A new and efficient methodology for olefin epoxidation catalyzed by supported cobalt nanoparticles

• Lucía Rossi-Fernández,
• Viviana Dorn and
• Gabriel Radivoy

Beilstein J. Org. Chem. 2021, 17, 519–526, doi:10.3762/bjoc.17.46

• been reported, efficient and selective epoxidation of olefins remains a challenge. Due to safety and environmental issues, traditional methods involving the use of stoichiometric amounts of harmful oxidants (for example, peroxosulfates [13] or organic peracids [14]) have been replaced by the use of

Unexpected one-pot formation of the 1H-6a,8a-epiminotricyclopenta[a,c,e][8]annulene system from cyclopentanone, ammonia and dimethyl fumarate. Synthesis of highly strained polycyclic nitroxide and EPR study

• Sergey A. Dobrynin,
• Igor A. Kirilyuk,
• Yuri V. Gatilov,
• Andrey A. Kuzhelev,
• Olesya A. Krumkacheva,
• Matvey V. Fedin,
• Michael K. Bowman and
• Elena G. Bagryanskaya

Beilstein J. Org. Chem. 2019, 15, 2664–2670, doi:10.3762/bjoc.15.259

• assignment was based on the single-crystal X-ray analysis (Figure 4) and a possible mechanism for this hydroxylation is shown in Scheme 4. Oxidation of amines with peracids is known to proceed through oxoammonium cation formation [12]. The close proximity of this reactive group to the allyl hydrogen results

Synthesis of 1-azaspiro[4.4]nonan-1-oxyls via intramolecular 1,3-dipolar cycloaddition

• Yulia V. Khoroshunova,
• Denis A. Morozov,
• Andrey I. Taratayko,
• Polina D. Gladkikh,
• Yuri I. Glazachev and
• Igor A. Kirilyuk

Beilstein J. Org. Chem. 2019, 15, 2036–2042, doi:10.3762/bjoc.15.200

• C11H18NO2, which matches element analysis data. These results allowed us to assign the structure 15 to this nitroxide. Indeed, oxidation of amines with peracids is known to proceed via oxoammonium cation formation [17][18], and the latter can oxidize alcohols to carbonyl compounds [19]. The close proximity

Synthesis of ergostane-type brassinosteroids with modifications in ring A

• Vladimir N. Zhabinskii,
• Darya A. Osiyuk,
• Yuri V. Ermolovich,
• Natalia M. Chaschina,
• Tatsiana S. Dalidovich,
• Miroslav Strnad and
• Vladimir A. Khripach

Beilstein J. Org. Chem. 2017, 13, 2326–2331, doi:10.3762/bjoc.13.229

• isomeric 2,3-epoxides 22 and 24 with a 7-membered B-ring lactone was accomplished starting from the olefin 21 (Scheme 4). The reaction of peracids with Δ2-steroids possessing a six-membered B ring is known to proceed from the less hindered side of the molecule and results in the formation of 2α,3α-epoxides

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• Smith rearrangements are of interest in allyl hydroperoxide transformations. 1.1 Baeyer–Villiger oxidation The BV reaction is the oxidation of ketones or aldehydes A under the action of hydrogen peroxide, hydroperoxides, Caro’s acid (H2SO5), or organic peracids to yield esters, lactones, or carboxylic

• of peracids to oxidize cyclic and acyclic ketones and aldehydes to the corresponding lactones, esters, and carboxylic acids decreases in the series peroxotrifluoroacetic acid > monopermaleic acid > mono-o-perphthalic acid > 3,5-dinitroperbenzoic acid > p-nitroperbenzoic acid > MCPBA ≈ performic acid

• generated peracids from carbodiimide, hydrogen peroxide, and carboxylic acids as catalysts ketones 37 are rearranged to lactones 38 (Scheme 11) [229]. 3,4-Dimethoxybenzoic acid (40) was prepared with 78% yield by a Baeyer–Villiger reaction of substrate 39 with 30% H2O2, HCOOH and 1,2-dichloroethane at 50 °C

Photoinduced 1,2,3,4-tetrahydropyridine ring conversions

• Baiba Turovska,
• Henning Lund,
• Viesturs Lūsis,
• Anna Lielpētere,
• Edvards Liepiņš,
• Sergejs Beljakovs,
• Inguna Goba and
• Jānis Stradiņš

