Elucidation of the regio- and chemoselectivity of enzymatic allylic oxidations with Pleurotus sapidus – conversion of selected spirocyclic terpenoids and computational analysis

• Verena Weidmann,
• Mathias Schaffrath,
• Holger Zorn,
• Julia Rehbein and
• Wolfgang Maison

Beilstein J. Org. Chem. 2013, 9, 2233–2241, doi:10.3762/bjoc.9.262

• ; natural products; terpenes; Introduction Selective oxidations of CH-bonds are attractive synthetic transformations with a broad spectrum of applications in academia and a high impact on the industrial chemical value chain as they convert relatively cheap precursors into value-added products [1][2]. Among

Flexible synthesis of anthracycline aglycone mimics via domino carbopalladation reactions

• Markus Leibeling and
• Daniel B. Werz

Beilstein J. Org. Chem. 2013, 9, 2194–2201, doi:10.3762/bjoc.9.258

• lack of efficient synthetic approaches to anthracyclines many industrial approaches still rely on the use of recombinant microorganisms with a mutated gene of the anthracycline metabolism [9]. Different convenient synthetic transformations involve the application of a Diels–Alder reaction as key step

The chemistry of amine radical cations produced by visible light photoredox catalysis

• Jie Hu,
• Jiang Wang,
• Theresa H. Nguyen and
• Nan Zheng

Beilstein J. Org. Chem. 2013, 9, 1977–2001, doi:10.3762/bjoc.9.234

• synthetic transformations to produce a diverse array of amines. Moreover, visible light photoredox catalysis has been merged with other types of catalysis, including enamine catalysis, N-heterocyclic carbene (NHC) catalysis, or copper acetylide formation. This dual catalysis approach has significantly

One-step synthesis of pyridines and dihydropyridines in a continuous flow microwave reactor

• Mark C. Bagley,
• Vincenzo Fusillo,
• Robert L. Jenkins,
• M. Caterina Lubinu and
• Christopher Mason

Beilstein J. Org. Chem. 2013, 9, 1957–1968, doi:10.3762/bjoc.9.232

• synthetic transformations (Scheme 1), including Bohlmann–Rahtz cyclodehydration of aminodienones 1 to the corresponding pyridines 2 [44][45], Fischer indole synthesis of tetrahydrocarbazole 5 from phenylhydrazine (3) and cyclohexanone (4) [44], and hydrolysis of 4-chloromethylthiazole (6) to give the

An organocatalytic route to 2-heteroarylmethylene decorated N-arylpyrroles

• Alexandre Jean,
• Jérôme Blanchet,
• Jacques Rouden,
• Jacques Maddaluno and
• Michaël De Paolis

Beilstein J. Org. Chem. 2013, 9, 1480–1486, doi:10.3762/bjoc.9.168

• be expected to follow (Scheme 5). Having established a practical methodology for the preparation of substituted N-arylpyrroles, we next undertook synthetic transformations to extend the molecular diversity of the substrates. While attempts to perform an oxidation of the bis(heteroaryl)methylene

Transition-metal and organocatalysis in natural product synthesis

• David Yu-Kai Chen and
• Dawei Ma

Beilstein J. Org. Chem. 2013, 9, 1192–1193, doi:10.3762/bjoc.9.134

• synthesis in the interrogation of biological processes, elucidation of biogenetic origins, structural assignments and many others, its fundamental and indispensable value as a vehicle for the discovery of new synthetic transformations is well-testified and unparalleled by any other research discipline over

Appel-reagent-mediated transformation of glycosyl hemiacetal derivatives into thioglycosides and glycosyl thiols

• Tamashree Ghosh,
• Abhishek Santra and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2013, 9, 974–982, doi:10.3762/bjoc.9.112

• various thiooligosaccharides, glycoproteins and glycolipids [28][29][30][31][32]. The anomeric configurations of glycosyl thiols mostly remain unaffected in comparison to the glycosyl hemiacetal derivatives during their synthetic transformations [4]. Glycosyl thiol derivatives act as precursors for the

Diastereoselective synthesis of nitroso acetals from (S,E)-γ-aminated nitroalkenes via multicomponent [4 + 2]/[3 + 2] cycloadditions promoted by LiCl or LiClO₄

• Leandro Lara de Carvalho,
• Robert Alan Burrow and
• Vera Lúcia Patrocinio Pereira

Beilstein J. Org. Chem. 2013, 9, 838–845, doi:10.3762/bjoc.9.96

• as 3 (R2 = alkyl) were employed in various synthetic transformations [6][7] (Scheme 1). In addition, Denmark’s group and others investigated the tandem [4 + 2]/[3 + 2] nitroalkene cycloaddition employing unactivated olefins or enol ethers as dienophiles and electron-deficient alkenes as 1,3

Intramolecular carbonickelation of alkenes

• Rudy Lhermet,
• Muriel Durandetti and
• Jacques Maddaluno

Beilstein J. Org. Chem. 2013, 9, 710–716, doi:10.3762/bjoc.9.81

• carbon–carbon bond and generate a new organometallic entity, which may subsequently undergo synthetic transformations [1][2]. Even though these reactions have been known for over 85 years [3], they have emerged as practical organometallic tools only during the past forty years, in particular through the

Carbometallation chemistry

• Ilan Marek

Beilstein J. Org. Chem. 2013, 9, 234–235, doi:10.3762/bjoc.9.27

• has emerged. Since then, reactions that result in the addition of a carbon–metal bond of an organometallic across a carbon–carbon unsaturated system, leading to a new organometallic in which the newly formed carbon–metal bond can be used for further synthetic transformations, are called

Polar reactions of acyclic conjugated bisallenes

• Reiner Stamm and
• Henning Hopf

Beilstein J. Org. Chem. 2013, 9, 36–48, doi:10.3762/bjoc.9.5

• -yielding synthetic transformations from simple substrates, are useful starting materials for the preparation of a plethora of novel organic compounds. The alkylated conjugated bisallenes 1– 3 as model systems for polar reactions. Alkylation and silylation of 2. Allylation of the monoanion 4. Metalation

Organocatalytic asymmetric addition of malonates to unsaturated 1,4-diketones

• Sergei Žari,
• Tiiu Kailas,
• Marina Kudrjashova,
• Mario Öeren,
• Ivar Järving,
• Toomas Tamm,
• Margus Lopp and
• Tõnis Kanger

Beilstein J. Org. Chem. 2012, 8, 1452–1457, doi:10.3762/bjoc.8.165

• groups in the course of further synthetic transformations its main role is to provide the addition products with high ee value. The conditions for the reaction remained the same as they were in the catalyst screening experiments, except that a smaller excess of malonate (3 equiv, unless stated otherwise

• yields (up to 99%) and in high enantioselectivities (up to 93%). This enantioselective 1,4-addition to unsaturated 1,4-diketones affords valuable intermediates for further synthetic transformations. The conjugated addition to unsaturated 1,4-diketone 1. Organocatalysts screened. Proposed transition state

Organocatalytic asymmetric allylic amination of Morita–Baylis–Hillman carbonates of isatins

• Hang Zhang,
• Shan-Jun Zhang,
• Qing-Qing Zhou,
• Lin Dong and
• Ying-Chun Chen

Beilstein J. Org. Chem. 2012, 8, 1241–1245, doi:10.3762/bjoc.8.139

• electron-withdrawing groups exhibited a slower reaction rate, but both good yields and ee values were still obtained (Table 2, entries 5–10). As outlined in Scheme 2, some synthetic transformations were conducted with the multifunctional allylic amination product 4d. The N–O bond cleavage of 4d could be

• transformations of MBH carbonates of isatins are under way in our laboratory. Allylic amination of MBH carbonates of isatins to access 3-amino-2-oxindoles. Synthetic transformations of multifunctional product 4d. Screening studies of asymmetric allylic amination of MBH carbonate of isatin.a Substrate scope and

Stereoselective, nitro-Mannich/lactamisation cascades for the direct synthesis of heavily decorated 5-nitropiperidin-2-ones and related heterocycles

• Pavol Jakubec,
• Dane M. Cockfield,
• Madeleine Helliwell,
• James Raftery and
• Darren J. Dixon

Beilstein J. Org. Chem. 2012, 8, 567–578, doi:10.3762/bjoc.8.64

• materials with imines (cyclic or acyclic, preformed or formed in situ) as a key step. Not only could this approach allow the rapid generation of structural complexity, but the products would be amenable to further synthetic transformations. Furthermore, the γ-nitro ester starting materials are accessible in

Regioselectivity in the multicomponent reaction of 5-aminopyrazoles, cyclic 1,3-diketones and dimethylformamide dimethylacetal under controlled microwave heating

• Kamal Usef Sadek,
• Ramadan Ahmed Mekheimer,
• Tahany Mahmoud Mohamed,
• Moustafa Sherief Moustafa and
• Mohamed Hilmy Elnagdi

Beilstein J. Org. Chem. 2012, 8, 18–24, doi:10.3762/bjoc.8.3

• - or regioselectivity, or both, due to the several possible parallel reaction pathways, which result in the formation of different products [8][9][10]. Many factors modulate the selectivity of synthetic transformations, such as temperature, pressure, solvent, catalyst and type of reaction control, i.e

Bromine–lithium exchange: An efficient tool in the modular construction of biaryl ligands

• Laurence Bonnafoux,
• Frédéric R. Leroux and
• Françoise Colobert

Beilstein J. Org. Chem. 2011, 7, 1278–1287, doi:10.3762/bjoc.7.148

• certainly one of the most fundamental synthetic transformations [39]. Although this reaction was reported by C. S. Marvel in 1927 [40], G. Wittig [41] and H. Gilman [42][43][44] were the first to apply it in organic synthesis in the late thirties. Since then, this reaction has been considered as a mature

Synthesis of novel 5-alkyl/aryl/heteroaryl substituted diethyl 3,4-dihydro-2H-pyrrole-4,4-dicarboxylates by aziridine ring expansion of 2-[(aziridin-1-yl)-1-alkyl/aryl/heteroaryl-methylene]malonic acid diethyl esters

• Satish S. More,
• T. Krishna Mohan,
• Y. Sateesh Kumar,
• U. K. Syam Kumar and
• Navin B. Patel

Beilstein J. Org. Chem. 2011, 7, 831–838, doi:10.3762/bjoc.7.95

• -vinyl substituted aziridines; ring expansion; sodium iodide; Introduction Vinylaziridines are a particularly interesting class of aziridine derivatives that lend themselves to a host of highly useful synthetic transformations [1]. They are versatile electrophiles and notably undergo regioselective ring

Fine-tuning alkyne cycloadditions: Insights into photochemistry responsible for the double-strand DNA cleavage via structural perturbations in diaryl alkyne conjugates

• Wang-Yong Yang,
• Samantha A. Marrone,
• Nalisha Minors,
• Diego A. R. Zorio and
• Igor V. Alabugin

Beilstein J. Org. Chem. 2011, 7, 813–823, doi:10.3762/bjoc.7.93

• photochemistry open an additional dimension for the control of chemical reactivity by enabling many, otherwise impossible, synthetic transformations, but this mode of activation also provides useful spatial and temporal control of chemical processes that are required to occur in the right place and at the right

Unusual behavior in the reactivity of 5-substituted-1H-tetrazoles in a resistively heated microreactor

• Bernhard Gutmann,
• Toma N. Glasnov,
• Tahseen Razzaq,
• Walter Goessler,
• Dominique M. Roberge and
• C. Oliver Kappe

Beilstein J. Org. Chem. 2011, 7, 503–517, doi:10.3762/bjoc.7.59

• intensification; Introduction Microreactor technology has opened up new avenues for synthetic organic chemistry [1][2][3][4][5][6] and the chemical manufacturing industry [7][8]. Traditionally, most synthetic transformations performed in microreactors have involved ambient or even low-temperature conditions in

• continuous flow processes is becoming increasingly important. In the past few years our research group [19][20][21][22][23][24][25] has reported a number of successful case studies where initial reaction optimization for a variety of synthetic transformations was performed under batch microwave conditions

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

• compared to complex natural products, only a limited repertoire of synthetic transformations are utilised for their construction. Furthermore, many of the modern pioneering developments in organic synthesis including new highly selective and mild bond forming reactions such as metathesis and C–H activation

Molecular rearrangements of superelectrophiles

• Douglas A. Klumpp

Beilstein J. Org. Chem. 2011, 7, 346–363, doi:10.3762/bjoc.7.45

• nucleophiles, such as arenes and alkanes. This has led to the development of several new synthetic transformations leading to the functionalization of alkanes. Moreover, superelectrophiles have been used to prepare a wide variety of functionalized arenes. Many types of Friedel–Crafts type reactions have been

Surfactant catalyzed convenient and greener synthesis of tetrahydrobenzo[a]xanthene-11-ones at ambient temperature

• Pravin V. Shinde,
• Amol H. Kategaonkar,
• Bapurao B. Shingate and
• Murlidhar S. Shingare

Beilstein J. Org. Chem. 2011, 7, 53–58, doi:10.3762/bjoc.7.9

• forming surfactants as catalysts in water is widespread and has been studied for a number of different synthetic transformations/ multicomponent reactions in water [4]. Multicomponent reactions (MCRs) have emerged as an extremely powerful tool in combinatorial chemistry and drug discovery, since they

• based compounds, tetrahydrobenzo[a]xanthene-11-ones are of interest and have great potential for further synthetic transformations [16][17]. Some novel methods for the synthesis of tetrahydrobenzo[a]xanthene-11-ones via multicomponent condensation reaction have been developed and catalysts such as

Recent advances in carbocupration of α-heterosubstituted alkynes

• Ahmad Basheer and
• Ilan Marek

Beilstein J. Org. Chem. 2010, 6, No. 77, doi:10.3762/bjoc.6.77

• for useful synthetic transformations, it would be important to prepare selectively the α-isomer 8b as well (Scheme 4) [18]. As carbocupration of 7 leads to either variable amounts of the α- and β-isomers (Scheme 4) or mainly to the β-isomer (Scheme 5), the exclusive formation of the α-isomer could

Radical cascades using enantioenriched 7-azabenzonorbornenes and their applications in synthesis

• David M. Hodgson and
• Leonard H. Winning

Beilstein J. Org. Chem. 2008, 4, No. 38, doi:10.3762/bjoc.4.38

• established a stereoselective route to 3-exo-substituted 2-azabenzonorbornenes, further synthetic transformations of these adducts were addressed. Firstly, we considered that the 2-azabenzonorbornene framework could be a masked pyrrolidine: cleavage of the aromatic ring would reveal a stereodefined 2,4

Allylsilanes in the synthesis of three to seven membered rings: the silylcuprate strategy

• Asunción Barbero,
• Francisco J. Pulido and
• M. Carmen Sañudo

Beilstein J. Org. Chem. 2007, 3, No. 16, doi:10.1186/1860-5397-3-16

• particular allylsilanes have attracted considerable attention due to the increasing number of new methodologies that allow useful synthetic transformations. [1][2] Over the last decade allenes have emerged as one of the best sources for the synthesis of allylsilanes. [3] Although unactivated allenes do not