نتایج جستجو برای: unsymmetrical anhydrides
تعداد نتایج: 3777 فیلتر نتایج به سال:
A facile synthesis of a series of benzene ring acylated analogues of harmaline has been achieved by Friedel-Crafts acylation under solvent-free conditions at room temperature using acyl halides/acid anhydrides and AlCl3. The reaction afforded 10- and 12-acyl analogues of harmaline in good yield, along with minor quantities of N-acyl-tryptamines and 8-acyl analogues of N-acyltryptamines.
A new method for the enantioselective reductive coupling of aryl alkenes with activated carboxylic acid derivatives via copper hydride catalysis is described. Dual catalytic cycles are proposed, with a relatively fast enantioselective hydroacylation cycle followed by a slower diastereoselective ketone reduction cycle. Symmetrical aryl carboxyclic anhydrides provide access to enantioenriched α-s...
An efficient carboesterification of alkenes with anhydrides promoted by MnO2 has been developed to afford functionalized γ-lactones in good to excellent yields. This method shows a broad substrate scope and provides a valuable and convenient synthetic tool for constructing γ-lactones.
Mechanisms of double carbonylation reactions catalyzed by palladium complexs to give a-keto amides and a-keto esters, stoichiometric double carbonylation of ally1 carbonates, and cyclization carbonylation . of 3-butenoic acid to give cyclic anhydrides are discussed as combination of elementary processes of organometallic reactions.
Ni-catalyzed ketone formation through mild reductive coupling of a diverse set of unactivated alkyl bromides and iodides with particularly aryl acid anhydrides was successfully developed using zinc as the terminal reductant. These conditions also allow direct coupling of alkyl iodides with aryl acids in the presence of Boc(2)O and MgCl(2).
The ring-opening of N-tosylaziridines with various acid anhydrides catalyzed by 5 mol % of 1,5,7-triazabicyclo[4,4,0]dec-5-ene (TBD) afforded the corresponding β-amino esters in excellent yields under mild reaction conditions. Polymer-supported catalyst, PS-TBD also acts as a good catalyst for this reaction. PS-TBD was easily recovered and reused with minimal loss of activity.
Synthesis of unsymmetrical and bifunctional building blocks based on 1,1,3,3-tetramethyldisiloxane is presented which allows compounds with a wide spectrum reactive groups bonded to alkenes alkynes be obtained.
Unsymmetrical ditopic ligands can self-assemble into reduced-symmetry Pd2L4 metallo-cages with anisotropic cavities, implications for high specificity and affinity guest-binding. Mixtures of cage isomers form, however, resulting in undesirable system heterogeneity. It is paramount to be able design components that preferentially form a single isomer. Previous data suggested computational method...
For the first time, ball milling is used in functionalization of silsesquioxanes. The solid-state nucleophilic addition aminopropylisobutyl POSS to cyclic anhydrides leads silsesquioxane amic acids virtually quantitative yields without use a solvent. reactions are easily scalable and can be adopted multigram quantities.
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید