1,720,971 research outputs found
Palladium-catalyzed cyclization of N-n-butyl, N-(o-iodobenzyl)-3-butenamides: six- versus seven- and eight-membered ring formation
No full textSynthesis of 1,2,3,4-tetrahydroisoquinolines and 2,3,4,5-tetrahydro-1H-2 benzazepines combining sequential palladium-catalysed ortho alkylation/vinylation with aza-Michael addition reactions
No full textChemInform Abstract: Efficient Synthesis of aza-Heterocycles by a Domino Process Using an Inter- and an Intramolecular Heck Reaction.
No full textNew catalytic methods for the synthesis of selectively substituted aromatics through palladacycles
No full textSynthesis of a 4-Vinyltetrahydrocarbazole by Palladium-Catalyzed Asymmetric Allylic Alkylation of Indole-Containing Allylic Carbonates
No full textPalladium-catalyzed intramolecular asymmetric allylic alkylation was used for the first time to prepare 4-vinyltetrahydrocarbazole 3. Suitable indole-containing allylic carbonates were synthesized and cyclized in the presence of a chiral catalyst formed in situ from Pd(OAc)2 and members of the PhthalaPhos ligand library (i.e., 1,1′-bi-2-naphthol-monophosphites possessing a phthalic acid diamide group). The use of a stable and readily available palladium source such as Pd(OAc)2 reduced in situ by the phosphite to form the Pd0 catalyst allowed better and more reproducible results to be obtained relative to the results achieved by using [Pd2(dba)3·CHCl3] (dba = dibenzylideneacetone) and [Pd(allyl)Cl]2. A ligand screening led to identification of the best ligand [(S)-L1], which, after optimization of the reaction parameters, gave product 3 with 75 % ee. Remarkably, the reaction turned out to be stereodivergent: by using ligand (S)-L1, the absolute configuration of product 3 was found to depend on the geometry of the substrate's double bond [(E)-substrate → (S)-3, (Z)-substrate → (R)-3]
Transmission of substituent effects through the methyleneamino group N=CH : Aldehyde phenylhydrazones and conjugate anions
No full textPalladium-catalysed synthesis of enantiopure 1,2,4,5-tetrahydro-1,4-benzodiazepin-3-(3H)-one derivatives
No full textSequential unsymmetrical aryl coupling of o-substituited aryl iodides with o-bromophenols and reaction with olefins: palladium-catalyzed synthesis of 6H-dibenzopyran derivatives
No full textDibenzopyran derivatives are prepared by palladium- and norbornene-catalyzed reaction of aryl
iodides, o-substituted with electron-releasing substituents, o-bromophenols, and activated
alkenes
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