Polymerization of conjugated 5‐[(5‐ethynyl‐1‐naphthyl)ethynyl]‐N,N‐dimethylnaphthalen‐1‐amine with rhodium and palladium complexes

The monomer 5‐[(5‐ethynyl‐1‐naphthyl)ethynyl]‐N,N‐dimethylnaphthalen‐1‐amine was satisfactory obtained through the heterocoupling reaction of 5‐ethynyl‐N,N‐dimethylnaphthalen‐1‐amine and 4‐(5‐iodo‐1‐naphthyl)‐2‐methyl‐3‐butyn‐2‐ol catalyzed by a palladium–copper system, followed by acetone elimination. Poly{5‐[(5‐ethynyl‐1‐naphthyl)ethynyl]‐N,N‐dimethylnaphthalen‐1‐amine} was obtained through the reaction of the acetylene monomer with homogeneous rhodium and palladium catalyst complexes. The structure of the polymers always showed a trans–cisoidal chain configuration on the basis of IR and NMR spectra. Moreover, only for the rhodium catalyst complex in methanol was a dimeric product isolated in a very low yield, having a conjugated terminal ene–yne structure, which permitted the consideration of a metallated chain‐transfer intermediate in the polymer propagation. The mass determination of the polymers, by osmometry and gel permeation chromatography techniques, showed low average molecular weights. The kinetics of the catalyzed polymerization were analyzed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2038–2047, 2007     

3‐Aryl‐5‐furylpyrazolines and their biological activities

Aryl‐furyl substituted pyrazolines 2a–c and 4a–c were prepared by the reaction of α,β‐unsaturated carbonyl compounds with hydrazine or phenyl hydrazine. N‐chloroacetyl derivatives 3a–c were obtained by the N‐acetylation of 2a–c . The antibacterial activities of synthesized pyrazolines were examined by employing the disk‐diffusion technique. All synthesized compounds showed antibacterial effects in 1200 μg concentration. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:345–347, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10159     

Synthesis and polymerization of 5‐(N,N‐dimethylamino)naphthylacetylene with homogeneous rhodium and palladium complexes

The monomer 5‐ethynyl‐N,N‐dimethylnaphthalen‐1‐amine ( 2 ) was satisfactorily obtained by a heterocoupling reaction between 5‐iodo‐(N,N‐dimethyl)naphthalen‐1‐amine and 2‐methyl‐3‐butyn‐2‐ol catalyzed by a palladium–copper system and followed by acetone elimination. Poly(5‐ethynyl‐N,N‐dimethylnaphthalen‐1‐amine) was isolated by the reaction of 2 in the presence of homogeneous rhodium and palladium complexes. On the basis of the spectroscopic data, the polymer always showed a cis–transoidal, stereoregular structure. Moreover, only with the rhodium catalyst in methanol was a dimeric product isolated in a very low yield, having a conjugated terminal ene–yne structure, which permitted the consideration of a metallated chain‐transfer intermediate in the polymer propagation. The kinetics of the catalyzed reaction were analyzed. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 437–446, 2007     

Facile synthesis of 2‐alkylthio‐5‐phenylmethylene‐4H‐imidazol‐4‐ones

2‐Alkylthio‐5‐phenylmethylidene‐4H‐imidazol‐4‐ones 4 were synthesized by S‐alkylation of 2‐thioxo‐3‐alkyl(aryl)‐4‐imidazolidinones 3 , which were obtained via cyclization of isothiocyanates 2 with aliphatic(aromatic) primary amines. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:348–351, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10160     

Microwave‐assisted synthesis and diels–alder reactions of 1,3‐azaphospholo[5,1‐a]isoquinolines

The application of microwave technique has been extended successfully for the first time to the synthesis of a representative class of azaphospholes, viz. 1,3‐bis(alkoxycarbonyl)‐1,3‐azaphospholo[5,1‐a]isoquinolines ( 2 ), which occurs rapidly giving higher yields. Stereoselectivity is observed in the reaction with 2,3‐dimethyl‐1,3‐butadiene, and isoprene reacts regioselectively as well. 1‐Methyl‐3‐ethoxycarbonyl‐1,3‐azaphospholo[1,5‐a]pyridine ( 4 ) remains inert toward [2+4] cycloaddition. The nonoccurrence of the Diels–Alder reaction in the latter case has been supported by semiempirical PM3 calculations. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:560–563, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10193     

Synthesis and properties of new soluble triphenylamine‐based aromatic poly(amine amide)s derived from N,N′‐bis(4‐carboxyphenyl)‐N,N′‐diphenyl‐1,4‐phenylenediamine

A new triphenylamine‐containing aromatic dicarboxylic acid, N,N′‐bis(4‐carboxyphenyl)‐N,N′‐diphenyl‐1,4‐phenylenediamine, was synthesized by the condensation of N,N′‐diphenyl‐1,4‐phenylenediamine with 4‐fluorobenzonitrile, followed by the alkaline hydrolysis of the intermediate dinitrile compound. A series of novel triphenylamine‐based aromatic poly(amine amide)s with inherent viscosities of 0.50–1.02 dL/g were prepared from the diacid and various aromatic diamines by direct phosphorylation polycondensation. All the poly(amine amide)s were amorphous in nature, as evidenced by X‐ray diffractograms. Most of the poly(amine amide)s were quite soluble in a variety of organic solvents and could be solution‐cast into transparent, tough, and flexible films with good mechanical properties. They had useful levels of thermal stability associated with glass‐transition temperatures up to 280 °C, 10% weight‐loss temperatures in excess of 575 °C, and char yields at 800 °C in nitrogen higher than 60%. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 94–105, 2003     

Synthesis and antimicrobial activity of N‐substituted N′‐[6‐methyl‐2‐oxido‐1,3,2‐dioxaphosphinino(5,4‐b)pyridine‐2‐yl]ureas

N‐Substituted N′‐[6‐methyl‐2‐oxido‐1,3,2‐dioxaphosphinino(5,4,‐b)pyridine‐2‐yl]ureas have been accomplished by condensation of equimolar quantities of chlorides of various carbamidophosphoric acids ( 3 ) with 3‐hydroxyl‐6‐methyl‐2‐pyridinemethanol (lutidine diol) ( 4 ) in the presence of triethylamine in dry toluene–tetrahydrofuran (1:1) mixture at 45–50°C. Their structures were established by elemental analyses, IR, ¹H NMR, ¹³C NMR, and ³¹P NMR spectral data. Their antifungal and antibacterial activity is also evaluated. Most of these compounds exhibited moderate antimicrobial activity in the assays. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:509–512, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10181     

2,2,2‐triaryl‐4‐oxo‐1,3,2‐benzoxazastibinines

The hitherto unreported 4‐oxo‐1,3,2‐benzoxazastibinines 2 have been synthesized by the cyclization of disodium salt of salicylanilide ( 1 ) with Ar₃SbBr₂ (Ar = Ph, p‐tolyl, or mesityl). These compounds have been characterized by elemental analyses, molecular weight determination, and by IR, far IR, ¹H, and ¹³C NMR spectral studies. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:622–624, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10202     

Synthesis of 3′‐1,2,4‐triazolo‐ and 3′‐1,3,4‐thiadiazoliminothymidines

New 5′‐acetyl‐3′‐1,3,4‐thiadiazoliminothymidines 11, 14 were prepared, via spontaneous rearrangments, by cycloaddition of 5′‐acetyl‐3′‐deoxy‐3′‐isothiocyanatothymidine 9 with 1‐aza‐2‐azoniaallene hexachloantimonates. Similary, 3′‐cyano analogue 19 was reacted with the same cumulenes to furnish 3′‐1,2,4‐triazolo‐thymidines 22, 24 , and 26 . Deblocking of the acylated products afforded the free nucleosides. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:298–303, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10146     

