Facile synthesis of N,N‐dialkylselenoamides from amides

N,N‐Dialkylamides were chlorinated with oxalyl chloride and then allowed to react with LiAlHSeH to afford the corresponding N,N‐dialkyselenoamides in moderate to good yields. The N,N‐dialkylamides bearing bulky substituent groups were not converted into the corresponding selenoamides because of their steric hindrance. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:195–198, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10016     

C‐phosphorylation of N‐arylpyrroles

Phosphorylation of N‐arylpyrroles with phosphorus tribromide proceeds regioselectively at the position 2 of the heterocyclic system. A 2‐to‐3 migration of the dibromophosphino group has been discovered, with its ease depending on the electronic nature of a substituent on the phenyl ring, solvent polarity, and the presence of pyridine hydrobromide in the reaction mixture. Further phosphorylation of 2‐ and 3‐monophosphorylated N‐arylpyrroles regioselectively involves the respective positions 4 and 5 of the heterocycle and is governed by the electron‐acceptor effect of the phosphorus‐containing substituent. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:223–228, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10012     

Regioselective N‐alkylation for the synthesis of novel aminotriazolophanes

Regioselective synthesis of macrocycles, incorporating 3‐oxo‐4‐amino‐1,2,4‐triazole derivatives, has been achieved by reactions involving N‐alkylation, utilizing appropriate 1, ω ‐dihaloalkanes in the presence of metal hydroxide. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:329–336, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20211     

Synthesis and biological activity of novel N‐benzoyl‐N‐tert‐butyl‐N′‐(β‐triphenylgermyl)propionylhydrazines

A series of new N‐benzoyl‐N‐tert‐butyl‐N′‐(β‐triphenylgermyl)propionylhydrazines were synthesized by the condensation reaction of β‐triphenylgermyl propanoic acid with N‐benzoyl‐N‐tert‐butylhydrazines in good yields by using N,N′‐dicyclohexylcorbodiimide as dehydrating agent. These title compounds were evaluated for molting hormone mimicking activity. The results of bioassay showed that the compounds exhibit moderate larvicidal activity, and toxicity assays indicated that the title compounds can induce a premature, abnormal and lethal larval molt. We found that the title compounds possess potential anticancer activities in vitro. Copyright © 2002 John Wiley & Sons, Ltd.     

Synthesis of novel N‐alkyl/aryl‐N′‐(4‐arylthiazol‐2‐yl)‐N″‐xylosyl guanidines

The reaction of 2,3,4‐tri‐O‐acetyl‐β‐D‐xylopyranosyl isothiocyanate ( 1 ) and 2‐amino‐4‐arylthiazoles ( 2 ) gave xylosylthioureas 3 . These thiourea derivatives reacted with alkyl/aryl amine in the presence of HgCl₂ to give a new series of N‐alkyl/aryl‐N″‐(4‐arylthiazol‐2‐yl)‐N″‐xylosyl guanidines 4 . Some of the synthesized guanidines were screened for their biological activity. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:688–694, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20379     

Organometallic chemistry of silver and copper N‐heterocyclic carbene complexes

The only stable organometallic carbene complexes of silver and copper are those of N‐heterocyclic carbenes, since formally these robust divalent carbon ligands bind only by a σ donor interaction to the metal. A survey of the range of complexes that have now been reported is presented. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:534–539, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10098     

Synthesis and insecticidal evaluation of N‐tert‐butyl‐N′‐thio[O‐(1‐methylthioethylimino)‐N″‐methylcarbamate]‐N,N′‐diacylhydrazines

A series of novel N‐tert‐butyl‐N′‐thio[O‐(1‐methylthioethylimino)‐N″‐methylcarbamate]‐N,N′‐diacylhydrazines were synthesized by the reaction of chlorosulfenyl[O‐(1‐methylthioethylimino)‐N‐methylcarbamate] with N‐tert‐butyl‐N,N′‐diacylhydrazine in the presence of sodium hydride. The reaction of sulfur dichloride with O‐(1‐methylthioethylimino)‐N‐methylcarbamate (Methomyl) in the presence of pyridine to yield chlorosulfenyl[O‐(1‐methylthioethylimino)‐N‐methylcarbamate] was reported for the first time. X‐ray single crystal diffraction of N‐tert‐butyl‐N′‐thio[O‐(1‐methylthioethylimino)‐N″‐methylcarbamate]‐N,N′‐dibenzoylhydrazine demonstrated that the parent compounds N‐tert‐butyl‐N,N′‐dibenzoylhydrazine and O‐(1‐methylthioethylimino)‐N‐methylcarbamate were combined by N S N band to give the product. Their larvicidal activities against Oriental armyworm and Aphis laburni were evaluated. All of them exhibited excellent larvicidal activities against Oriental armyworm, with some of them showing higher larvicidal activities than the parent diacylhydrazines. Toxicity assays indicated that the products show knockdown activity for O‐(1‐methylthioethylimino)‐N‐methylcarbamate at higher concentration and insect growth regulators' activities of diacylhydrazines at lower concentrations. At the same time, the products possess insecticidal activities against the aphids. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:631–636, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20360     

