13990-72-2Relevant academic research and scientific papers
Subsupercritical Water Generated by Inductive Heating Inside Flow Reactors Facilitates the Claisen Rearrangement
Oltmanns, Mona,Kirschning, Andreas
, p. 1942 - 1946 (2020)
Claisen rearrangement of electron-deficient O-allylated phenols, including fluorine-modified phenols, is facilitated in aqueous media at high temperatures and pressures under flow conditions, as opposed to organic solvents. The O-allylation of phenols can be coupled with the Claisen rearrangement in an integrated flow system.
Palladium-catalyzed anti-Markovnikov oxidative acetalization of activated olefins with iron(iii) sulphate as the reoxidant
Fernandes, Rodney A.,Kumar, Praveen,Yadav, Sandhya S.
, p. 427 - 443 (2022/01/20)
This paper discloses the efficient palladium-catalyzed anti-Markovnikov oxidative acetalization of activated terminal olefins with iron(iii) sulfate as the reoxidant. This methodology requires mild reaction conditions and shows high regioselectivity toward anti-Markovnikov products and compatibility with a wide range of functional groups. Iron(iii) sulphate was the sole reoxidant used in this method. Various olefins like vinylarenes, aryl-allylethers, aryl or benzyl acrylates and homoallylic alcohols all reacted well providing anti-Markovnikov acetals, some of which represent orthogonally functionalized 1,3- and 1,4-dioxygenated compounds.
Metal-free Photochemical Atom Transfer Radical Addition (ATRA) of BrCCl3 to Alkenes
Nikitas, Nikolaos F.,Voutyritsa, Errika,Gkizis, Petros L.,Kokotos, Christoforos G.
supporting information, p. 96 - 101 (2021/01/04)
A simple, photochemical, and metal-free protocol for the atom transfer radical addition (ATRA) of bromotrichloromethane onto various alkenes is described. Among a range of organic molecules, phenylglyoxylic acid proved to be the most suitable photoinitiator to promote a sustainable process for the addition of bromotrichloromethane to olefins. This photochemical atom transfer radical protocol can be expanded into a wide substrate scope of aliphatic olefins bearing various functional groups, leading to the corresponding products in good to excellent yields.
Enantioselective synthesis of 1-aminoindene derivativesviaasymmetric Br?nsted acid catalysis
Ding, Du,Jiang, Hua-Jie,Wang, Tao,Wu, Xiang,Zhang, Ying,Zhao, Li-Ping
supporting information, p. 9680 - 9683 (2021/09/30)
We describe a catalytic asymmetric iminium ion cyclization reaction of simple 2-alkenylbenzaldimines using a BINOL-derived chiralN-triflyl phosphoramide. The corresponding 1-aminoindenes and tetracyclic 1-aminoindanes are formed in good yields and high enantioselectivities. Further, the chemical utility of the obtained enantiopure 1-aminoindene is demonstrated for the asymmetric synthesis of (S)-rasagiline.
Enantioselective Synthesis of 3-Fluorochromanes via Iodine(I)/Iodine(III) Catalysis
Daniliuc, Constantin G.,Gilmour, Ryan,Neufeld, Jessica,Sarie, Jér?me C.,Thiehoff, Christian
supporting information, p. 15069 - 15075 (2020/06/17)
The chromane nucleus is common to a plenum of bioactive small molecules where it is frequently oxidized at position 3. Motivated by the importance of this position in conferring efficacy, and the prominence of bioisosterism in drug discovery, an iodine(I)/iodine(III) catalysis strategy to access enantioenriched 3-fluorochromanes is disclosed (up to 7:93 e.r.). In situ generation of ArIF2 enables the direct fluorocyclization of allyl phenyl ethers to generate novel scaffolds that manifest the stereoelectronic gauche effect. Mechanistic interrogation using deuterated probes confirms a stereospecific process consistent with a type IIinv pathway.
Chemoselective Epoxidation of Allyloxybenzene by Hydrogen Peroxide Over MFI-Type Titanosilicate
Fujitani, Tadahiro,Hong, Dachao,Ito, Satoru,Ji, Xinyi,Kon, Yoshihiro,Nakashima, Takuya,Osuga, Ryota,Sato, Kazuhiko,Yokoi, Toshiyuki
supporting information, (2020/04/15)
The chemoselective synthesis of 2-(phenoxymethyl)oxirane from allyloxybenzene is achieved with over 90 % yield in a sustainable reaction system using titanium-substituted silicalite-1 (TS-1) as a catalyst, hydrogen peroxide (H2O2) as an oxidant, and a mixture of MeOH/MeCN as a solvent at 40 °C. No acid-catalyzed side reactions prompted by the Lewis acidity of the Ti active site in TS-1 are observed. The TS-1 catalyst can also promote the formation of oxiranes from various p-substituted allyloxybenzenes in good yields. The reaction mechanism is investigated through the reaction with other allyloxy compounds. The results, which are supported by DFT calculations, indicate that an active species of Ti peroxides formed from the reaction of TS-1 with H2O2 selectively oxidizes the allyloxybenzene to 2-(phenoxymethyl)oxirane.
Enantioselective Construction of Si-Stereogenic Center via Rhodium-Catalyzed Intermolecular Hydrosilylation of Alkene
He, Tao,Liu, Li-Chuan,Ma, Wen-Peng,Li, Bin,Zhang, Qing-Wei,He, Wei
supporting information, p. 17011 - 17015 (2020/11/30)
Catalytic, enantioselective synthesis of stereogenic silicon compounds remains a challenge. Herein, we report a rhodium-catalyzed regio- and enantio-selective intermolecular hydrosilylation of alkene with prochiral dihydrosilane. This new method features a simple catalytic system, mild reaction conditions and a wide functional group tolerance.
Investigating the microwave-accelerated Claisen rearrangement of allyl aryl ethers: Scope of the catalysts, solvents, temperatures, and substrates
Hui, Zi,Jiang, Songwei,Qi, Xiang,Ye, Xiang-Yang,Xie, Tian
supporting information, (2020/05/18)
The microwave-accelerated Claisen rearrangement of allyl aryl ethers was investigated, in order to gain insight into the scope of the catalysts, solvents, temperatures, and substrates. Among the catalysts examined, phosphomolybdic acid (PMA) was found to greatly accelerate the reaction in NMP, at temperatures ranging from 220 to 300 °C. This method was found to be useful for preparing several intermediates previously reported in the literature using precious metal catalysts such as Au(I), Ag(I), and Pt(II). Additionally, substrates bearing bromo and nitro groups on the aryl portion required careful tailoring of the reaction conditions to avoid complex product profiles.
Photocatalytic Synthesis of γ-Lactones from Alkenes: High-Resolution Mass Spectrometry as a Tool to Study Photoredox Reactions
Triandafillidi, Ierasia,Kokotou, Maroula G.,Kokotos, Christoforos G.
supporting information, p. 36 - 39 (2018/01/17)
A mild photocatalytic manifold for the synthesis of γ-lactones has been developed. Utilizing Ru(bpy)3Cl2 as the photocatalyst, a cheap and reproducible synthetic protocol for γ-lactones has been introduced. Mechanistic studies revealed the successful monitoring of photocatalytic reactions and radical intermediates via high-resolution mass spectrometry.
A mild copper catalyzed method for the selective deprotection of aryl allyl ethers
Hemming, David S.,Talbot, Eric P.,Steel, Patrick G.
supporting information, p. 17 - 20 (2016/12/23)
Copper boryl reagents enable the selective cleavage of aryl allyl ethers to the corresponding phenols in good to moderate yields.
