نتایج جستجو برای: preparation of ketones
تعداد نتایج: 21170795 فیلتر نتایج به سال:
The cadmium reagent may be prepared from a lithium derivative instead of a Grignard reagent, if desired (19). This sequence may be carried through in a few hours without isolation of intermediates; however, the general utility of the method mas not recognized for several years, possibly on account of experimental difficulties encountered in carrying out these reactions (cf. Section IV). At leas...
New synthetic technologies for the preparation and elaboration of alpha-tosyloxy ketones in solution- and on solid-phase are described. Both olefins and ketones serve as precursors to these relatively stable chemical entities: olefins via a novel one-pot epoxidation, arylsulfonic acid displacement, and oxidation sequence, and ketones by direct exposure to arylsulfonic acids in the presence of d...
A simple method for the preparation of aryl methyl ketones is reported. The transformation involves the Pd-catalyzed coupling of an acyl anion equivalent, acetyltrimethylsilane, with aryl bromides to afford the corresponding acetylated arenes in synthetically useful yields. The methodology is tolerant of heterocycles and provides a new method for arene functionalization.
An unprecedented approach that enables the direct and selective preparation of 1,5-disubstituted 1,2,3-triazoles from abundantly available building blocks such as primary amines, enolizable ketones and 4-nitrophenyl azide as a renewable source of dinitrogen via an organocascade process has been developed. Furthermore, this efficient methodology also enables the synthesis of fully functionalized...
A novel radical phosphinylation of α,α-diaryl allylic alcohols with arylphosphine oxides was described for the direct preparation of α-aryl-β-phosphinylated carbonyl ketones in medium to good yields via 1,2-aryl migration. In this reaction, formation of new C(Ar)-C(sp(3)) and C(sp(3))-P bonds was observed.
A complement to the classic three-component Mannich reaction, the redox-Mannich reaction, utilizes the same starting materials but incorporates an isomerization step that enables the facile preparation of ring-substituted β-amino ketones. Reactions occur under relatively mild conditions and are facilitated by benzoic acid.
Reactions of N-isocyaniminotriphenylphosphorane with a cyclic ketone in the presence of ferrocene carboxylic acid proceeded smoothly at room temperature and in neutral conditions to afford ferrocene-containing 1,3,4-oxadiazole derivatives in high yields. The reaction proceeded smoothly and cleanly under mild conditions and no side reactions were observed. The structures of the products were ded...
An effective and convenient method has been developed for the preparation of 2 or 2,4-substituted α-carbolines via a one-pot tandem reaction of α,β-unsaturated ketones with 2-nitrophenylacetonitrile in the presence of zinc dust, acetic acid and triethylamine. This protocol presents a simple, rapid and pot/step economical strategy for preparing biologically interesting α-carbolines with moderate...
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