A Stepwise one‐pot synthesis of aryl N‐phosphonamidothionate derivatives of nucleosides

Novel aryl N‐phosphonamidothionate derivatives of nucleosides as membrane‐soluble prodrugs of bioactive free nucleotides have been prepared by phosphochloridothioate chemistry. Unprotected nucleosides, for example uridine and adenosine, were used; phosphorylation took place selectively at the 5′‐position. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:62–66, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10080     

A facile synthesis of 2‐amino‐1,3‐selenazole by reaction of N,N‐unsubstituted selenourea with ketone

2‐Dialkylamino‐1,3‐selenazoles were yielded by the reaction of N,N‐unsubstituted selenoureas with ketones in the presence of ferric chloride. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:88–92, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20180     

A convenient synthesis of N‐t‐butyl‐N′‐aminocarbonyl‐N‐(substituted)benzoyl‐hydrazine containing α‐aminoalkylphosphonate groups in a one‐pot procedure

A variety of novel N‐t‐butyl‐N′‐aminocarbonyl‐N‐(substituted)benzoylhydrazines containing α‐aminoalkylphosphonate groups were synthesized. Treatment of α‐aminoalkylphosphonates with triphosgene yielded α‐isocyanatoalkylphosphonates, and subsequent addition with N‐t‐butyl‐N‐substituted benzoylhydrazines provided the title compounds in a one‐pot procedure with good yields. The triphosgene‐mediated reaction for the synthesis of α‐isocyanatoalkylphosphonates enjoys a number of advantages: the reaction is carried out under mild condition in good yield, triphosgene is relatively safe to handle because of its low vapor pressure and high stability, and the experimental procedure is simple. This method can be applicable to the synthesis of other α‐isocyanatoalkyl‐phosphonates and urylenediphosphonates. The structures of all of the products and by‐products were confirmed by ¹H NMR, ³¹P NMR, IR and mass spectroscopy, and elemental analysis. We also found that some of the compounds possess potential antitobacco mosaic virus (TMV) activities and anticancer activities. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:68–72, 2001     

Simple and efficient synthesis of new chiral N,N′‐sulfonyl bis‐oxazolidin‐2‐ones

A series of new chiral N,N′‐sulfonyl bis‐oxazolidin‐2‐ones were synthesized starting from 2‐aminoalcohols, sulfuryl chloride, and diethyl carbonate. This method utilizes natural amino acids as a source of chirality for the preparation of oxazolidinones. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:61–65, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20183     

Influence of colloid suspensions of humic acids on the alkaline hydrolysis of N‐methyl‐N‐nitroso‐p‐toluene sulfonamide

The influence of humic substances (HSs) upon the alkaline hydrolysis of N‐methyl‐N‐nitroso‐p‐toluene sulfonamide has been studied. Important inhibition of hydrolysis reaction has been reported. This inhibition has been explained in terms of association of reactants to the humic substances. Kinetic results have been modeled using the micellar pseudophase model. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 316–322, 2010     

Arylation reaction of N‐dichlorophosphoryl‐P‐trichlorophosphazene

The reactions of N‐dichlorophosphoryl‐P‐trichlorophosphazene (Cl₃PN POCl₂) with phenylmagnesium chloride, o‐tolylmagnesium chloride, p‐tolylmagnesium chloride, p‐chlorophenylmagnesium chloride, 2‐mesitylmagnesium bromide, and 2‐thienyl lithium were studied. The resulting pentaaryl phosphazenes R₃PN P(O)R₂ were separated by using column chromatography, their structures were defined by IR, elemental analysis, ¹H, ¹³C, ³¹P NMR, and mass spectroscopy. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:138–143, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10114     

The synthesis of novel acetolactate synthase inhibitors,N‐(asymmetrically disubstituted phosphoryl)‐N′‐(4,6‐dimethoxypyrimidin‐2‐yl) ureas

In view of the isosterism of the sulfonyl group(‐SO₂‐) and the phosphoryl group, two new types of compounds N‐(N‐aryl‐O‐alkyl phosphoryl)‐N′‐(4,6‐dimethoxypyrimidin‐2‐yl) ureas (2) and N‐(N‐aryl‐N‐alkylphosphoryl)‐N′‐(4,6‐dimethoxypyrimidin‐2‐yl) ureas (3) were designed and synthesized by treating N‐(arylaminochlorophosphoryl)‐N′‐(4,6‐dimethoxypy‐rimidinyl‐2‐) ureas (4) with alcohols or amines. Compounds 4 were obtained by treating dichloro‐phosphoryl isocyanate with 4,6‐dimethoxy‐2‐amino‐pyrimidine and then with aromatic amines. The enzyme tests in vitro indicated that compounds 2 and 3 were two novel classes of acetolactate synthase (ALS) inhibitors and also showed that phosphoryl groups[‐P(O)(OR)‐, R=alkyl] and [‐P(O)(NHR), R=alkyl] were likely to be good bioisosteres of the sulfonyl group (‐SO₂‐) in the sulfonylureas. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10:237–241, 1999     

