14004-15-0Relevant academic research and scientific papers
Oxidative cyclizations in a nonpolar solvent using molecular oxygen and studies on the stereochemistry of oxypalladation
Trend, Raissa M.,Ramtohul, Yeeman K.,Stoltz, Brian M.
, p. 17778 - 17788 (2007/10/03)
Oxidative cyclizations of a variety of heteroatom nucleophiles onto unactivated olefins are catalyzed by palladium(II) and pyridine in the presence of molecular oxygen as the sole stoichiometric oxidant in a nonpolar solvent (toluene). Reactivity studies of a number of N-ligated palladium complexes show that chelating ligands slow the reaction. Nearly identical conditions are applicable to five different types of nucleophiles: phenols, primary alcohols, carboxylic acids, a vinylogous acid, and amides. Electronrich phenols are excellent substrates, and multiple olefin substitution patterns are tolerated. Primary alcohols undergo oxidative cyclization without significant oxidation to the aldehyde, a fact that illustrates the range of reactivity available from various Pd(II) salts under differing conditions. Alcohols can form both fused and spirocyclic ring systems, depending on the position of the olefin relative to the tethered alcohol; the same is true of the acid derivatives. The racemic conditions served as a platform for the development of an enantioselective reaction. Experiments with stereospecifically deuterated primary alcohol substrates rule out a "Wacker-type" mechanism involving anti oxypalladation and suggest that the reaction proceeds by syn oxypalladation for both mono- and bidentate ligands. In contrast, cyclizations of deuterium-labeled carboxylic acid substrates undergo anti oxypalladation.
Investigation of the Montmorillonite clay-catalyzed [1,3] shift reaction of 3-methyl-2-butenyl phenyl ether
Dintzner, Matthew R.,Morse, Kara M.,McClelland, Kristen M.,Coligado, Deborah M.
, p. 79 - 81 (2007/10/03)
The [1,3] shift reaction of 3-methyl-2-butenyl phenyl ether was catalyzed more effectively by Montmorillonite K10 clay than Montmorillonite KSF clay, and proceeded with greatest ortho-selectivity in carbon tetrachloride at room temperature.
A new direct allylation of the aromatic compounds with allylic chlorides catalyzed by indium metal
Lim, Hwan Jung,Keum, Gyochang,Kang, Soon Bang,Kim, Youseung,Chung, Bong Young
, p. 1547 - 1550 (2007/10/03)
A new method of the direct allylation reaction for the aromatic compounds with allylic chlorides using a catalytic mount of indium in the presence of CaCO3/4A molecular sieves was developed.
COPPER PROMOTED ALLYLATION OF PHENOLS
Baruah, Jubaraj B.
, p. 8509 - 8512 (2007/10/02)
Phenols can be allylated at an ortho-position by use of a mixture of anhydrous copper(II) perchlorate and copper metal powder.
Clay catalyzed rearrangement of substituted allyl phenyl ethers: Synthesis of ortho-allyl phenols, chromans and coumarans
Dauben, William G.,Cogen, Jeffrey M.,Behar, Victor
, p. 3241 - 3244 (2007/10/02)
Montmorillonite clays catalyze the rearrangement of substituted allyl phenyl ethers to provide ortho-allyl phenols, chromans and coumarans under mild conditions.
The Behaviour of 2H-1-Benzopyrans Toward Trialkylaluminium Reagents
Alberola, Angel,Ortega, Alfonso Gonzalez,Pedrosa, Rafael,Bragado, Jose L. Perez,Amo, Justo F. Rodriguez
, p. 1209 - 1212 (2007/10/02)
2H-1-Benzopyrans react with trialkylaluminium compounds by alkyl- and hydrogen-transfer to C-2 and C-4 to give the o-allylphenols (2), (3), and the (E)-o-propenylphenols (4) and (5).The site of attack and the ratio of alkyl- to hydrogen-transfer depend on the alkylaluminium used and on the size of the substituent at C-2 of the pyran.A mechanism involving reaction of the alkylaluminium with the quinone methanide (6), which is in equilibrium with the pyran (1), is in accord with all experimental results.
