Derivatives of 1,1,2,2-tetraaminoethane: II. Condensation of 4,5-diacetoxy-1,3-diacetylimidazolidine and 2,3-diacetoxy-1,4-diacetylpiperazine with nitrogen-containing nucleophiles

Reactions of 4,5-diacetoxy-1,3-diacetylimidazolidine and 2,3-diacetoxy-1,4-diacetylpiperazine with acetamide and ethyl carbamate gave 1,3-diacetyl-4,5-bis(acetylamino)imidazolidine, 1,4-diacetyl-2,3-bis(acetylamino)piperazine, 1,3-diacetyl-4,5-bis(ethoxycarbonylamino)imidazolidine, and 1,4-diacetyl-2,3-bis(ethoxycarbonylamino)piperazine, respectively. Condensation products of 4,5-diacetoxy-1,3-diacetylimidazolidine and 2,3-diacetoxy-1,4-diacetylpiperazine with urea, furazan-3,4-diamine, and 4-phenylfurazan-3-amine were isolated.     

Derivatives of 1,1,2,2-tetraaminoethane: I. Condensation of 1,2-diacetoxy-1,2-bis(acylamino)ethanes with nitrogen-containing nucleophiles

Reaction of 1,2-diacetoxy-1,2-bis(acylamino)ethanes with acetamide and urethane gave rise to 1,2-bis(acetylamino)-1,2-bis(acylamino)ethanes and 1,2-bis(acylamino)-1,2-bis(ethoxycarbonylamino)ethanes respectively. Condensation products were isolated of reactions between 1,2-diacetoxy-1,2-bis-(acylamino)ethanes with acetonitrile, diaminofurazan, and 4-phenylfurazan-3-ylamine.     

2-(二硝基亚甲基)-4,5-咪唑烷二酮与甲醇的反应研究

以2-甲基咪唑为原料合成2-(二硝基亚甲基)-4,5-咪唑烷二酮(1), 收率为33.9% (16.8%文献值), 首次采用低碳液态醇实现1的开环反应, 产物为FOX-7. 对反应条件进行了优化, 对比了甲醇、甲酸、氨水三种亲核试剂的开环效果, 开环试剂为甲醇时, FOX-7收率为94.6%, 高于文献值(87.4%). 研究了1的络合性能, 合成了1的甲醇加合物2并进行了结构表征. 对开环反应机理和乙二酰脲的形成机理进行了探讨.     

Cobalt(II) halide complexes with imidazolidine-2-selone derivatives

Summary CoL₂X₂ (X = Cl, Br or I) complexes were obtained by reacting cobalt(II) halides withN-methyl-,N-ethyl-,N,N-dimethyl- andN,N-diethyl-imidazolidine-2-selone. The same ligands with cobalt(II) tetrafluoroborate gave CoL₄(BF₄)₂ complexes only with the disubstituted ligands. On the basis of i.r. and electronic spectra all the complexes are considered to be Se-bonded to the metal with a tetrahedral stereochemistry, as supported by magnetic measurements and colours. The ligand field parameters (Dq, B and ) for the [CoL₄]²⁺ ion are evaluated by using the averaged ligand field approximation. The influence of the substituents on these parameters are discussed and compared with those obtained for the analogous complexes with the sulphur parent ligands.This work was partially supported by C.N.R. of Rome, Italy.     

Copper(II) complexes of 2-(pyridine-2-yl)imidazolidine-4-thione derivatives for asymmetric Henry reactions

The preparation of a new series of 2-(pyridine-2-yl)imidazolidine-4-thione derivatives is described. Their corresponding copper(II) complexes were found to be highly enantioselective catalysts for asymmetric Henry reactions (up to 98% ee). Immobilization of these complexes by anchoring onto Merrifield? resin with respect to their use as recyclable catalysts was subsequently performed. The heterogeneous catalysts prepared in this way were tested in the asymmetric Henry reactions and showed high catalytic activity; they can be easily recycled, although their enantioselectivities were only moderate (～50% ee).     

Quinazolinone derivatives. Kinetics of the reaction of 2-chloromethyl-3-hydroxy-4-(3H)quinazolinone with nucleophiles

Reaction of 2-Chloromethyl-3-hydroxy-4(3H)quinazolinone ( 1 ) with aliphatic amines and hydroxide follows two different routes affording substituted methyl quinazolinones and a dimer 2 derived from 1 . The former were formed by S_N² reactions while the latter was formed by an inter-molecular nucleophilic displacement. Second-order and third-order rate constants, respectively, were determined, and the kinetic factors influencing both parallel reactions were analysed.     

