466-37-5Relevant academic research and scientific papers
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.
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.
Tandem Acid/Pd-Catalyzed Reductive Rearrangement of Glycol Derivatives
Ciszek, Benjamin,Fleischer, Ivana,Kathe, Prasad,Schmidt, Tanno A.
supporting information, p. 3641 - 3646 (2020/03/25)
Herein, we describe the acid/Pd-tandem-catalyzed transformation of glycol derivatives into terminal formic esters. Mechanistic investigations show that the substrate undergoes rearrangement to an aldehyde under [1,2] hydrogen migration and cleavage of an oxygen-based leaving group. The leaving group is trapped as its formic ester, and the aldehyde is reduced and subsequently esterified to a formate. Whereas the rearrangement to the aldehyde is catalyzed by sulfonic acids, the reduction step requires a unique catalyst system comprising a PdII or Pd0 precursor in loadings as low as 0.75 mol % and α,α′-bis(di-tert-butylphosphino)-o-xylene as ligand. The reduction step makes use of formic acid as an easy-to-handle transfer reductant. The substrate scope of the transformation encompasses both aromatic and aliphatic substrates and a variety of leaving groups.
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.
Pinacol Rearrangement and Direct Nucleophilic Substitution of Allylic Alcohols Promoted by Graphene Oxide and Graphene Oxide CO2H
Gómez-Martínez, Melania,Baeza, Alejandro,Alonso, Diego A.
, p. 1032 - 1039 (2017/03/27)
Graphene oxide (GO) and carboxylic acid functionalized GO (GO–CO2H) have been found to efficiently promote the heterogeneous and environmentally friendly pinacol rearrangement of 1,2-diols and the direct nucleophilic substitution of allylic alcohols. In general, high yields and regioselectivities are obtained in both reactions using 20 wt % of catalyst loading and mild reaction conditions.
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.
New insights into the bifunctionality of vanadium phosphorous oxides: A chemical switch between oxidative scission and pinacol rearrangement of vicinal diols
Upadhyaya, Dharita J.,Samant, Shriniwas D.
, p. 60 - 65 (2013/06/27)
New insights into the bifunctionality of vanadium phosphorus oxides (VPOs) were obtained. This study reports the precise tuning of experimental conditions, which act as the switch to direct the course of reaction selectively to obtain either CC oxidative scission or an acid-catalysed rearrangement of vicinal diols. The catalyst was synthesized and characterized to identify the active vanadyl pyrophosphate phase. The present method was extended further to develop a new environmentally benign and green catalytic protocol for oxidative cleavage of a variety of vicinal diols with 100% selectivity towards the corresponding aldehydes or ketones using H2O2 as the oxidizing agent.
o-benzenedisulfonimide as reusable bronsted acid catalyst for acid-catalyzed organic reactions
Barbero, Margherita,Cadamuro, Silvano,Dughera, Stefano,Venturello, Paolo
, p. 1379 - 1388 (2008/12/21)
Acid-catalyzed organic reactions, such as etherification, esterification, acetal synthesis, cleavage, and interconversion, and pinacol rearrangement were carried out in the presence of catalytic amounts of o-benzenedisulfonimide as Bronsted acid catalyst; the conditions were mild and selective. The catalyst was easily recovered and purified, ready to be used in further reactions, with economic and ecological advantages. Georg Thieme Verlag Stuttgart.
SiCl4-Zn induced reductive coupling of carbonyl compounds: novel and efficient routes for one-pot syntheses of 1,2,3-triaryl-2-propen-1-ones and pinacolones at room temperature
Salama, Tarek A.,Elmorsy, Saad S.,Khalil, Abdel-Galel M.
, p. 4395 - 4398 (2008/02/03)
An unprecedented one-pot reductive trimerization of aromatic aldehydes to 1,2,3-triaryl-2-propen-1-ones as well as tandem reductive coupling-rearrangements of aryl ketones to pinacolone analogues was efficiently achieved using tetrachlorosilane-zinc at room temperature.