Synthesis of Bis(imidazole‐2‐thion‐4‐yl)phosphanes

Novel bis(imidazole‐2‐thion‐4‐yl)‐ phosphanes ( 2a–d ) were synthesized via lithiation of the precursor imidazole‐2‐thiones followed by the phosphanylation reaction. Oxidation of bis(imidazole‐2‐thion‐4‐yl)phosphane 2b–d with elemental sulfur and selenium led selectively and in good yields to the P‐thio ( 3b–d ) and P‐seleno ( 4c ) derivatives of bis(imidazole‐2‐thion‐4‐yl)phosphanes, respectively. The treatment of 2a,c with phosphorus trichloride gives the corresponding P‐chloro derivatives 5a,c . These compounds were unambiguously characterized by elemental analyses, spectroscopic and spectrometric methods, in addition by single‐crystal X‐ray structure analysis in the case of 2d . © 2012 Wiley Periodicals, Inc. Heteroatom Chem 00:1–7, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21043     

3‐Methylthio‐pyrano[4,3‐c]pyrazol‐4(2H)‐ones from 3‐(bis‐methylthio)methylene‐2H‐pyran‐2,4‐diones and hydrazines

A useful synthesis of 3‐methylthio‐6‐methyl‐pyrano[4,3‐c]pyrazol‐4(2H)‐ones via 3‐(bis‐methylthio)methylene‐5,6‐dihydro‐6‐alkyl(aryl)‐2H‐pyran‐2,4‐dione with hydrazine as well as methyl and phenyl hydrazines is described and the mechanism of the formation is discussed. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:342–344, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10158     

Cationic and mesoionic 1,3‐thiazolo‐[3,2‐c]quinazoline derivatives

4‐Allylthio‐2‐arylquinazolines 4a–c undergo cyclization by action of bromine to furnish 5‐aryl‐3‐bromomethyl‐2,3‐dihydrothiazolo[3,2‐c]quinazolin‐4‐ium bromides 5a–c . Compounds 5a–c undergo ring opening by action of water under acid catalysis to afford the corresponding dibromide derivatives 6a–c . Bromination of 3‐allyl‐2‐aryl‐4(3H)quinazolinethiones 7a–c leads to 5‐aryl‐2‐bromomethyl‐2,3‐dihydrothiazolo[3,2‐c]quinazolin‐4‐ium bromides 8a–c . However, anhydro‐3‐hydroxy‐5‐aryl‐1,3‐thiazolo[3,2‐c]quinazolin‐4‐ium hydroxide 10a–c were prepared by the cyclodehydration of the corresponding thioglycolic acids 9a–c with Ac₂O. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:576–580, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10148     

2,6‐Diaryl‐4,4‐disubstituted 1,4‐dihydropyridines: Source for spiro heterocycles

Novel spiro heterocycles ( 5–12 ) were obtained by the cyclocondensation of 2,6‐diaryl‐4,4‐dimethoxycarbonyl‐/4‐cyano‐4‐ethoxycarbonyl‐1,4‐dihydropyridines( 3/4 ) with hydrazine hydrate, hydroxylamine hydrochloride, urea, and thiourea. All the compounds were characterized by IR, ¹H NMR, and ¹³C NMR spectral data.© 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:513–517, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10183     

Synthesis of ribosylated 1,2,3‐triazole derivatives

Ribosylated 1,2,3‐triazole 4 and 5 were synthesized in moderate yields by the reaction of aroyl‐substituted heterocyclic ketene aminals 1 or 2 with 2,3,5‐tri‐O‐benzoyl‐β‐D ‐ribofuranosyl azide ( 3 ). Their structures were determined by elemental analyses and spectroscopic methods. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:487–490, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10167     

Reaction of ω‐carbonyl substituted 1,3,3‐trimethyl‐2‐methyleneindolines with phosphorus(III) halides

The phosphorylation of N‐benzoyl‐2‐(1,3,3‐trimethyl‐2‐methyleneindoline)acetamide ( 2 ) and ω‐(3‐dimethylamino)benzoyl‐1,3,3‐trimethyl‐2‐methyleneindoline ( 6 ) with phosphorus(III) halides resulted in the formation of 2,3‐dihydro‐4H‐1,5,2‐oxazaphosphinin‐4‐one and 1,2‐dihydro‐3H‐phosphindol‐3‐one systems, respectively. The properties of the obtained compounds were studied. Further cyclization of 1,2‐dihydro‐3H‐phosphindol‐3‐one into dihydrophosphindolo[3,2‐c]pyrazole was carried out. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:23–28, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10060     

