نتایج جستجو برای: amides
تعداد نتایج: 3739 فیلتر نتایج به سال:
A direct asymmetric hydrogenation of unprotected enamino esters and amides is described. Catalyzed by Rh complexes with Josiphos-type chiral ligands, this method gives beta-amino esters and amides in high yield and high ee (93-97% ee). No acyl protection/deprotection is required.
a highly efficient procedure for the preparation of n,n'-alkylidenebisamides in the presence of bf3.sio2 as a catalyst is described. n,n'-alkylidenebisamides have been prepared via one-pot three-component condensation reaction of various aldehydes and amides. all of the reactions proceeded in high yields and in moderately short reaction times.
The heteroleptic calcium amides [{ArNC(Me)CHC(Me)NAr}Ca(NR(2))(THF)] (Ar=2,6-di-iso-propylphenyl, R=SiMe(3), Ph) and the homoleptic heavier alkaline earth amides, [M{N(SiMe(3))(2)}(2)] (M=Ca, Sr and Ba) are reported as pre-catalysts for the hydroamination of isocyanates.
The arylation of secondary acyclic amides has been achieved with diaryliodonium salts under mild and metal-free conditions. The methodology has a wide scope, allows synthesis of tertiary amides with highly congested aryl moieties, and avoids the regioselectivity problems observed in reactions with (diacetoxyiodo)benzene.
The reaction of tertiary, secondary and benzylic alcohols with different nitriles in the presence of alumina-methanesulfonic acid (AMA) as a new reagent affords the corresponding amides in good yields (Table 1, 2). Conversion of 2,6-bis(hydroxymethyl)-4-halo anisoles into corresponding diamides in the range of 68-76% yields (Table 3) are also included in this paper.
zn/acoh on silica gel converts a range of structurally different sulfoxides to their corresponding thioethers in excellent yields under microwave irradiation. it has been found that chemoselective deoxygenation of sufoxides can be achieved in the presence of other reducible functional groups such as acetals, acids, amides, esters, ketones and nitriles.
pyrazine derivatives are important class of compounds with diverse biological and cytotoxic activities and clinical applications. in this study, b3 p 86 / 6 – 31 + + g * was used to compute and map the molecular surface electrostatic potentials of a group of substituted amides of pyrazine-2-carboxylic acids to identify common features related to their subsequent cytotoxicities. several statisti...
N-Protonation of amides is critical in numerous biological processes, including amide bonds proteolysis and protein folding as well as in organic synthesis as a method to activate amide bonds towards unconventional reactivity. A computational model enabling prediction of protonation at the amide bond nitrogen atom along the C-N rotational pathway is reported. Notably, this study provides a blue...
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