59115-82-1Relevant academic research and scientific papers
Benzyl C–O and C–N Bond Construction via C–C Bond Dissociation of Oxime Ester under Visible Light Irradiation
Fan, Xiuwei,Lei, Tao,Liu, Zan,Yang, Xiu-Long,Cheng, Yuan-Yuan,Liang, Ge,Chen, Bin,Tung, Chen-Ho,Wu, Li-Zhu
, p. 1551 - 1558 (2019/09/09)
A photoredox benzyl activation was developed via formidable C(sp3)–C(sp3) bond dissociation of 1-aryl acetone oxime esters, which were easily prepared from benzyl ketones. Further coupling with O- and N- nucleophiles successfully forged important benzyl ether and amines derivatives in one pot. In this process, different substitutions on oxime esters were found compatible and various primary and secondary alcohols and amines, as well as amides showed good performance as nucleophiles. Mechanistic studies by control experiments, electrochemical measurements and in-situ NMR spectra proposed a N–O bond interruption/C–C bond fragmentation/oxidation sequence to provide the key cation intermediate for the next electrophilic SN process. The features of mild condition, short reaction time and broad substrate scope made this new strategy much promising in the transformation of benzyl compounds, which might be valuable in last-stage functionalizations.
Two efficient pathways for the synthesis of aryl ketones catalyzed by phosphorus-free palladium catalysts
Wirwis,Feder-Kubis,Trzeciak
, p. 61 - 72 (2018/01/05)
Allylic alcohols, 1-buten-3-ol, 1-penten-3-ol and 1-octen-3-ol, reacted with aryl iodides (iodotoluene, 4-iodotoluene, 4-iodophenol and 4-iodanisole) under Heck reaction conditions to form corresponding saturated aryl ketones in one step. The same products were obtained in a two-step tandem reaction consisted of the Heck coupling of allylic alcohols with aryl iodides, followed by hydrogenation. Reactions were catalyzed by phosphorus-free palladium precursors modified with the menthol-substituted imidazolium chlorides. Formation of crystalline palladium nanoparticles, of the diameter up to 65 nm, in the reaction mixture was evidenced by TEM.
Regioselective 1,2-Diol Rearrangement by Controlling the Loading of BF3·Et2O and Its Application to the Synthesis of Related Nor-Sesquiterene- and Sesquiterene-Type Marine Natural Products
Wang, Jun-Li,Li, Hui-Jing,Wang, Hong-Shuang,Wu, Yan-Chao
supporting information, p. 3811 - 3814 (2017/07/26)
The regiocontrolled rearrangement of 1,2-diols has been achieved by controlling the loading of BF3·Et2O. Its applicability is showcased by the divergent synthesis of austrodoral, austrodoric acid, and 8-epi-11-nordriman-9-one, as well as a formal synthesis of siphonodictyal B and liphagal. A new light is shed on piancol-type rearrangements that will be useful in diversity-oriented synthesis of related natural products.
Control of the Chemoselectivity of Metal N-Aryl Nitrene Reactivity: C-H Bond Amination versus Electrocyclization
Kong, Chen,Jana, Navendu,Jones, Crystalann,Driver, Tom G.
supporting information, p. 13271 - 13280 (2016/10/22)
A mechanism study to identify the elements that control the chemoselectivity of metal-catalyzed N-atom transfer reactions of styryl azides is presented. Our studies show that the proclivity of the metal N-aryl nitrene to participate in sp3-C-H bond amination or electrocyclization reactions can be controlled by either the substrate or the catalyst. Electrocyclization is favored for mono-β-substituted and sterically noncongested styryl azides, whereas sp3-C-H bond amination through an H-atom abstraction-radical recombination mechanism is preferred when a tertiary allylic reaction center is present. Even when a weakened allylic C-H bond is present, our data suggest that the indole is still formed through an electrocyclization instead of a common allyl radical intermediate. The site selectivity of metal N-aryl nitrenes was found to be controlled by the choice of catalyst: Ir(I)-alkene complexes trigger electrocyclization processes while Fe(III) porphyrin complexes catalyze sp3-C-H bond amination in substrates where Rh2(II) carboxylate catalysts provide both products.
Palladium-catalyzed mono-α-arylation of carbonyl-containing compounds with aryl halides using dalphos ligands
Crawford, Sarah M.,Alsabeh, Pamela G.,Stradiotto, Mark
, p. 6042 - 6050,9 (2020/09/02)
We report the extension and optimization of the [Pd(cinnamyl)Cl] 2/DalPhos catalyst system, previously found effective for the mono-α-arylation of acetone, to the mono-α-arylation of a variety of carbonyl-containing compounds with aryl halides and heteroaryl halides. Aryl methyl ketones, heteroaryl methyl ketones, propiophenones, malonates, and methoxyacetone can be α-arylated under relatively mild conditions and in good yields. We also report the limitations of the ligand/catalyst system towards other classes of carbonyl-containing compounds. We report the application of the [Pd(cinnamyl)Cl]2/DalPhos catalyst system, previously found effective for the mono-α-arylation of acetone, to the mono-α-arylation of a variety of carbonyl-containing compounds with aryl halides and heteroaryl halides.
Origin of regioselectivity in the reactions of nitronate and enolate ambident anions
Sakata, Tomomi,Seki, Natsuko,Yomogida, Kozue,Yamagishi, Hiroko,Otsuki, Akino,Inoh, Chie,Yamataka, Hiroshi
, p. 10738 - 10744 (2013/02/25)
The reactions of nitronates of ring-substituted phenylnitromethanes and enolates of ring-substituted 1-phenyl-2-propanones with MeOBs gave exclusively the O-methylated and C-methylated products, respectively. DFT calculations suggested that two factors, n
GaCl3-catalyzed skeletal rearrangement of α,α, α-trisubstituted aldehydes
Oshita, Masayuki,Okazaki, Takao,Ohe, Kouichi,Chatani, Naoto
, p. 331 - 334 (2007/10/03)
(Chemical Equation Presented) GaCl3 is found to be a superior catalyst for the skeletal rearrangement of α,α,α- trisubstituted aldehydes to ketones. The rearrangement can proceed smoothly in the presence of a catalytic amount of GaCl3, and even substrates having no heteroatoms α to the carbonyl group or without steric strains can be used. Double activation of a carbonyl group by two molecules of GaCl 3 was supported on the basis of experimental data and a DFT study.
The Allopolarization Principle and its Applications, IV. Substituent Effects in the Methylation of Enolate Anions
Gompper, Rudolf,Vogt, Hans-Hubert
, p. 2866 - 2883 (2007/10/02)
The ratio of O- and C-methylated products in the reaction of the sodium salts of acetophenones 1, propiophenones 3, phenylacetones 5, β-dicarbonyl compounds 12, α-cyanocarbonyl compounds 13, acetaldehyde, propionaldehyde, and diethylketone with dimethyl sulfate, methyl iodide, and trimethyl phosphate in HMPTA has been determined with regard to the effect of substituents.In some cases the influence of solvents, concentration and temperature has also been studied.
