نتایج جستجو برای: alkene
تعداد نتایج: 1831 فیلتر نتایج به سال:
The intermolecular addition of N-H bonds to unactivated alkenes remains a challenging, but desirable, strategy for the synthesis of N-alkylamines. We report the intermolecular amination of unactivated α-olefins and bicycloalkenes with arylamides and sulfonamides to generate synthetically useful protected amine products in high yield. Mechanistic studies on this rare catalytic reaction revealed ...
Due to the profound extent to which natural products inspire medicinal chemists in drug discovery, there is demand for innovative syntheses of these often complex materials. This article describes the synthesis of tricarbocyclic natural product architectures through an extension of the enantioselective Birch-Cope sequence with intramolecular Friedel-Crafts alkylation reactions. Additionally, pa...
Hydrozirconation of 1-hexyne, the addition to in situ prepared N-acyliminium species, and ring-closing metathesis (RCM) were key steps in the preparation of a tricyclic isoindolinone scaffold. An unusual alkene isomerization process during the RCM was identified and studied in some detail. Chemical diversification for library synthesis was achieved by a subsequent alkene epoxidation and zinc-me...
Silicon nanoparticles were prepared and functionalized with alkene-terminated poly(ethylene oxide) to impart amphiphilic solution properties to the particles.
Rhodium-alkene complexes of the pincer ligand ?3-C5H3N-2,6-(OPiPr2)2 (PONOP-iPr) have been prepared and structurally characterized: [Rh(PONOP-iPr)(?2-alkene)][BArF4] [alkene = cyclooctadiene (COD), norbornadiene (NBD), ethene; ArF 3,5-(CF3)2C6H3]. Only one these, alkene COD, undergoes a reaction with H2 (1 bar), to form [Rh(PONOP-iPr)(?2-COE)][BArF4] (COE cyclooctene), while others show no sign...
Typically, Povarov reactions of imines derived from aromatic amines and aromatic aldehydes show poor exo/endo-stereoselectivity and to date no data is available on the regioselectivity of the cyclisation when 3-substituted imines are employed. We have demonstrated that reaction using acyclic enamides as the alkene component with 3-nitro substituted imines is completely regioselective and gave o...
Two reaction strategies are developed to promote the highly selective 1,3-isomerization of a variety of allylic alcohols using O3ReOSiPh3 as a catalyst. The first strategy utilizes substrates whose 1,3-regioisomer contains a conjugated alkene, which relies on thermodynamics to obtain high selectivity. The second strategy employs N,O-bis(trimethylsilyl)acetamide as an additive to selectively and...
Using rational ligand design, we have developed of a second-generation ligand, bis(3,5-di-tert-butylphenyl)(tert-butyl)phosphine, for the preparation of allylsilanes using the palladium-catalyzed silyl-Heck reaction. This new ligand provides nearly complete suppression of starting material alkene isomerization that was observed with our first-generation catalyst, providing vastly improved yield...
Allylrhodium species derived from δ-trifluoroboryl β,γ-unsaturated esters undergo chain walking towards the ester moiety. The resulting allylrhodium species react with imines to give products containing two new stereocenters and a Z-alkene. By using a chiral diene ligand, products can be obtained with high enantioselectivities, where a pronounced matched/mismatched effect with the chirality of ...
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