466-37-5Relevant articles and documents
ATOMIC FORCE MICROSCOPY AND SOLID-STATE REARRANGEMENT OF BENZOPINACOL
Kaupp, Gerd,Haak, Michael,Toda, Fumio
, p. 545 - 551 (1995)
The solid-solid chemical reaction of benzopinacol (1) with p-toluenesulphonic acid monohydrate (2) to give a quantitatively proton-catalysed pinacol rearrangement with formation of triphenylacetophenone (3) in the absence of a solvent was studied preparatively and mechanistically using atomic force microscopy (AFM) measurements and known crystal structure data.The reaction rate is dramatically enhanced if the water of reaction is continuously removed.AFM reveals that no reaction occurs on (001) of 1 whereas (100) exhibits distance dependent craters and volcano-like mounds over areas extending to 1.5 mm from the contact edge of the crystal with 1 undergoing phase rebuilding while reacting.A mechanism resembling the formation of membrane potentials is seen for the first time in crystals.This it appears that catalytic protons migrate without their counterions from one molecular compartment to the next by proton consumption at its inside and proton liberation at its outside, which is the inside of the next compartment.The uppermost molecular layer determines reactivity or non-reactivity.On (001) of 1 the hydroxyl groups occur with their hydrogens up.Hence no AFM features are found and crystals of 2 do not become adhered to 1.However, on (100) the hydroxyl hydrogens point down (free electron pair up).Protonation is possible, chemical reaction is indicated by the formation of the AFM features and crystals of 2 adhere firmly to the surface of 1 after reaction.
Solvent-washable polymer templated synthesis of mesoporous materials and solid-acid nanocatalysts in one-pot
Mishler Ii, Richard E.,Biradar, Ankush V.,Duncan, Cole T.,Schiff, Eric A.,Asefa, Tewodros
, p. 6201 - 6203 (2009)
We report a new and simple one-pot synthetic method to produce mesoporous silica and nanoporous solid acid catalyst capable of catalyzing pinacole-pinacolone rearrangement and esterification reactions, by preparing a solvent washable phosphonated triblock copolymer template and self-assembling it in the presence of alkoxysilane.
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Gebhart,Adams
, p. 3925,3926 (1954)
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Method for preparing substituted carbonyl compound by catalyzing pinacol rearrangement reaction through molecular sieve
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Paragraph 0021-0026, (2020/09/12)
The invention discloses a method for preparing a substituted carbonyl compound by catalyzing pinacol rearrangement reaction through a molecular sieve. The method is characterized in that substituted pinacol as a substrate and toluene as solvent are subjected to a rearrangement reaction for 2-5h under the catalysis of an MCM-41, SBA-15, USY, Beta ZSM-5 or other aluminum-containing H-type acidic molecular sieve, the reaction temperature is 80-110 DEG C, the mass ratio of the substituted pinacol to the toluene to the catalyst is 100: 100: (10-50), the catalyst is filtered out after the reaction is finished, and purifying is performed to obtain a product, namely, the substituted carbonyl compound. Compared with the prior art, the method provided by the invention has the advantages of wide substrate application range, cheap catalyst, easy preparation, stability, no pollution to the environment, recyclability, realization of gram-scale preparation, and high reaction yield.
Lewis Acid Assisted Electrophilic Fluorine-Catalyzed Pinacol Rearrangement of Hydrobenzoin Substrates: One-Pot Synthesis of (±)-Latifine and (±)-Cherylline
Shi, Hui,Du, Chuan,Zhang, Xinhang,Xie, Fukai,Wang, Xiaoyu,Cui, Shanshan,Peng, Xiaoshi,Cheng, Maosheng,Lin, Bin,Liu, Yongxiang
, p. 1312 - 1319 (2018/02/09)
A microwave-irradiated solvent-free pinacol rearrangement of hydrobenzoin substrates catalyzed by a combination of N-fluorobenzenesulfonimide and FeCl3·6H2O was developed. Its selectivity was first investigated by density functional theory (DFT) calculations. Then the functional group tolerance was examined by synthesizing a series of substrates designed based on the insight provided by the DFT calculations. The application of the methodology was demonstrated by the efficient one-pot synthesis of (±)-latifine and (±)-cherylline, both are 4-aryltetrahydroisoquinoline alkaloids isolated from Amaryllidacecae plants.
Tetraarylethylenes from Diarylmethanones and Hexachlorodisilane: The “Sila-McMurry” Reaction
Moxter, Maximilian,Tillmann, Jan,Füser, Matthias,Bolte, Michael,Lerner, Hans-Wolfram,Wagner, Matthias
supporting information, p. 16028 - 16031 (2016/10/26)
Hexachlorodisilane reacts with diarylmethanones (aryl=C6H5, 4-MeC6H4, 4-tBuC6H4, 4-ClC6H4, 4-BrC6H4) to furnish the corresponding tetraarylethylenes in good yields. The reductive conversion requires temperatures of about 160 °C and reaction times of 60–72 h. In the initial step, the Lewis-basic carbonyl groups likely generate low-valent [SiCl2] as an analogue of [TiCl2] in the classical McMurry reaction. The coupling sequence further proceeds via benzopinacolones, which have been isolated as key intermediates.
