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

• for 24 h (Scheme 12) [230]. Oxone is a convenient reagent for the transformation of α,β-unsaturated ketones 43 of determined stereochemistry into vinyl acetates 44 via the Baeyer–Villiger reaction in dry DMF for 7–39 h (Scheme 13) [231]. Oxidation with H2O2–heteroorganic catalyst systems: The activity

Towards potential nanoparticle contrast agents: Synthesis of new functionalized PEG bisphosphonates

• Souad Kachbi-Khelfallah,
• Maelle Monteil,
• Margery Cortes-Clerget,
• Evelyne Migianu-Griffoni,
• Jean-Luc Pirat,
• Olivier Gager,
• Julia Deschamp and
• Marc Lecouvey

Beilstein J. Org. Chem. 2016, 12, 1366–1371, doi:10.3762/bjoc.12.130

• one step has been performed. Thus, tested oxidants were the Jones reagent [22], potassium permanganate [23], with catalytic o-iodoxybenzoic acid (IBX) in oxone [24] and catalytic 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) with bis(acetoxy)iodobenzene (BAIB) [25]. The first two conditions led to a

• PEG chain cleavage and the recovery of benzoic acid from alcohol 2. Besides, the mixture IBX/oxone gave the expected product inseparable of IBX byproducts. Only oxidation using TEMPO and BAIB furnished the pure corresponding carboxylic acid. Nevertheless, the low obtained yields encouraged us to test

Base metal-catalyzed benzylic oxidation of (aryl)(heteroaryl)methanes with molecular oxygen

• Hans Sterckx,
• Johan De Houwer,
• Carl Mensch,
• Wouter Herrebout,
• Kourosch Abbaspour Tehrani and
• Bert U. W. Maes

Beilstein J. Org. Chem. 2016, 12, 144–153, doi:10.3762/bjoc.12.16

• conditions. Oxidations of this kind using Oxone® [10][11], NaOCl [12] or especially peroxides [13][14][15][16][17][18][19] as the terminal oxidant are quite numerous. However, transformations using molecular oxygen are rare. Ishii showed that organocatalysts such as N-hydroxyphthalimide (NHPI) in combination

Friedel–Crafts-type reaction of pyrene with diethyl 1-(isothiocyanato)alkylphosphonates. Efficient synthesis of highly fluorescent diethyl 1-(pyrene-1-carboxamido)alkylphosphonates and 1-(pyrene-1-carboxamido)methylphosphonic acid

• Anna Wrona-Piotrowicz,
• Janusz Zakrzewski,
• Anna Gajda,
• Tadeusz Gajda,
• Anna Makal,
• Arnaud Brosseau and
• Rémi Métivier

Beilstein J. Org. Chem. 2015, 11, 2451–2458, doi:10.3762/bjoc.11.266

• Oxone®. 1-(Pyrene-1-carboxamido)methylphosphonic acid was obtained in a 87% yield by treating the corresponding diethyl phosphonate with Me3Si-Br in methanol. All of the synthesized amidophosphonates were emissive in solution and in the solid state. The presence of a phosphonato group brought about an

• desulfurization of thioamides to amides via reaction with Oxone®. Now we want to apply this approach to the synthesis of N-thioacyl- and acyl derivatives of 1-aminoalkylphosphonates from arenes and 1-(isothiocyanato)alkylphosphonates. 1-Aminoalkylphosphonates and their derivatives are compounds of biological

• reaction conditions. The structures of 2a–d were confirmed by spectroscopic and elemental analysis data and (for 3a) by a single-crystal X-ray diffraction study (vide infra). Thioamidophoshonates 2a–d readily reacted with Oxone® in acetonitrile–water at room temperature to afford the corresponding

Stereoselective synthesis of hernandulcin, peroxylippidulcine A, lippidulcines A, B and C and taste evaluation

• Marco G. Rigamonti and
• Francesco G. Gatti

Beilstein J. Org. Chem. 2015, 11, 2117–2124, doi:10.3762/bjoc.11.228

• oxidative dehydrogenation. Then we tested another procedure, in which the co-oxidant O2 was replaced with Oxone [29], but even in this case the conversion (6% by GC) was worse than that achieved using bubbling O2. Further attempts of optimizing the oxidative dehydrogenative step of the Stahl protocol were

Design and synthesis of polycyclic sulfones via Diels–Alder reaction and ring-rearrangement metathesis as key steps

• Sambasivarao Kotha and
• Rama Gunta

Beilstein J. Org. Chem. 2015, 11, 1373–1378, doi:10.3762/bjoc.11.148

• , commercially available as Oxone®) in aqueous methanol. Equipped with this information, oxidation of compound 5 was attempted under similar reaction conditions to get the desired sulfone 6 [33] (Scheme 1, Table 1). Initially, when the reaction was carried out at 0 °C, the epoxy sulfone 7 was the major product

Pd(OAc)₂-catalyzed dehydrogenative C–H activation: An expedient synthesis of uracil-annulated β-carbolinones

• Biplab Mondal,
• Somjit Hazra,
• Tarun K. Panda and
• Brindaban Roy

Beilstein J. Org. Chem. 2015, 11, 1360–1366, doi:10.3762/bjoc.11.146

• % yield of 5a with 52% conversion of starting material. Increasing the temperature to 90 °C (Table 1, entry 2) afforded 63% yield of 5a with 80% conversion of 4a. Then different oxidants [Cu(OTf)2, PhI(OAc)2, K2S2O8, (NH4)2S2O8, p-benzoquinone (BQ), oxone, AgOAc, molecular oxygen] were examined under

• these reaction conditions. With Cu(OTf)2 (Table 1, entry 3) and oxone (Table 1, entry 8), total recovery of starting material was observed while PhI(OAc)2 (Table 1, entry 4), (NH4)2S2O8 (Table 1, entry 6) showed total decomposition of starting material. With BQ the yield was almost the same (65%) as

Intermolecular addition reactions of N-alkyl-N-chlorosulfonamides to unsaturated compounds

• Gerold Heuger and
• Richard Göttlich

Beilstein J. Org. Chem. 2015, 11, 1226–1234, doi:10.3762/bjoc.11.136

• ], which produced the corresponding N-chloro compounds 2a and 2b in quantitative yield (Scheme 1). Other procedures for the synthesis of these compounds including N-chlorination with an fivefold excess of Oxone® in the presence of NaCl/Al2O3 [35] or deprotonation and reaction with NCS [36][37] did not lead

Azobenzene-based inhibitors of human carbonic anhydrase II

• Leander Simon Runtsch,
• David Michael Barber,
• Peter Mayer,
• Michael Groll,
• Dirk Trauner and
• Johannes Broichhagen

Beilstein J. Org. Chem. 2015, 11, 1129–1135, doi:10.3762/bjoc.11.127

• compounds were generated that were all used without further purification for the following condensation reactions. For example, sulfanilamide reacted with Oxone® in a biphasic DCM/water mixture to its nitroso counterpart, which was condensed with p-toluidine to give methyl azobenzene 1f (Scheme 1c) in 45

A simple and efficient method for the preparation of 5-hydroxy-3-acyltetramic acids

• Johanna Trenner and
• Evgeny V. Prusov

Beilstein J. Org. Chem. 2015, 11, 323–327, doi:10.3762/bjoc.11.37

• briefly tested, but were found to produce rather mediocre yields of hydroxylated compounds. Attempted oxidations with Oxone or air gave no product at all. Our efforts to improve the yield of the desired product by variation of reaction conditions were rather fruitless, and therefore, our attention was

Electrochemical selenium- and iodonium-initiated cyclisation of hydroxy-functionalised 1,4-dienes

• Philipp Röse,
• Steffen Emge,
• Jun-ichi Yoshida and
• Gerhard Hilt

Beilstein J. Org. Chem. 2015, 11, 174–183, doi:10.3762/bjoc.11.18

• organic trihalide salts [30], N-bromosuccinimide or N-iodosuccinimide and its derivatives [31][32][33][34][35][36], or more specialised reagents such as bis(pyridinium)iodonium(I) tetrafluoroborate [37][38][39]. Next to those, the in situ oxidation of halogenide ions with strong oxidants such as oxone, Pb

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

• lower temperature (50 °C instead of 100 °C, as in the case of CH-reagents 22 and 23) [53]. The ortho-acetoxylation and methoxylation of O-methyl aryl oximes 31 with Pd(OAc)2 combined with such oxidants as oxone, potassium persulfate, and (diacetoxyiodo)benzene (Scheme 7, coupling products 32 and 33

• in a basic medium [173]. The oxidative esterification of aldehydes was performed using peroxides in the presence of Lewis acids or in the absence of the latter; for example, using oxone in the presence of In(OTf)3 [174][175], oxone [174][176], Caro’s acid [177], H2O2aq (30%) in the presence of CaCl2

