- A convenient synthesis of dialkyl [[2-(bromomethyl)aziridin-1-yl]methyl]phosphonates, new heterocyclic β-azaphosphonates
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Dialkyl [[2-(bromomethyl)aziridin-1-yl]methyl] phosphonates were prepared in good yield by a convenient procedure involving the reaction of 1,3,5-triallylhexahydro[1,3,5]triazine with dialkyl phosphites, subsequent bromination and final ring closure upon treatment with sodium borohydride in methanol.
- Stevens, Christian,Verbeke, Aart,De Kimpe, Norbert
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- Selective trimerisation and polymerisation of ethylene: Halogenated chromium triazacyclohexane complexes as probes for an internal 'halogen effect' Dedicated to Prof. John Bercaw on the occasion of his 70th birthday
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A range of triazacyclohexane (R3TAC) complexes of CrCl3 with unsaturated N-substituents R have been prepared. The complexes with R = allyl (3f) and CH2CH(CH2CH = CH2)2 (3h) have been characterised by X-ray crystallography. Addition of HX or X2 (X = Cl or Br) across the double bonds of the complexed ligand gives access to β- and γ-branched N-substituents containing three to twelve organic halogen atoms. The complexes with R = CH2CHBrCH2Br (3k), CH2CH2CX(nC5H11)2 (X = Cl (3n) and Br (3o)) have been characterised by X-ray crystallography. N-substituent chlorinated complexes can also be prepared via alkyl chloride containing amines as demonstrated for a crystal structure of a complex with R = (CH2)3Cl (3e). Complexes with β-branched N-substituents give high selectivity for ethylene trimerisation to 1-hexene while complexes with γ-branched N-substituents are good ethylene polymerisation catalysts. The halogenated polymerisation catalysts give higher activities than their hydrogenated analogues, especially chlorine containing species. Chlorinated trimerisation catalysts demonstrated significantly improved 1-hexene selectivities, though activity was similar to hydrogenated alternatives. This lends support to the concept of a positive 'halogen effect' on the catalysis.
- K?hn, Randolf D.,Coxon, Alexander G.N.,Hawkins, Christopher R.,Smith, David,Mihan, Shahram,Schuhen, Katrin,Schiendorfer, Michael,Kociok-K?hn, Gabriele
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- Facile Access to 3-Unsubstituted Tetrahydroisoquinolonic Acids via the Castagnoli-Cushman Reaction
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Hitherto undescribed 3-unsubstituted tetrahydroisoquinolonic acids (isolated as their respective methyl esters) were accessed for the first time by the uncatalyzed, thermally promoted Castagnoli-Cushman reaction (CCR) of homophthalic anhydride (HPA) and a series of 1,3,5-triazinanes. The moderate yields observed in some cases are most likely associated with a persistent impurity also formed in these reactions. The new scaffold is expected to find novel medicinal utility (compared to the traditional CCR adducts) because it lacks a substituent at the 3-position.
- Guranova, Natalia,Dar'In, Dmitry,Krasavin, Mikhail
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p. 2001 - 2008
(2018/03/06)
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- Synthesis of 2,3-dihydroimidazo[2,1-b]thiazole derivatives via cyclization of N-allylimidazoline-2-thiones
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A novel method for the preparation of 2,3-dihydroimidazo[2,1-b]thiazole 9 by iodination and subsequent cyclization of the easily available N-allylimidazoline-2-thiones 5, is described. Selected transformations of the iodomethyl derivatives 9, leading to methylidene compounds 10 or the sulfide 11 (Nu = RS), via elimination with a base or via substitution with an enolizable imidazoline-2-thione (the term "1,3-dihydroimidazole-2-thione" will be used alternatively), respectively, are presented.
