methylene‐γ‐butyrolactone moiety: allergic contact dermatitis (ACD) and chronic actinic dermatitis (CAD). ACD is an immunologically based disease resulting from modifications of epidermal proteins by sensitizers or haptens. Indeed, α‐methylene‐γ‐butyrolactones are highly electrophilic structures that can act as Michael acceptors towards nucleophilic residues of proteins. Cysteine and lysine are the most modified residues leading, in the case of enantiomerically pure lactones, to the formation of diastereomeric adducts. This chemical enantioselectivity induces an enantiospecificity of the allergic reaction, i.e., an individual sensitized to one enantiomer will not develop clinical symptoms when exposed to the other enantiomer and vice versa. Sesquiterpene lactones have been also associated with another pathology that involves UV irradiation and DNA modifications. Interestingly, it was found that α‐methylene‐γ‐butyrolactones, in addition to their electrophilic properties, were highly photoreactive molecules able to react with thymine/thymidine to form [2 + 2] photoadducts in very high yields. In all cases a syn regioselectivity was observed, probably associated with the polarization of the exomethylenic bond. This high photoreactivity of α‐methylene‐γ‐butyrolactones towards thymidine could be an explanation of the progressive evolution of allergic contact dermatitis towards chronic actinic dermatitis. © 2009 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 9: 000–000; 2009: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.200900013     

Water soluble azido polyisocyanopeptides as functional β‐sheet mimics

The design and synthesis of functional biomimetic water soluble polymers with a defined secondary structure has been developed using β‐sheet polyisocyanopeptide scaffolds. Water soluble isocyanopolymers were prepared by random copolymerisation of the azido functionalized isocyanopeptides with nonfunctionalised methyl ester isocyanides derived from alanine. Upon saponification of the latter function a rigid rod water soluble polymer was obtained with an accessible azide for postfunctionalization. The potential of these biomimetic polymers was successfully demonstrated by using the click chemistry reaction of these polymers with an acetylene functionalised rhodamine dye. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4150–4164, 2009     

Synthesis and spectroscopic investigation of π‐conjugated (E)‐enyne polycarbazole with different organo‐metallic catalysts from 3,6‐diethynyl‐9‐(2‐ethylhexyl)carbazole

In the present study, a new (E)‐rich‐enyne π‐conjugated polymer containing a carbazole was designed and synthesized. Two different synthesis methods of poly[N‐(2‐ethylhexyl)‐3,6‐carbazolyleneethynylene‐(E)‐vinylene] (PCZEV) have been prepared from 3,6‐diethynyl‐9(2‐ethylhexyl)carbazole by using the palladium‐carbene‐catalyzed reaction and/or by using the organolanthanide‐catalyzed reaction leading to well‐defined polymer, and their general properties were studied. Compared to poly[N‐(2‐ethylhexyl)‐3,6‐carbazolyleneethynylene] (PCE), the UV‐vis absorption and photoluminescence of the PCZEV was red‐shifted, which indicates the extension of conjugation length. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2434–2442, 2009