Beilstein J. Org. Chem. 2015, 11, 2166–2170, doi:10.3762/bjoc.11.234

• of 1 can be described as shown in Scheme 1. In an air saturated CHCl3 solution, the concentration of dioxygen is about 2 mmol/L [17][18] and if it becomes comparable with the concentration of 1, the reaction takes a different course (Scheme 2). It has been suggested that peracids attack the carbon

Cross-dehydrogenative coupling for the intermolecular C–O bond formation

• Igor B. Krylov,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2015, 11, 92–146, doi:10.3762/bjoc.11.13

• , such as copper and manganese salts, were less often employed for this purpose. 3.1 Oxidative systems based on iodine compounds Iodine(III) organic compounds, including those generated in situ from aryl iodides and peracids (for example, m-chloroperbenzoic acid (MCPBA) and peracetic acid) are most

Nonanebis(peroxoic acid): a stable peracid for oxidative bromination of aminoanthracene-9,10-dione

• Vilas Venunath Patil and
• Ganapati Subray Shankarling

Beilstein J. Org. Chem. 2014, 10, 921–928, doi:10.3762/bjoc.10.90

• -9,10-dione, which is highly deactivated towards the electrophilic substitution is investigated. The peracid, nonanebis(peroxoic acid), possesses advantages such as better stability at room temperature, it is easy to prepare and non-shock sensitiv as compared to the conventional peracids. The present

• an oxidant in the reaction, which re-oxidizes the HBr and utilizes up to 90–95% [25][26] of bromine. Various oxidants are used for this purpose [27][28][29][30]. Compared to these commonly used oxidants the use of peracids is likely to be limited due to their instability and the resulting storage

• issues. These peracids are either have to be prepared in situ or they require cold storage conditions [31]. Finding that there is a need to develop a stable peracid, we synthesized a stable, solid, aliphatic long chain peracid, nonanebis(peroxoic acid). This peracid is easy to synthesize and possesses

Metal-free aerobic oxidations mediated by N-hydroxyphthalimide. A concise review

• Lucio Melone and
• Carlo Punta

Beilstein J. Org. Chem. 2013, 9, 1296–1310, doi:10.3762/bjoc.9.146

• PINO radical following a molecule-induced homolysis mechanism [52]. Molecule-induced initiation is a process driven by a thermodynamic effect and consists of a bimolecular reaction according to which an OH radical, generated from hydroperoxides or peracids, undergoes hydrogen abstraction from a

• suitable molecule bearing relatively weak X–H bonds. The result is the formation of two radical species and a molecule of water (Scheme 18) [53][54][55]. We assumed that an analogous homolysis induced by peracids could occur for this NHPI, leading to the formation of PINO radical under mild and metal-free

• aerobic oxidation of aldehydes could be performed for the in situ generation of the corresponding peracids in the presence of NHPI, promoting co-oxidative processes catalyzed by PINO. In an early protocol, we reported the NHPI-catalyzed selective aerobic epoxidation of α-olefins and cyclic olefins in the

The development and evaluation of a continuous flow process for the lipase- mediated oxidation of alkenes

• Charlotte Wiles,
• Marcus J. Hammond and
• Paul Watts

Beilstein J. Org. Chem. 2009, 5, No. 27, doi:10.3762/bjoc.5.27

• ; hydrogen peroxide; lipase; micro reactor; Novozym® 435; peracids; Introduction In addition to their synthetic value as intermediates in the preparation of diols, alcohols, hydroxyesters and alkenes, epoxides are a key raw material in many industrial processes, finding application in adhesives, polymers

• ] or peracids [6] such as m-chloroperbenzoic acid (m-CPBA) [7][8]. The hazardous nature of these techniques and the potential to hydrolyse the epoxide [9] however precludes their use on a large scale. Many of the epoxides produced industrially are synthesised using the chlorohydrin method, or via in

• situ generated peracids derived from formic acid or acetic acid (1)/hydrogen peroxide (2). As H2O2 (2) is itself not sufficiently electrophilic to epoxidise a non-conjugated double bond directly, its use in the formation of a peracid has afforded a route to the epoxidation of alkenes in the presence of