2-Imidazolines. III (1). 1-Aryl- and 1-acyl-2-amino-(ormethoxy)-4,5-diamino-4,5-dihydroimidazoles. Synthesis and properties

Diimmonium salt (5) reacts with guanidines (6) and o-methylisoureas (7) affording 2-amino-4,5-dimorpholinoimidazolines (9) . 1-Aryl-2-amino-4,5-dimorpholinoimidazolines lose the amino functionality under mild acidic conditions with formation of 2-amino-5-morpholinoimidazole derivatives (10) whereas 1-acyl derivatives undergo under the same conditions a ring expansion process leading to pyrimidine derivatives (13) .     

Ethynyl carbonium ions. 2. Reactions of 4-ethynylpyrylium perchlorates with alcohols and nitrogen-containing nucleophiles

Derivatives of -alkoxy- and -(phenylamino)styrylpyrylium salts, the hydrolysis of which leads to phenacylpyrylium salts and 4-benzoylmethylenepyrans, are formed in the reaction of 4-phenylethynylpyrylium salts with alcohols and aromatic amines. Ethynyl-substituted pyridines and pyridinium salts were synthesized by the action of ammonium acetate and methylamine, benzylamine, and butylamine. A -methylaminostyryl-1-methyl-substituted pyridinium salt is formed with excess methylamine.See [1] for Communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 299–306, March, 1990.     

Condensation of 2-(acetamido)cyclohexanone with malononitrile

Depending on the conditions, condensation of 2-(acetamido)-cyclohexanone with malononitrile gives 1-acetyl-2-amino-3-cyano-4,5,6,7-tetrahydroindole or 2-amino-3-cyano-4,5,6,7-tetrahydroindole, from which substituted tetrahydropyrimido[1,2-a]indole and tetrahydropyrimido [4,5-b]indole were synthesized.     

Synthesis of 2-(1-aminocyclopropyl)pyrrolidine-3,4-diol derivatives applying titanium-mediated reaction conditions

The titanium-mediated cyclopropanation reaction using Ti(OⁱPr)₃Me/EtMgBr/BF₃·OEt₂ has been applied to various 2-cyanopyrrolidines for the synthesis of functionalized 2-(1-aminocyclopropyl)pyrrolidine-3,4-diol derivatives (dideoxyiminoalditols). Under the same experimental conditions the trans-5-azidomethyl-2-cyanopyrrolidine derivative was not cyclopropanated but reduced into the corresponding 5-amino-2-cyano derivative. After polyol deprotection 2-(1-aminocyclopropyl)pyrrolidine-3,4-diols were obtained and their inhibitory activity towards 13 glycosidases has been evaluated. (2S,3S,4R,5S)-2-(1-Aminocyclopropyl)-5-methylpyrrolidine-3,4-diol (38), which has the same absolute configuration as l-fucose, is a moderate (IC₅₀=44 μM), but selective, inhibitor of α-l-fucosidase from human placenta.     

Reactions of 1,5-diketones. 42. Synthesis of heterocycles by the reaction of 4,4-dimethyl-1-phenyl-1-(2′-oxocycloalkyl)-3-pentanones with nitrogen-containing nucleophiles

The reaction of 1,5-diketones containing a pivaloyl fragment with several nitrogen-containing nucleophiles was studied. Derivatives of 2-tert-butyl-1,4-dihydropyridine were obtained and the direction of heterocyclization upon the reaction of these diketones with primary amines containing an additional nucleophilic site was elucidated. The facile free-radical cleavage of the angular tert-butyl group was demonstrated.     

Mutual Kinetic Resolution in Aldol Condensation between 2-Phenylpropanal and 4,5-Dihydro-5-methyl-2-(trimethylsiloxy)-3-(trimethylsilyl)furan

The titanium(IV) chloride-mediated aldol condensation between title compounds proceeds with high diastereoselectivity (Cram) to give $\text{3a}$ exclusively (99% purity).     

Complexation of silver nitrate with imidazolidine-2-thione and its derivatives

The reaction of AgNO₃ with imidazolidine-2-thione (Imt), 1,3-diazinane-2-thione (Diaz) and their derivatives yields complexes of stoichiometry [AgLNO₃] (where L=Imt or Diaz and their derivatives). The C-2 resonances of the Diaz complexes were shifted more from the free ligand positions compared to the Imt complexes, suggesting that the former bind more strongly to Ag¹ than the latter. TMC 2670