Results 51 to 60 of about 28,644 (231)
Efficient Diastereo- and Enantioselective Synthesis of exo-Nitroprolinates by 1,3-Dipolar Cycloadditions Catalyzed by Chiral Phosphoramidite⋅Silver(I) Complexes [PDF]
, 2014 Chiral complexes formed by privileged phosphoramidites and silver triflate or silver benzoate are excellent catalysts for the general 1,3-dipolar cycloaddition between azomethine ylides generated from α-amino acid-derived imino esters and nitroalkenes ...
Castelló Moncayo, Luis Miguel +5 more
core +2 more sources
Molecules, 2023 An unprecedented oxidative cyclodimerization reaction of 2H-azirine-2-carboxylates to pyrimidine-4,6-dicarboxylates under heating with triethylamine in air is described. In this reaction, one azirine molecule undergoes formal cleavage across the C-C bond
Timofei N. Zakharov +4 more
doaj +1 more source
Metal-free α-amination of secondary amines: Computational and experimental evidence for azaquinone methide and azomethine ylide intermediates [PDF]
, 2013 We have performed a combined computational and experimental study to elucidate the mechanism of a metal-free α-amination of secondary amines. Calculations predicted azaquinone methides and azomethine ylides as the reactive intermediates and showed that ...
Dieckmann, A. +5 more
core +1 more source
CHIMIA, 1991 Azomethine-imines are well known to undergo ground-state 1,3-dipolar cycloaddition reactions with olefins or acetylenes, leading thereby to five-membered heterocyclic systems. When excited by UV light, some of these 1,3-dipolar azomethine-imines
Jacques Streith
doaj +2 more sources
SynOpen, 2021 Regio- and stereoselective methods for the synthesis of 6′-trifluoro(trichloro)methyl substituted spiro[acenaphthylene-1,11′-chromeno[3,4-a](thia)pyrrolizidin]-2-ones and spiro[acenaphthylene-1,12′-chromeno[3,4-a]indolizidin]-2-ones have been developed ...
Igor B. Kutyashev +6 more
doaj +1 more source
Binap-silver-catalyzed enantioselective multicomponent 1,3-dipolar cycloaddition of azomethines ylides derived from ethyl glyoxylate [PDF]
, 2015 The enantioselective binap–silver catalyzed multicomponent 1,3-dipolar cycloaddition using ethyl glyoxylate, phenylalanine ethyl ester, and maleimides is described. The employment of basic silver carbonate allows the reaction to take place in the absence
Mancebo Aracil, Juan +2 more
core +2 more sources
Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds
Beilstein Journal of Organic Chemistry, 2023 The [3 + 2] cycloadditions of stabilized azomethine ylides (AMYs) derived from amino esters are well-established. However, the reactions of semi-stabilized AMYs generated from decarboxylative condensation of α-amino acids with arylaldehydes are much less
Xiaofeng Zhang, Xiaoming Ma, Wei Zhang
doaj +1 more source
Frontiers in Chemistry, 2022 A short and efficient multicomponent sequence for synthesizing fused novel polyheterocyclic chromeno spiro-pyrrolidine oxindoles via 1,3-dipolar cycloaddition reaction mediated by reactive azomethine ylides catalyzed by the Graphene Oxide (GO) is ...
Vipin Singh +2 more
doaj +1 more source
Synthesis of benzopyranopyrrolidines via 1,3-dipolar cycloaddition of nonstabilized azomethine ylides with 3-substituted coumarins [PDF]
, 2013 A three-component reaction of 3-substituted coumarins with N-alkyl-α-amino acids and aldehydes gave 1-benzopyrano[3,4-c]pyrrolidines as a result of a 1,3-dipolar cycloaddition of an intermediate nonstabilized azomethine ylide at the double bond of the ...
Moshkin, V. S. +2 more
core +1 more source
Molecules, 2022 The enantioselective 1,3-dipolar cycloaddition between imino esters and (Z)-nitroalkenes bearing a masked amino group in the β-position was studied using several chiral ligands and silver salts.
Eduardo García-Mingüens +5 more
doaj +1 more source