1195-44-4Relevant articles and documents
O-alkylation of N-phenylhydroxylamine in dimethyl sulfoxide with methylarenesulfonates
Fountain,White, Robert D.,Patel, Kamlesh D.,New, Dallas G.,Xu, YuBo,Cassely, Aaron J.
, p. 9434 - 9436 (1996)
The methylation of N-phenylhydroxylamine (NPHA) with methylarenesulfonates in DMSO gives alkylation of the O atom in contrast to methylation in methanol where N alkylation occurs. The Hammett p values indicate that alkylations with N-methylanilines and NPHAs both involve the N atom. The NPHAs show "nominal α-effects" but involve comparison of N atoms with O atoms. The reactivity of the principle component, the zwitterion I, is examined with leaving group studies and comparison with benzyl alkoxide reactivity.
Cobalt-Catalysed Reductive Etherification Using Phosphine Oxide Promoters under Hydroformylation Conditions
Beller, Matthias,Delolo, Fábio G.,Fessler, Johannes,Gusevskaya, Elena V.,Junge, Kathrin,Neumann, Helfried,dos Santos, Eduardo N.
supporting information, (2022/02/19)
A phosphine-oxide-promoted, cobalt-catalysed reductive etherification using syngas as a reductant is reported. This novel methodology was successfully used to prepare a broad range of unsymmetrical ethers from various aldehydes and alcohols containing diverse functional groups, and was scaled-up to multigram scale under comparably mild conditions. Mechanistic experiments support an acetalization–hydrogenation sequence.
Co2(CO)8-catalyzed reactions of acetals or lactones with hydrosilanes and carbon monoxide. A new access to the preparation of 1,2-diol derivatives through siloxymethylation
Chatani, Naoto,Fujii, Satoru,Kido, Yoichi,Nakayama, Yasuhide,Kajikawa, Yasuteru,Tokuhisa, Hideo,Fukumoto, Yoshiya,Murai, Shinji
, p. 81 - 90 (2021/02/05)
The Co2(CO)8-catalyzed reaction of acetals with hydrosilanes and CO under mild reaction conditions (an ambient temperature under an ambient CO pressure), leading to the production of vicinal diols is reported. A siloxymethyl group can be introduced via the cleavage of one of two alkoxy groups in the acetal. The effects of the types of hydrosilanes, acetals, solvents, and reaction temperatures on the yield of siloxymethylation products were examined in detail. The reactivity for hydrosilanes is as follows; HSiMe3 > HSiEtMe2 > HSiEt2Me > HSiEt3. Hemiacetal esters are more reactive than dimethyl acetals. The polarity of the solvent used also has a significant effect on both the course of the reaction as well as the reaction rate. The site-selective siloxymethylation can be achieved in the case of cyclic acetals such as tetrahydrofuran (THF) and tetrahydropyrane (THP) derivatives, depending on the nature of the oxygen substituent attached adjacent to the oxygen atom in the ring. When 2-alkoxy THF or THP derivatives are used as substrates, the siloxymethylation takes place with cleavage of the ring C-O bond. In contrast, the reaction of 2-acetoxy THF or THP derivatives results in siloxymethylation with the cleavage of C-OAc bond. The ring-opening siloxymethylation of lactones was also examined.
Visible light mediated oxidation of benzylic sp3 C-H bonds using catalytic 1,4-hydroquinone, or its biorenewable glucoside, arbutin, as a pre-oxidant
Finney, Laura C.,Mitchell, Lorna J.,Moody, Christopher J.
supporting information, p. 2242 - 2249 (2018/05/28)
Benzylic ethers undergo a visible light induced C-H activation and oxygen insertion to give the corresponding benzoate esters in moderate to good yields. The conditions employ substoichiometric amounts of 1,4-hydroquinone with copper(ii) chloride dihydrate as an electron-transfer mediator, oxygen as the terminal oxidant and dimethyl carbonate as solvent under visible light irradiation. The naturally occurring glucoside, arbutin, which is commercially available or can be accessed via extraction of the leaves of bearberry (Arctostaphylos uva-ursi) or elephant ears (Bergenia crassifolia) can be used as a biorenewable source of 1,4-hydroquinone. The methodology exploits the increase in oxidizing ability of quinones upon irradiation with visible light, and offers a sustainable alternative for the late stage oxidative functionalization of benzylic C-H bonds. It is applicable to a range of cyclic benzylic ethers such as isochromans and phthalans, and simple benzyl alkyl ethers. It can also be applied in the oxidation of benzylic amines into amides, and of diarylmethanes into the corresponding ketones. Mechanistic studies suggest that the reaction proceeds by H-abstraction by the photo-excited triplet benzoquinone to give a benzylic radical that subsequently reacts with molecular oxygen.
