Results 21 to 30 of about 27,991 (255)
Molecules, 2022 The AgOAc-catalysed reaction of 3-nitro-2-phenyl-2H-chromenes with stabilized azomethine ylides generated from the imines based on methyl glycinate and arylaldehydes leads to a mixture of endo and endo’ isomers of the corresponding chromeno[3,4-c ...
Ivan A. Kochnev +6 more
doaj +1 more source
Communications Chemistry, 2023 Polycyclic N-heterocycles are important structural motifs commonly found in bioactive compounds, however, their selective construction via the cyclization of allenynes remains challenging yet highly desirable.
Kua-Fei Wei +6 more
doaj +1 more source
Molecules, 2021 1,3-Dipolar cycloaddition reactions of 2-substituted 5-R-3-nitropyridines and isomeric 3-R-5-nitropyridines with N-methyl azomethine ylide were studied. The effect of the substituent at positions 2 and 5 of the pyridine ring on the possibility of the [3 ...
Maxim A. Bastrakov +3 more
doaj +1 more source
Enantioselective Access to Trifluoromethylated Spirocyclopropyl Heterocycles. [PDF]
Adv Sci (Weinh)We report a rhodium‐catalyzed asymmetric [2+1] spirocyclopropanation of methylene azacycles with trifluoromethyl carbenes in situ derived from fluoroalkyl triftosylhydrazones. ABSTRACT Chiral spirocyclopropyl heterocycles have emerged as privileged three‐dimensional structural motifs in medicinal chemistry.
Zhu Y +9 more
europepmc +2 more sources
Beilstein Journal of Organic Chemistry, 2021 A new highly diastereoselective synthesis of the polyhydroxylated pyrrolidine alkaloid (±)-codonopsinol B and its N-nor-methyl analogue, starting from achiral materials, is presented.
Lukáš Ďurina +7 more
doaj +1 more source
Diastereoselective Preparation of Azetidines and Pyrrolidines
, 2016 Iodine-mediated cyclization of homoallyl amines at room temperature delivered cis-2,4-azetidine through a 4-exo trig cyclization. Isomerization of iodo-azetidines to cis-pyrrolidines could be achieved by heating, with complete stereocontrol. The relative
John S. Fossey (1392100) +2 more
core +3 more sources
Synthesis and Biological Study of Some New Pyrrolidines [PDF]
مجلة التربية والعلم, 2007 A series of Schiff bases N-Arylidene benzylamie (1-6) have been prepared, and through 1,3-anionic cycloaddition under strong basic conditions were added to benzoquinone to afford the fused new pyrrolidines (7-12).
A.J. Al-Hamdany +2 more
doaj +1 more source
Molecules, 2010 The synthesis of a small library of dihydrouracils spiro-fused to pyrrolidines is described. These compounds are synthesized from b-aryl pyrrolidines, providing products with the 2-arylethyl amine moiety, a structural feature often encountered in ...
Daniel Blanco-Ania +5 more
doaj +1 more source
Stable D-xylose ditriflate in divergent syntheses of dihydroxy prolines, pyrrolidines, tetrahydrofuran-2-carboxylic acids, and cyclic sugar -amino acids [PDF]
, 2022 Double nucleophilic displacement of a sugar D-xylose ditriflate derived from diacetone-D-glucose by amines, water and alkyl cyanoacetates gave a series of bicyclic divergent intermediates for the synthesis of a wide range of highly functionalized targets,
Soufian, El Ayadi +8 more
core +1 more source
, 2016 Highly enantioselective syntheses of (S)-2-aryl-Boc-pyrrolidines (Boc = tert-butoxycarbonyl) can be achieved by treatment of the corresponding (arylmethyl)(3-chloropropyl)-Boc-amines with s-BuLi/(−)-sparteine. The reactions are solvent dependent with the
Steven Lee (72507) +2 more
core +2 more sources