64196-51-6Relevant academic research and scientific papers
Structure-Kinetics Correlations in Isostructural Crystals of α-(ortho-Tolyl)-acetophenones: Pinning Down Electronic Effects Using Laser-Flash Photolysis in the Solid State
Ayitou, Anoklase J.-L.,Flynn, Kristen,Jockusch, Steffen,Khan, Saeed I.,Garcia-Garibay, Miguel A.
supporting information, p. 2644 - 2648 (2016/03/12)
Aqueous suspensions of nanocrystals in the 200-500 nm size range of isostructural α-(ortho-tolyl)-acetophenone (1a) and α-(ortho-tolyl)-para-methylacetophenone (1b) displayed good absorption characteristics for flash photolysis experiments in a flow system, with transient spectra and decay kinetics with a quality that is similar to that recorded in solution. In contrast to solution measurements, reactions in the solid state were characterized by a rate limiting hydrogen transfer reaction from the triplet excited state and a very short-lived biradical intermediate, which does not accumulate. Notably, the rate for δ-hydrogen atom transfer of 1a (2.7 × 107 s-1) in the crystalline phase is 18-fold larger than that of 1b (1.5 × 106 s-1). With nearly identical molecular and crystal structures, this decrease in the rate of δ-hydrogen abstraction can be assigned unambiguously to an electronic effect by the para-methyl group in 1b, which increases the contribution of the 3π,π? configuration relative to the reactive 3n,π? configuration in the lowest triplet excited state. These results highlight the potential of relating single crystal X-ray structural data with absolute kinetics from laser flash photolysis.
Palladium-catalyzed α-arylation of arylketones at low catalyst loadings
Marelli, Enrico,Corpet, Martin,Davies, Sian R.,Nolan, Steven P.
supporting information, p. 17272 - 17276 (2015/02/05)
A general catalytic protocol for the α-arylation of aryl ketones has been developed. It involves the use of a preformed, bench-stable Pd-N-heterocyclic carbene pre-catalyst bearing IHept as an ancillary ligand, and allows the coupling of various functiona
A structureeactivity relationship study on the Wacker oxidation of stilbenes at ambient condition
Darabi, Hossein Reza,Mirzakhani, Mohsen,Aghapoor, Kioumars,Jadidi, Khosrow,Faraji, Laleh,Sakhaee, Nader
, p. 131 - 134 (2013/10/01)
To evaluate which structural elements of the stilbenes are responsible for their activity on the Wacker oxidation, a series of stilbenes with various functional moieties and substitution patterns were considered. In this regard, it is found that the oxidation rate of stilbenes strongly depends on their structures to give the corresponding carbonyl compounds. Consequently, the ortho position of alkene and methoxy groups plays a key role in the complexation with PdCl2. The oxidation process is clean with high selectivity of product and low percentage of byproducts.
N-heterocyclic carbene adducts of cyclopalladated ferrocenylpyridazine: Synthesis, structural characterization, and application in α-arylation of ketones with aryl chlorides
Xu, Chen,Li, Hong-Mei,Wang, Zhi-Qiang,Fu, Wei-Jun,Zhang, Yu-Qing,Ji, Bao-Ming
experimental part, p. 366 - 370 (2012/07/16)
A new ferrocene-based ligand 3-chloro-6-pyridazinylferrocene 1 and its N-heterocyclic carbene adducts 2-3 were synthesized and characterized by 1H NMR and IR spectroscopy, ESI-MS, and elemental analysis. Additionally, detailed structures of complexes 2-3 have been determined by single-crystal X-ray analysis. Complex 3 exhibited high catalytic activity for α-arylation of ketones with aryl chlorides. Typically, using 1mol% catalyst in the presence of 1.5 equivalents of tBuOK as base in dioxane at 100°C provided coupled products in good yields.
Carbene adduct of cyclopalladated ferrocenylimine catalyzed α-arylation of ketones with aryl chlorides or bromides
Zhang, Jinli,Yang, Xueqian,Cui, Xiuling,Wu, Yangjie
experimental part, p. 8800 - 8807 (2011/12/02)
Carbene adduct of cyclopalladated ferrocenylimine exhibited highly catalytic activity for the α-arylation of ketones with aryl halides. The corresponding products were obtained in moderate to excellent yields. Such protocol was applied to various ketones and a broad scope of aryl halides including aryl chlorides, bromides as well as unactivated and sterically hindered aryl halides.
Tandem pinacol coupling-rearrangement of aromatic aldehydes with hydrogen catalyzed by a combination of a platinum complex and a polyoxometalate
Branytska, Olena,Shimon, Linda J. W.,Neumann, Ronny
, p. 3957 - 3959 (2008/10/09)
Together with a strongly oxidizing polyoxometalate, H5PV 2Mo10O40, PtII(N-(2,6- diisopropylphenyl)pyrazin-2-ylmethanimine)Cl2 forms a combined catalyst that was active in the tandem pinacol coupling-rearrangement of aryl aldehydes to give mostly the corresponding diarylacetaldehyde in high yields using molecular hydrogen as the reducing agent. The Royal Society of Chemistry.
An efficient and mild protocol for the α-arylation of ketones mediated by an (imidazol-2-ylidene)palladium(acetate) system
Singh, Rohit,Nolan, Steven P.
, p. 5832 - 5840 (2007/10/03)
The activity of well-defined N-heterocyclic carbene (NHC)-palladium acetate complexes has been studied in the α-arylation of ketones. The enolate was generated in situ via use of slight excess of sodium tert-butoxide as base. The results showed a high act
Highly regioselective, sequential, and multiple palladium-catalyzed arylations of vinyl ethers carrying a coordinating auxiliary: An example of a heck triarylation process
Nilsson,Larhed,Hallberg
, p. 8217 - 8225 (2007/10/03)
This article describes the development of new auxiliary-accelerated Heck multiarylations by intramolecular presentation of the oxidative addition complex. The introduction of a specific, palladium-coordinating dimethylamino group allows for the desired chelation-accelerated and chelation-controlled tri- and diarylation reactions. We report (a) the first example of a Heck triarylation process, (b) highly selective palladium-catalyzed diarylations of alkyl vinyl ethers, and (c) a very rapid two-phase protocol for the microwave-assisted hydrolysis of amino-substituted, arylated vinyl ethers constituting an entry to diarylated ethanals and substituted desoxybenzoins. X-ray structures and product patterns support the suggested substrate-controlled Heck reaction pathway. The catalyst-directing alkyl dimethylamino functionality was rapidly (1-2 min) and efficiently released by microwave hydrolysis after Heck multiarylation reactions. The liberated aromatic carbonyl compounds were thereafter isolated and fully characterized.
REDUCTIVE COUPLING OF BENZOIC ACID HALIDES AND ESTERS USING LOW-VALENT TITANIUM
Dang, Y.,Geise, H. J.
, p. 375 - 380 (2007/10/02)
The reductive coupling of (substituted) benzoic acid chlorides and esters is achieved using low-valent titanium, generated from TiCl3 and LiAlH4.Both acid chlorides and esters seem to follow the same two reaction pathways: one path via tolanes to stilbenes, the other via benzils to complex mixtures of products arising from reduction and further coupling reactions.Although the exact product balance depends upon the reaction conditions the major product is (substituted) cis-stilbene.