Magnesium bis(monoperoxyphthalate) hexahydrate as mild and efficient oxidant for the synthesis of selenones

• Andrea Temperini,
• Massimo Curini,
• Ornelio Rosati and
• Lucio Minuti

Beilstein J. Org. Chem. 2014, 10, 1267–1271, doi:10.3762/bjoc.10.127

• of phenylseleninic acid [5]. These methods suffer of several disadvantages such as harsh reaction conditions and limited structural features of the substrates; thus, potassium hydrogen persulfate [6] (Oxone) and m-chloroperoxybenzoic acid [4][7] (MCPBA) have been employed for the oxidation of

• other hand the oxidation of 1b with Oxone in methanol and water gave the β-methoxy alcohol through transformation of the C–Se bond into a C–O bond even in the presence of a weak nucleophile like the hydroxy ion [6]. The oxidation of γ-(phenylseleno)alkyl tosylamide 1d with MMPP (2.4 equiv) in ethanol

• -heterocyclic compounds 3d and 3f–j are not obtained when Oxone [6] is employed as oxidant. In these cases the products obtained were the corresponding selenoxides and the β-elimination products. Conclusion In summary, compared to the widely used oxidant MCPBA, MMPP is cheap, stable in the solid state, safer in

Heronapyrrole D: A case of co-inspiration of natural product biosynthesis, total synthesis and biodiscovery

• Jens Schmidt,
• Zeinab Khalil,
• Robert J. Capon and
• Christian B. W. Stark

Beilstein J. Org. Chem. 2014, 10, 1228–1232, doi:10.3762/bjoc.10.121

• effect an epoxidation of 8. Application of substoichiometric amounts of oxidant (Oxone®) delivered the isomeric mono-epoxides 9 and 10 as the main constituents, along with minor amounts of the bis-epoxide 11. Of note, on work-up 9 was observed to undergo partial cyclization to the desired tetrahydrofuran

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

• , Oxone (Table 3, entry 2) shows 94% conversion of 1a in 2 h. In case of 50% Hydrogen peroxide (Table 3, entry 3), more than 7 equivalents of oxidant were required with successive addition. The urea hydrogen peroxide shows moderate conversion in 20 h (Table 3, entry 6). The other diperoxy acids like

• was surmised that in the presence of oxidant these substrates form a diimine type product (similar to oxidative hair dye mechanism) [33], which makes the ring unreactive towards electrophilic substitution. Since Oxone and 50% hydrogen peroxide showed good results with substrate 1a, we have checked the

• applicability of these two oxidants for the bromination of some substrates listed in Table 4. The bromination of substrate 1b using Oxone as an oxidant required 14 h for complete conversion at room temperature. Whereas, the substrate 1g did not show complete conversion in 24 h at room temperature as well as at

Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products

• Alexander O. Terent'ev,
• Dmitry A. Borisov,
• Vera A. Vil’ and
• Valery M. Dembitsky

Beilstein J. Org. Chem. 2014, 10, 34–114, doi:10.3762/bjoc.10.6

Cyclization of substitued 2-(2-fluorophenylazo)azines to azino[1,2-c]benzo[d][1,2,4]triazinium derivatives

• Aleksandra Jankowiak,
• Emilia Obijalska and
• Piotr Kaszynski

Beilstein J. Org. Chem. 2013, 9, 1873–1880, doi:10.3762/bjoc.9.219

• , CH2Cl2, rt, 25 h; ii) toluene, 50% NaOH, 50 °C, 25 min; iii) NCS, Me2S, CH2Cl2, –20 °C; iv) mCPBA, CH2Cl2, 0 °C; v) Oxone®, CH2Cl2/H2O rt, 25 h. Formation of cations 1 from diazenes 4. Calculated free energy activation and change (kcal/mol) for the cyclization of cis-azopyridine 4-Z to the nonaromatic

From bead to flask: Synthesis of a complex β-amido-amide for probe-development studies

• Kevin S. Martin,
• Cristian Soldi,
• Kellan N. Candee,
• Hiromi I. Wettersten,
• Robert H. Weiss and
• Jared T. Shaw

Beilstein J. Org. Chem. 2013, 9, 260–264, doi:10.3762/bjoc.9.31

• benzimidazole formation with Oxone furnished benzimidazole 17 in 47% yield over two steps [20][21]. The ester of 17 was smoothly reduced to the alcohol 18, in 74% yield, and immediately oxidized to the aldehyde 4, in 87% yield. Unfortunately, 4 produced none of the desired β-amino acid 3 under several different

