Stereoselective one-pot, three-component synthesis of 4-amidotetrahydropyran

The reaction of aldehyde with allylsilane in acetonitrile mediated by boron trifluoride etherate generated 4-aminotetrahydropyrans in good yields. The product is highly stereoselective.     

Stereoselective synthesis of 4-hydroxymethyl-1,3-oxazolidin-2-one derivatives from novel 2-hydroxymethylaziridines

A stereoselective and simple method for the synthesis of trans-2-hydroxymethyl-N-alkyl-1,3-oxazolidin-2-ones is described. The synthesis involved the reduction of trans-aziridine-2-carboxylates with LiAlH₄, followed by a ring opening and a cyclization reaction in the presence of methyl chloroformate to afford the target trans-oxazolidinones in completely regio- and stereoselective process. A plausible reaction mechanism has been proposed involving an S_N1 pathway and a detailed computational study of this mechanistic process has been carried out using theoretical calculations.     

Efficient synthesis of pyranochromene derivatives via three-component reaction of 4-hydroxy-6-methylpyran-1-one with aromatic aldehydes and cyclic 1,3-diketone catalyzed by ZnO nanoparticles

Russian Journal of General Chemistry - Three-component reaction of 4-hydroxy-6-methylpyran-1-one with aromatic aldehydes and cyclic-1,3-diketone catalyzed by ZnO nanoparticles under solvent-free...     

Iodine-catalyzed one-pot three-component synthesis of homoallyl benzyl ethers from aldehydes

Iodine has been found to be an effective catalyst for one-pot synthesis of homoallyl benzyl ethers under mild reaction conditions. Various homoallyl benzyl ethers were synthesized in moderate to high yield by three-component condensation of aldehydes, benzyloxytrimethylsilane, and allyltrimethylsilane in presence of iodine (10 mol %) in dichloromethane at 0 °C.     

Stereoselective synthesis of vicinal aminodiols,diamines and diaminols by the use of enantiopure aldehydes in the three-component aromatic Mannich-type reaction

A short and stereoselective synthesis of vicinal aminodiols, diamines and diaminols obtained in good yields, through a three-component aromatic Mannich-type reaction, is reported. Enantiopure aldehydes containing stereogenic centres and functionalized with variously protected amino and hydroxy groups successfully afforded enantiopure aminoalkylnaphthols. Conformational analysis, compared with ¹H NMR data of the products obtained, allows the attribution of the absolute configuration, also confirmed by X-ray analysis.     

Design,synthesis and antifungal activity of novel selenochroman-4-one derivatives

A series of novel selenochroman-4-one derivatives bearing semicarbazone or nitrogen heterocycle was designed, synthesized, tested antifungal activity and characterized via ¹H-NMR, ¹³C-NMR, and HRMS. The design of the compounds is based on the principle of molecule hybrid and bioisosterism. We aimed at attaching semicarbazones or nitrogen heterocycle to the selenochroman-4-one for enhancing antifungal activity. The antifungal activity of target compounds was evaluated using the microdilution broth method in vitro test. Bioassay results indicated that some of the derivatives displayed good fungistatic activity on Candida zeylanoides, Candida albicans, Cryptococcus neoformans, resistant to fluconazole strain 103 (Candida albicans), resistant to fluconazole strain 100 (Candida albicans) and strain SC5314 (Candida albicans). All the compounds exhibit antifungal activities against the tested funguses in different levels, among them, 7 compounds of antifungal activity against several funguses is better than that of the control drug fluconazole. Based on the results, preliminary structure activity relationships (SARs) were summarized to serve as a foundation for further investigation.     

One-pot reductive mono-N-alkylation of aniline and nitroarene derivatives using aldehydes

One-pot reductive mono-N-alkylation of aniline and nitroarene derivatives using various aldehydes by Pd/C catalyst in aqueous 2-propanol solvent with ammonium formate as in situ hydrogen donor is illustrated. The reaction proceeded smoothly and selectively with excellent yield at room temperature. Our protocol presents a facile, economical, and environmentally benign alternative for reductive amination.     

Stereoselective synthesis of tricyclic derivatives of 2-amino-1-pyrrolin-5-one dimethyl acetals

Reactions of a tetracyanobicycloalkene (1) with methanol and ethylene glycol give derivatives of 2-aminopyrrolin-5-one (2 and 3), and acid hydrolysis of3 gives an imide (4). According to an X-ray structural investigation, acis orientation of the heterocycle (with respect to the C=C bond) is realized in2; in the case of4, thecis/trans ratio of the isomers in the crystal and solution is 21.Signals overlap and are lost in the background noise.Translated fromIzvestiya Akademii Nauk. Seriya Khimlcheskaya, No. 3, pp. 534–538, March, 1993.     

