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