نتایج جستجو برای: diamines
تعداد نتایج: 2106 فیلتر نتایج به سال:
Anticancer approaches may employ change of molecular structure to enhance preventive influence of chemical agents. The present examination concerned the potential anticancer impact of modified heterocyclic compounds. A strategy was developed to combine tetrazole moieties from different diamines with 2-aminobenzoic and substituted benzoyl chloride compounds with attention to synthesis, character...
Tetraphenyladamantane-based porous poly(Schiff base)s with BET surface area (>1000 m(2) g(-1)), CO2 uptake (15 wt%, 273 K/1 bar) and H2 uptake (1.26 wt%, 77 K/1 bar) were synthesized. The structure-directing effect of isomers of phenyl diamines on building porous architecture was investigated.
Large macrocycles containing imine and borasiloxane links are obtained in polycondensation reactions of 4-formylbenzeneboronic acid, t-Bu(2)Si(OH)(2), and diamines. The multicomponent reactions can be performed in solution or--advantageously--by mechanochemical syntheses in a ball mill.
2,4,6-Trichloro-1,3,5-triazine (TCT) efficiently catalyzed the condensation reactions between 1,2-diamines and various enolizable ketones to afford 1,5-benzodiazepines in good to excellent yields. Simple and mild reaction conditions, the use of a cheap catalyst and easy workup and isolation are notable features of this method.
In this paper we report the binding properties, by combined 1H NMR, optical absorption, and fluorescence studies, of a molecular tweezer composed two Zn(salen)-type Schiff-base units connected flexible spacer, towards series ditopic diamines having strong Lewis basicity, with different chain length rigidity. Except for 1,2-diaminoethane, in all other cases formation stable 1:1 acid-base adducts...
Chiral C₂-symmetric diamines have emerged as versatile auxiliaries or ligands in numerous asymmetric transformations. Chiral 2,2'-bispyrrolidine-based salan ligands were prepared and applied to the asymmetric aryl transfer to aldehydes with arylboronic acids as the source of transferable aryl groups. The corresponding diarylmethanols were obtained in high yields with moderate to good enantiosel...
Amination of enecarbamates with dibenzylazodicarboxylate and oxygenated nucleophiles in the presence of a catalytic amount of chiral phosphoric acid afforded optically active stable precursors of α-hydrazinoimines, which were reduced or oxidized, respectively, to vicinal diamines or α-amino acid precursors with excellent yield and enantioselectivity.
Organocatalysts containing primary-secondary diamines based on bispidine have been developed to catalyze the asymmetric Michael addition of ketones to alkylidene malonates and nitroalkenes. The corresponding products were obtained in high yields (up to 99%) with high diastereoselectivities (up to 99:1) and high enantioselectivities (up to 97% ee) under mild conditions using either environmental...
Highly efficient asymmetric aldol reactions between α,β-unsaturated keto esters and acyclic ketones catalyzed by chiral diamines are reported. The corresponding products were obtained in excellent yields with excellent enantioselectivities. The absolute configuration for the product was determined by X-ray analysis. A variety of substrates were tolerable in the present catalytic system.
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