Methoxymethylation and benzyloxymethylation of aryl bromides
Panda, Biswajit
, p. 981 - 985 (2020/06/26)
The methoxymethylation and benzyloxymethylation of aryl bromides methodology was reported here. The transition metal free, high yielding one pot procedure will be useful for synthetic community.
Auto-Tandem Catalysis with Frustrated Lewis Pairs for Reductive Etherification of Aldehydes and Ketones
Bakos, Mária,Gy?m?re, ádám,Domján, Attila,Soós, Tibor
supporting information, p. 5217 - 5221 (2017/04/27)
Herein we report that a single frustrated Lewis pair (FLP) catalyst can promote the reductive etherification of aldehydes and ketones. The reaction does not require an exogenous acid catalyst, but the combined action of FLP on H2, R-OH or H2O generates the required Br?nsted acid in a reversible, “turn on” manner. The method is not only a complementary metal-free reductive etherification, but also a niche procedure for ethers that would be either synthetically inconvenient or even intractable to access by alternative synthetic protocols.
Selective O-methylation of phenols and benzyl alcohols in simple pyridinium based ionic liquids
Das, Pranab Jyoti,Das, Jupitara
, p. 94 - 98 (2015/06/08)
Synthesis of pyridinium based ionic liquids were reported and applied as catalyst for the selective O-methylation of phenols and benzyl alcohols. The reactions were carried out by using dimethylcarbonate (DMC) as the methylating agent. High selectivity, high yield and recyclability of the ionic liquids are important features of the reactions.
Eco-efficient preparation of a N-doped graphene equivalent and its application to metal free selective oxidation reaction
Singh, Ajay K.,Basavaraju,Sharma, Siddharth,Jang, Seungwook,Park, Chan Pil,Kim, Dong-Pyo
supporting information, p. 3024 - 3030 (2014/06/10)
Here, we demonstrate that graphene oxide (GO) can be converted to N-doped reduced GO (rGO) that could become a substitute for N-doped graphene. Simultaneous doping and reduction can be accomplished for this purpose by simply mixing GO with hydrazine and then continuously sonicating the solution at 65 °C. A high level of reduction is realized, as evidenced by a carbon to oxygen ratio of 20.7 that compares with the highest value of 15.3 ever reported in solution (water + hydrazine) methods. Nitrogen doping is possible up to 6.3 wt% and the extent of doping can be increased with increasing sonication time. Notably, the simple tuning process of N-doping in GO greatly enhanced the efficiency of the carbocatalyst for various kinds of metal free oxidation reactions and hence is proposed as a suitable candidate for future industrial applications. This journal is the Partner Organisations 2014.
Reductive etherification of aldehydes photocatalyzed by dicarbonyl pentamethylcyclopentadienyl iron complexes
Argouarch, Gilles,Grelaud, Guillaume,Roisnel, Thierry,Humphrey, Mark G.,Paul, Frédéric
supporting information, p. 5015 - 5018 (2012/11/07)
The reductive etherification of aldehydes can be performed by the reaction with dialkylmethylsilanes in the presence of new iron(II) piano-stool catalysts of general formula Cp*Fe(CO)2Ar (Cp * = η5-C5Me5; Ar = Ph, 4-C6H4OCH3, 4-C6H4CH 3, Fc). This transformation is promoted by UV light and affords a simple route for the preparation of unsymmetrical alkyl ethers.
New method for the synthesis of benzyl alkyl ethers mediated by FeSO 4
Joshi, Girdhar,Adimurthy, Subbarayappa
experimental part, p. 720 - 728 (2011/03/22)
The synthesis of benzyl alkyl ethers from benzyl bromides and alcohols using FeSO4 as a recoverable and reusable mediator has been described without use of base and cosolvent under mild conditions.