- Jasinski, Marcin,Mloston, Grzegorz,Heimgartner, Heinz
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experimental part
p. 1287 - 1293
(2011/01/05)
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- CYCLIC COMPOUND, PROCESS FOR PRODUCING THE SAME, AND PEST CONTROL AGENT
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A compound represented by the formula: wherein, A represents a group represented by the formula: CY1Y2OCY3Y4, CY1Y2SOnCY3Y4, CY1Y2NRCY3Y4, CY1=NCY3Y4 or CY1Y2N=CY3 (wherein n is 0, 1, or 2, and Y1, Y2, Y3, and Y4 each independently represents hydrogen, alkyl, or haloalkyl); R represents hydrogen, halogen, an optionally substituted hydrocarbon group, etc.; Q1 represents substituted phenyl or a substituted aromatic heterocyclic group; and Q2 represents substituted phenyl, alkyl, or haloalkyl, or a salt. thereof; a process for producing the. compound or a salt thereof; and an insecticide containing. the same. Besides being applicable by spraying, the insecticide can be used for soil treatment and seed treatment.
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- Preparation of N,O-Aminals as Synthetic Equivalents of H2C=NAr and (H2C=NHAr)+ ions: Neutral- and Acid-promoted Transformations
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A general method for the synthesis of N, O-aminals derived from primary aromatic amines is described.The reactivity of these compounds under neutral and acidic conditions has been studied and the title compounds can be envisaged as general purpose H2C=NAr or (H2C=NAr)+ equivalents.N,O-Aminals have been converted into perhydrotriazines by moderate heating and into bis(4-aminoaryl)methane derivatives or N-benzylarylamines, respectively, when heated in acidid media with pH control.Reduction od N,O-acetals with sodium cyanoborohydride has revealed that the C-O bond is broken exclusively in acidic media.
- Barluenga, Jose,Bayon, Ana M.,Campos, Pedro,Asensio, Gregorio,Gonzalez-Nunez, Elena,Molina, Yolanda
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p. 1631 - 1636
(2007/10/02)
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- SYNTHESE D'IMINES LINEAIRES NON-STABILISEES PAR REACTIONS GAZ-SOLIDE SOUS VIDE(1).
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Unstabilized imines are synthetized in gram-scale by vacuum dehydrochlorination of N-chloroalkylamines and by vacuum dehydrocyanation of α-aminonitriles on solid base.All the new compounds are characterized at low temperature by 1H, 13C NMR and IR spectroscopy.
- Guillemin, Jean-Claude,Denis, Jean-Marc
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p. 4431 - 4446
(2007/10/02)
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- Flash Vacuum Thermolysis of α-Aminonitriles and Subsequent HCN Removal on Solid Base, a 'One Line' Multistep Sequence to Reactive N-Methyleneamines
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Reactive methyleneamines bearing alkyl or functional groups are isolated at low temperature in the condensate state by flash vacuum thermolysis of α-aminonitriles and subsequent vapour phase HCN removal on solid base.
- Guillemin, J. C.,Denis, J. M.
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p. 951 - 952
(2007/10/02)
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- Method for preparation of N-phosphonomethylglycine
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A process for preparing N-phosphonomethylglycine which comprises: (1) reacting a primary amine with formaldehyde to produce N,N', N"-tris-substituted-hexahydro-s-triazine; (2) reacting the triazine with an haloacetyl halide, preferably chloroacetyl chloride, to form the N-(substituted)-N-halomethyl acetamide of the haloacetyl halide; (3) reacting the amide with O,O-di-(substituted)-aminomethylphosphonate to form O,O-di-(substituted)-1-phosphonomethyl-3-(substituted)-1,3-imidazol-4-one; and (4) hydrolyzing the 1,3-imadazol-4-one to yield N-phosphonomethylglycine.
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- Enamine Chemistry. Part 27. The Effect of Additional α- and β-Heteroatoms on the p?-Conjugation and Reactivity of Enamines. Sub- or Super-Enamines?
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Enamines derived from isoxazolidine and 1,3-dioxa-5-azacyclohexane have been prepared.The effect of the addition a α- or β-heteroatoms is to decrease the p?-conjugation between the nitrogen lone pair of electrons and the ?-electrons of the double bond, as reflected in the spectral properties of the enamines and their reactivity with electrophiles.The reasons for this are discussed.
- Ahmed, Md. Giasuddin,Ahmed, S. Asghari,Hickmott, Peter W.
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p. 2383 - 2386
(2007/10/02)
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