نتایج جستجو برای: disubstituted urea
تعداد نتایج: 40692 فیلتر نتایج به سال:
A stereoselective hypervalent iodine-promoted oxidative rearrangement of 1,1-disubstituted alkenes has been developed. This practically simple protocol provides access to enantioenriched α-arylated ketones without the use of transition metals from readily accessible alkenes.
A convenient methodology for the highly stereoselective synthesis of unsymmetrical (1E,3E)-1,4-disubstituted 1,3-dienes based on palladium-catalyzed Hiyama cross-coupling reaction of 1-(triethoxysilyl)-substituted buta-1,3-dienes with aryl iodides is reported.
A facile, highly regio- and enantioselective amino-thiocarbamate-catalyzed bromolactonization of cis-1,2-disubstituted olefinic acids has been developed. The use of the enantio-enriched lactones in the synthesis of chiral synthetic intermediates is also demonstrated.
Novel disubstituted EDOT monomers were synthesized in good yields from 3,4-dimethoxythiophene and (chiral) glycols by transetherification. The stereochemistry of the monomers affects the electronic properties of the corresponding chiral PEDOT derivatives.
Condensation of 4-amino-2,3-dimethyl-1-phenyl-3-pyrazoline-5-one with different aromatic and heterocyclic aldehydes in dry toluene give schiff bases 3(a-g), which on reaction with thioglycolic acid and thiolactic acid in dry toluene give the corresponding 2,3-disubstituted-4-thiazolidinones 4(a-g) and 2,3-disubstituted-5-methyl-4thiazolidinones 5(a-g). The methylene carbon atom at the position ...
Chiral diols with three contiguous stereocenters were synthesized by a highly enantioselective ruthenium-catalyzed asymmetric hydrogenation of racemic α,α'-disubstituted cycloketones involving dynamic kinetic resolution. This new catalytic asymmetric method provides a concise route to the alkaloid (+)-γ-lycorane.
A library of 4,5-disubstituted-2-aminoimidazoles was synthesized using a nitroenolate route and then screened for antibiofilm and antimicrobial activity. These compounds displayed notable biofilm dispersal and planktonic microbicidal activity against various Gram-positive and Gram-negative bacteria.
The first organocatalytic "anti-Michael" reaction of cyclic-beta-ketoesters to unsaturated double bonds is described in a highly asymmetric version leading to the synthesis of alpha,alpha'-disubstituted branched double bonds as optically active Baylis-Hillman-like adducts.
Bleach oxidizes trimethylsilyl cyanide to generate an electrophilic cyanating reagent that readily reacts with an amine nucleophile. This oxidative N-cyanation reaction allows for the preparation of disubstituted cyanamides from amines without using highly toxic cyanogen halides.
The regioselective Stille cross-coupling reactions of 3-tri-n-butylstannyl-1-trimethylsilyl-1-propyne demonstrate isomerization following the initial transmetalation step resulting in allenyl palladium intermediates for reductive coupling to yield conjugated 1,1-disubstituted allenylsilanes.
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید