Manganese dioxide mediated one-pot synthesis of methyl 9H-pyrido[3,4-b]indole-1-carboxylate: Concise synthesis of alangiobussinine

• Jessica Baiget,
• Sabin Llona-Minguez,
• Stuart Lang,
• Simon P. MacKay,
• Colin J. Suckling and
• Oliver B. Sutcliffe

Beilstein J. Org. Chem. 2011, 7, 1407–1411, doi:10.3762/bjoc.7.164

• costs and in addition has the advantage that there is less waste associated with reactions of this nature and therefore less environmental impact. Taylor et al. [16][17][18][19] have shown manganese dioxide to be a robust reagent for carrying out oxidations on a wide range of activated alcohols. They

Multicomponent reaction access to complex quinolines via oxidation of the Povarov adducts

• Esther Vicente-García,
• Rosario Ramón,
• Sara Preciado and
• Rodolfo Lavilla

Beilstein J. Org. Chem. 2011, 7, 980–987, doi:10.3762/bjoc.7.110

• Povarov adducts in oxygenated atmospheres also affords the oxidation–elimination products 5 and 8 (Scheme 2) [8][12][20]. The alternative oxidation–elimination pathway is predominant in some CAN-promoted oxidations of different Povarov adducts 3. Incidentally, this reagent is also used as a catalyst in

• - and N-substituents [22][23][24][25] (for related isoquinoline oxidations, see [26][27]). Related oxidative processes involve, for instance, a cascade Povarov–hydrogen transfer reaction using Tf2NH as a catalyst and the imine as an oxidant, as recently described [28]. In addition, Povarov adducts

Gold-catalyzed oxidation of arylallenes: Synthesis of quinoxalines and benzimidazoles

• Dong-Mei Cui,
• Dan-Wen Zhuang,
• Ying Chen and
• Chen Zhang

Beilstein J. Org. Chem. 2011, 7, 860–865, doi:10.3762/bjoc.7.98

• –carbon triple bonds by homogeneous gold catalysts was reported recently [28][29][33]. To the best of our knowledge, gold and other transition metal-catalyzed oxidations of allenes have not been reported [37][38]. In the context of ongoing studies on metal-catalyzed atom-economical reactions, we have been

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

• Marcus Baumann,
• Ian R. Baxendale,
• Steven V. Ley and
• Nikzad Nikbin

Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57

Redox-active tetrathiafulvalene and dithiolene compounds derived from allylic 1,4-diol rearrangement products of disubstituted 1,3-dithiole derivatives

• Filipe Vilela,
• Peter J. Skabara,
• Christopher R. Mason,
• Thomas D. J. Westgate,
• Asun Luquin,
• Simon J. Coles and
• Michael B. Hursthouse

Beilstein J. Org. Chem. 2010, 6, 1002–1014, doi:10.3762/bjoc.6.113

• of the TTF dication hinders subsequent removal of an electron from the thiophene units, so further oxidations are beyond the electrochemical window of the solvent. Compound 28 is reversibly oxidised to 28+· at −740 mV, within the range seen in other nickel dithiolene complexes. A second single

Synthesis, electronic properties and self-assembly on Au{111} of thiolated (oligo)phenothiazines

• Adam W. Franz,
• Svetlana Stoycheva,
• Michael Himmelhaus and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2010, 6, No. 72, doi:10.3762/bjoc.6.72

• by cyclic voltammetry in the anodic region (scan area up to 1.5 V). The reversible first oxidations to the radical cations of monophenothiazines 2a, 2b, and 4 were shifted anodically in comparison to unsubstituted monophenothiazines [54] as a consequence of the electron-withdrawing nature of the

• thioacetate. Due to unsymmetrical substitution, the dyad 2c showed two distinctly separated, reversible oxidations at E00/+1 = 668 mV and E0+1/+2 = 853 mV. The cyclic voltammogram of the triad 2d displayed three distinctly separated, reversible oxidations at E00/+1 = 608 mV, E0+1/+2 = 765 mV, and E0+2/+3

• = 876 mV (Figure 2). However, the electrochemistry of the tetrad 2e is more complicated. Only three distinctly separated, reversible oxidations were evident. The first oxidations at E00/+1 = 597 mV and E0+1/+2 = 690 mV are in accordance with Nernstian behavior, while the third oxidation at E0 = 842 mV

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

• biocatalyst with respect to peracid formation, facilitating a series of oxidations including alkenes [21] and ketones via the Baeyer–Villiger reaction [22] and retaining the broad substrate specificity of Candida antarctica lipase B. In the past decade micro reactors, and more generically continuous flow

• peracid, enabling greater system flexibility, along with evaluating the methodology towards other synthetically useful oxidations. Experimental Materials 1-Methylcyclohexene (6, 99%, Aldrich), styrene (9, ReagentPlus®, ≥ 99%, Aldrich), cis-stilbene (11, 96%, Aldrich), trans-stilbene (12, 96%, Aldrich

Green oxidations: Titanium dioxide induced tandem oxidation coupling reactions

• Vineet Jeena and
• Ross S. Robinson

Beilstein J. Org. Chem. 2009, 5, No. 24, doi:10.3762/bjoc.5.24

• Information File 62: Experimental and spectroscopic data for: Green oxidations: Titanium dioxide induced tandem oxidation

A biphasic oxidation of alcohols to aldehydes and ketones using a simplified packed- bed microreactor

• Andrew Bogdan and
• D. Tyler McQuade

Beilstein J. Org. Chem. 2009, 5, No. 17, doi:10.3762/bjoc.5.17

• characterization of a simplified packed-bed microreactor using an immobilized TEMPO catalyst shown to oxidize primary and secondary alcohols via the biphasic Anelli-Montanari protocol. Oxidations occurred in high yields with great stability over time. We observed that plugs of aqueous oxidant and organic alcohol

• higher degree of safety [1][2][3][4][5][6][7][8][9][10][11][12]. Alcohol oxidations are well suited for microreactors due to high by-product formation, catalyst contamination and safety concerns often associated with scale-up in batch reactors [13]. Recent developments in microreactor technology and

• solid-supported catalysis have aimed to solve these issues. Numerous flow oxidations have been presented in the literature [13][14][15][16], however many rely on stoichiometric reagents [17][18], suffer from catalyst deactivation [19][20], or rely on soluble catalysts [21], all of which limit their

The Elbs and Boyland- Sims peroxydisulfate oxidations

• E. J. Behrman

Beilstein J. Org. Chem. 2006, 2, No. 22, doi:10.1186/1860-5397-2-22

• E. J. Behrman Department of Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA 10.1186/1860-5397-2-22 Abstract This paper reviews the recent literature on the title reactions and updates a 1988 review. The Elbs and Boyland-Sims oxidations are shown in Scheme 1

• area is the use of salts of peroxydisulfate which are soluble in organic solvents by virtue of large organic cations in place of the commercially available ammonium, sodium, or potassium salts. This approach has not yet been reported for the Elbs or Boyland-Sims oxidations. Corresponding chemistry of

• Boyland (1905–2002) has appeared. [34][35][36] The Tables record the literature on the Elbs and Boyland-Sims oxidations from 1984 (the approximate literature cutoff for ref. 1) through mid-2006. There are also a few earlier references which were omitted from ref. 1. Key to the Tables: the Tables are

Towards practical biocatalytic Baeyer- Villiger reactions: applying a thermostable enzyme in the gram- scale synthesis of optically- active lactones in a two-liquid- phase system

• Frank Schulz,
• François Leca,
• Frank Hollmann and
• Manfred T. Reetz

Beilstein J. Org. Chem. 2005, 1, No. 10, doi:10.1186/1860-5397-1-10

• shows that the thermally stable phenylacetone monooxygenase (PAMO) and recently engineered mutants can be used as a practical catalysts for enantioselective Baeyer-Villiger oxidations of several ketones on a preparative scale under in vitro conditions. For this purpose several parameters such as buffer

• composition, the nature of the solvent system and the co-factor regeneration system were optimized. Overall a fairly versatile and efficient catalytic system for enantioselective laboratory scale BV-oxidations of ketones was developed, which can easily be applied even by those organic chemists who are not

• (NAD(P)H) for reductive O2-activation.[33][34][35] Another challenge is the cost-factor of the BVMOs themselves, since their use usually requires tedious purification steps. These complications are frequently addressed by performing biocatalytic BV-oxidations in vivo, i.e., using whole, metabolically