Construction of a combinatorial library of 2‐(4‐oxo‐4H‐1‐benzopyran‐3‐yl)‐4‐thiazolidinones by microwave‐assisted one‐pot parallel syntheses

A one‐pot liquid‐phase combinatorial synthesis of 2‐(4‐oxo‐4H‐1‐benzopyran‐3‐yl)‐4‐thiazolidinones bearing diverse substituents at the 3‐position under microwave irradiation was successfully performed using 3‐formyl chromone, primary amine, and mercaptoacetic acid as reactants. Compared to an identical library generated by conventional parallel synthesis, the microwave‐assisted parallel synthesis approach dramatically decreased the reaction time from an average of 9 h to 5 min, and substantially increased the product yields. The coupling of microwave technology with liquid‐phase combinatorial synthesis constitutes a novel and particularly attractive avenue for the rapid generation of structurally diverse libraries. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:381–389, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20309     

Fragmentation‐related phosphinylations using 2‐aryl‐2‐phosphabicyclo[2.2.2]oct‐ 5‐ene‐ and ‐octa‐5,7‐diene 2‐oxides

A series of new P‐methylphenyl P‐heterocycles are introduced. The para and ortho substituted 2,5‐dihydro‐1H‐phosphole oxides ( 1a and 1b ) were converted to the double‐bond isomers ( A and B ) of 1,2‐dihydrophosphinine oxides ( 3a and 3b ) via the corresponding phosphabicyclo[3.1.0]hexane oxides ( 2a or 2b ). Isomeric mixture ( A and B ) of the dihydrophosphinine oxides ( 3a and 3b ) gave, in turn, the isomers ( A and B ) of phosphabicyclo[2.2.2]oct‐5‐enes ( 4a and 4b ) or a phosphabicyclo[2.2.2]octa‐5,7‐diene ( 5 ) in Diels‐Alder reaction with dienophiles. The bridged P‐heterocycles ( 4 and 5 ) were useful in the photo‐ or thermoinduced fragmentation‐related phosphinylation of hydroxy compounds and amines. The new precursors ( 4a and 4b ) were applied in mechanistic investigations. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:443–451, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10176     

Convenient synthesis of optically active α‐hydroxyphosphinic acids

The reaction of O‐menthyl phenylphosphonite 1 with aromatic aldehydes in the presence of Me₃SiCl provided the O‐menthyl α‐hydroxyphosphinates 2 . Acidic hydrolysis of 2 gave the corresponding α‐hydroxyphosphinic acids 3 . The (+)‐enantiomer of 3a and 3b , adduct of benzaldehyde and 4‐methylbenzaldehyde respectively, were obtained via multiple recrystallization. The absolute configuration of (+)‐ 3a was determined as S by X‐ray crystallography. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:312–315, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10150     

Cycloaddition of N‐(2,2,2‐trichloroethylidene)‐substituted carboxamides and carbamates to 1,2,4‐thiadiazol‐5(2H)‐imines

1,2,4‐Thiadiazol‐5(2H)‐imines 4 react with N‐(2,2,2‐trichloroethylidene)‐substituted amides 5 to form [3 + 2]‐cycloaddition products 6 featured by an extra coordination of the ring sulfur atom to the terminal nitrogen atom of the side 1,3‐diazapropenylidene group, as established by X‐ray diffraction investigation. This coordination evidently plays an important role in the alkylation of compounds 6 into 8 at the oxygen atom under mild conditions. The S N bond “switch‐over” restoring the original 1,2,4‐thiadiazole ring occurs therewith. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:474–480, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10182     

Synthesis of optically active N‐protected α‐aminoketones and α‐amino alcohols

A series of optically active N‐protected α‐aminoketones were synthesized via the Grignard reaction of the Weinreb amides of the N‐tert‐butoxycarbonyl amino acids. Reduction of the α‐aminoketones by sodium borohydride resulted in the corresponding 1,2‐amino alcohols. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:603–606, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10195