• this reaction was significantly lower, less than 50%, compared to the reaction to produce 14, and we observed some transesterification of the methyl ester with butanol to produce a mixture of 27 and the butyl ester of 27 as the major products (not shown). We thus turned to using Oxone, and

The crystal structure of the Dess–Martin periodinane

• Albert Schröckeneder,
• Desiree Stichnoth,
• Peter Mayer and
• Dirk Trauner

Beilstein J. Org. Chem. 2012, 8, 1523–1527, doi:10.3762/bjoc.8.172

• usually prepared from 2-iodobenzoic acid (2) in a two-step procedure, which involves oxidation with Oxone (a formulation of peroxomonosulfate) [5], followed by heating of the intermediary iodine(V) species IBX (3) with acetic anhydride and catalytic amounts of p-toluenesulfonic acid [6]. Upon repeating

• this procedure with an older and less-active batch of Oxone, we obtained well-defined single crystals of acetoxy-1,2-benziodoxolin-3-one (4) as a byproduct. We quickly established that the crystal structure of this partially oxidized compound had already been described by Gougoutas and Clardy four

• to rotate along the acetate C–C bonds to best fit the experimental electron density. CCDC 866010. 1-Hydroxy-1,2-benziodoxol-3(1H)-one (IBX) (3): 2-iodobenzoic acid (100 g, 403 mmol) was added to a solution of Oxone (2KHSO5/KHSO4/K2SO4) (322 g, 524 mmol) in water (2 L) and stirred at 80 °C for 4 h

Metathesis access to monocyclic iminocyclitol-based therapeutic agents

• Ileana Dragutan,
• Valerian Dragutan,
• Carmen Mitan,
• Hermanus C.M. Vosloo,
• Lionel Delaude and
• Albert Demonceau

Beilstein J. Org. Chem. 2011, 7, 699–716, doi:10.3762/bjoc.7.81

• : 2,2-dimethoxypropane, PPTS, acetone, r.t. Step e: H2SO4, 1,4-dioxane, H2O, reflux. Step f: K2OsO4·2H2O, NMO, acetone, H2O, r.t. Step g: HCl, MeOH. Step h: Oxone, CF3COCH3, NaHCO3, aqueous Na2·EDTA, CH3CN, 0 °C. Step i: 0.3 M KOH, 1,4-dioxane, H2O, reflux]. Synthesis of L-1-deoxyaltronojirimycin (96

Rh-Catalyzed rearrangement of vinylcyclopropane to 1,3-diene units attached to N-heterocycles

• Franca M. Cordero,
• Carolina Vurchio,
• Stefano Cicchi,
• Armin de Meijere and
• Alberto Brandi

Beilstein J. Org. Chem. 2011, 7, 298–303, doi:10.3762/bjoc.7.39

• Discussion The tetrahydropyridones employed in this study were prepared according to published procedures with slight modifications. In particular, oxidation of the tetrahydroquinoline 5 with oxone [38] afforded the nitrone 6 [39][40][41] in 66% yield (Scheme 2, see Supporting Information File 1 for full

Oxidative cyclization of alkenols with Oxone using a miniflow reactor

• Yoichi M. A. Yamada,
• Kaoru Torii and
• Yasuhiro Uozumi

Beilstein J. Org. Chem. 2009, 5, No. 18, doi:10.3762/bjoc.5.18

• Yoichi M. A. Yamada Kaoru Torii Yasuhiro Uozumi RIKEN, Hirosawa, Wako, Saitama 351-0198, Japan Institute for Molecular Science (IMS), Myodaiji, Okazaki, Aichi 444-8787, Japan 10.3762/bjoc.5.18 Abstract A miniflow system for oxidative cyclization of alkenols with Oxone was developed. Thus, the

• oxidative cyclization of (Z)- and (E)-alkenols in i-PrOH with an aqueous solution of Oxone proceeded smoothly and safely in a PTFE tube without any exogenous catalytic species, and was subsequently quenched in a flow-reaction manner to afford the corresponding furanyl and pyranyl carbinols quantitatively

• within 5 or 10 min of residence time. Keywords: alkenols; cyclic ethers; miniflow reaction; oxidative cyclization; Oxone; Introduction The development of flow-reaction systems for molecular transformations is an important goal in organic syntheses. Recently, innovative devices such as micro- and