Iodine-catalyzed three-component reaction of quinazoline-2,5-diones with aldehydes and styrenes for the synthesis of allylamine derivatives

Iodine-catalyzed three component reaction of quinazoline-2,5-diones, aldehydes, and styrenes provides allylamine derivatives was described. Both paraformaldehyde and ethyl glyoxalate can be applied in this reaction with simple styrenes with high regioselectivity.     

Catalyst-free three-component approach to efficient synthesis of chromeno[4,3-b]pyrrol-4(1H)-one derivatives

A mild, efficient, and environmentally benign one-pot synthesis of functionalized chromeno[4,3-b]pyrrol-4(1H)-ones by a three-component domino reaction of 4-aminocoumarins, arylglyoxal monohydrates, and 1,3-dicarbonyl compounds in refluxing ethanol without the use of catalyst is reported. The present protocol features operational simplicity, short reaction time, good yields, and the absence of aqueous workup procedure and chromatographic separation.     

Simple synthesis of 7H-phenaleno[1,2-b]furan-7-one derivatives by one-pot, three-component reactions

The reaction of alkyl isocyanides with various aldehydes and 3-hydroxy-1 H-phenalene-1-one is described. The protocol offers facile and efficient synthesis of biologically interesting 9-(alkyl or arylamino)-7 H-phenaleno[1,2- b]furan-7-one derivatives from readily available starting materials in high yields.     

Regioselective Friedel-Crafts acetylation of 5-hydroxyindole derivatives: synthesis of 4H-pyranoindol-4-one derivatives

The Friedel-Crafts acetylation of 5-hydroxyindole derivativesla-c regioselectively produced 6-acetyl-5-hydroxy-indole derivatives2a-c which were condensed with cinnamic acid using POC1₃ and dry pyridine to afford 5-cinnamoyloxy-6-acetyl-indoles3a-c. These upon Baker-Venkataraman transformation furnished 6-cinnamoylacetyl-5-hydroxyindoles4a-c which were cyclised separately with AcOH/HCl and Ac₂O/AcONa to 4H-pyrano-(2,3-f)indol-4-one derivatives5a-c and6a-c respectively.     

Stereoselective three-component one-stage synthesis of 2-pyrrolidinecarboxylic acid polyfunctional derivative

A reaction of racemoc methyl 4-oxo-2-phthalimidobutanoate, diethyl aminomalonate, and phenyl vinyl sulfone in the presence AgOAc occurred stereospecifically to form tetrasubstituted pyrrolidine including structural elements of all three initial compounds. The relative stereochemistry of the asymmetrical carbon atoms in the molecule was established by XRD analysis, and it coincided with two stereogenic centers in the left part of kaitocephalin molecule. Therefore the developed three-component process can be recommended for an effective total synthesis of kaitocephalin.     

AcOH catalyzed three-component synthesis of spirooxindole derivatives

An efficient one-pot synthesis of hereto unknown indenoquinoline-spirooxindole derivatives by a three-component reaction of isatins, indan-1,3-dione, and 3-aminocyclohex-2-enone under the catalysis of acetic acid was developed. The procedure had the advantages of simplicity and efficiency.     

Stereoselective synthesis of 1,3-substituted tetrahydroisoquinolines through palladium-catalyzed three-component reaction

Chiral 1,3-substituted 1,2,3,4-tetrahydroisoquinolines have been synthesized in acceptable yield and diastereoselectivity through a three component reaction, starting from aromatic halides, enantiopure bromoalkyl derivatives and methyl acrylate, under palladium catalysis.     

One-pot three-component synthesis of the spiroacenaphthylene derivatives

A facile and efficient one-pot three-component synthesis of the spiroacenaphthylene derivatives was achieved, via the reaction of acenaphthequinone, malononitrile/ethylcyanoacetate and various reagents including α-methylencarbonyl compounds/enols.     

Gold-catalyzed three-component annulation: efficient synthesis of highly functionalized dihydropyrazoles from alkynes, hydrazines, and aldehydes or ketones

Polysubstituted dihydropyrazoles were directly obtained by a gold-catalyzed three-component annulation. This reaction consists of a Mannich-type coupling of alkynes with N,N'-disubstituted hydrazines and aldehydes/ketones followed by intramolecular hydroamination. Cascade cyclization using 1,2-dialkynylbenzene derivatives as the alkyne component was also performed producing fused tricyclic dihydropyrazoles in good yields.