Gas‐phase pyrolytic reactions of N‐ethyl,N‐isopropyl,and N‐t‐butyl substituted 2‐aminopyrazine and 2‐aminopyrimidine

The rates of gas‐phase elimination of N‐ethyl (1), N‐isopropyl (2), N‐t‐butyl (3) substituted 2‐aminopyrazine and N‐ethyl (4), N‐isopropyl (5), and N‐t‐butyl (6) substituted 2‐aminopyrimidine have been measured. The compounds undergo unimolecular first‐order pyrolytic reactions. The relative rates of the primary:secondary;tertiary alkyl homologues at 600 K are 1:14.4:38.0 for the pyrazines and 1:20.8:162.5 for the pyrimidines, respectively. The reactivities of these compounds have been compared with those of the alkoxy analogues and with each other. Product analyses, together with the kinetic data, were used to outline a feasible pathway for the elimination reaction of the compounds under study. © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 403–407, 2000     

Efficient synthesis and NMR data of N‐ or B‐substituted borazines

The thermolysis of borane‐primary amine complexes RNH₂.BH₃ was reexamined. Excellent yields of N‐substituted borazines were obtained at 200°C, when R is an alkyl group, and at 120°C for R = Ph. B‐alkyl, vinyl, and alkynyl borazines were easily prepared in good to excellent yields by ammonolysis of bis(diisopropylamino)organoboranes at temperatures above 95°C. The ¹H, ¹³C, and ¹⁵N or ¹⁴N NMR data for all borazines prepared are reported for the first time. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:218–225, 2000     

Synthesis of N‐aryl S‐alkylthiocarbamates

Several N‐aryl S‐alkylthiocarbamates were synthesized by reactions of isocyanates with LiAlHSH and then with alkyl halides. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:374–378, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10163     

2‐Benzothiazolyl‐N‐(arenesulfonyl)‐sulfinimidoyl fluorides

2‐Benzothiazolyl‐N‐(arenesulfonyl)‐sulfinimidoyl fluorides were synthesized by the treatment of benzothiazolyl‐2‐sulfur trifluoride with sulfonamides. The reaction of 2‐benzothiazolyl‐N‐ (p‐toluenesulfonyl)‐sulfinimidoyl fluoride with tert‐ butylamine and morpholine gave 2‐benzothiazolyl‐ N‐(arenesulfonyl)‐sulfinimidoyl amides. The reaction of 2‐benzothiazolyl‐N‐(p‐toluenesulfonyl)‐sulfinimi‐ doyl fluoride or 2‐benzothiazolyl‐¹⁵N‐(p‐tosyl)sul‐ finimidoyl fluoride with S‐trimethylsilylbenzenethiol gave di(benzothiazolyl‐2) disulfide, fluorotrimethylsi‐ lane and N,N′‐bis(p‐toluenesulfonyl)‐N,N′‐bis(phenyl‐ thio)‐hydrazine or ¹⁵N,¹⁵N′‐bis(p‐toluenesulfonyl)‐¹⁵N, ¹⁵N′‐bis(phenylthio)‐hydrazine, respectively. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:352–356, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20102     

Novel synthesis of N,N′‐dialkyl cyclic ureas using sulfur‐assisted carbonylation and oxidation

The first example of cyclic urea synthesis from secondary amines by the use of sulfur‐assisted carbonylation and oxidation was established. By combined sulfur‐assisted carbonylation of secondary α,ω‐diamines under an ambient pressure of carbon monoxide at 20°C with oxidation by molecular oxygen (0.1 MPa, 20°C), a facile synthetic method for N,N′‐dialkyl cyclic ureas including 1,3‐dimethyl‐2‐imidazolidinone was developed. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:64–68, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20508     

Phosphorylation of N‐iso‐propyl‐ and N‐tert‐butylpyrroles with phosphorus(III) halides

The investigation concerns the effect of a bulky substituent at the pyrrole nitrogen atom on the orientation and regioselectivity of pyrrole phosphorylation with phosphorus(III) halides. As shown, phosphorylation of N‐iso‐propylpyrrole with phosphorus tribromide or trichloride proceeds nonregioselectively at positions 2 and 3 but it is followed by the 2 → 3 migration of the dihalogenophosphine group which quantitatively yields the 3‐isomer. N‐tert‐butylpyrrole is regioselectively phosphorylated with halogenophosphines at position 3. The tert‐butyl substituent at the nitrogen atom does not preclude the binding of even two or three pyrrolyl residues to the phosphorus atom. The key compounds, 3‐pyrrolyldihalogenophosphines, were isolated in a pure state, characterized and used to obtain a number of stable phosphorus(V) derivatives. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:599–604, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20158