The EIMS fragmentation mechanisms of the sesquiterpenes corvol ethers A and B, epi-cubebol and isodauc-8-en-11-ol

• Patrick Rabe and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2016, 12, 1380–1394, doi:10.3762/bjoc.12.132

• , introduction of labelling into the various positions of the compound of interest may require a different synthetic strategy for each individual target isotopomer. Most of these studies made use of deuterium labellings that can frequently be introduced into reactive positions of a (functionalised) terpene

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

• functionalized substrates. In contrast, our lab has developed a new synthetic strategy starting from an acid chloride and tris(trimethylsilyl) phosphite, followed by a methanolysis step [15]. This one-pot procedure allows the synthesis of various aliphatic and aromatic bisphosphonic acids under mild conditions

• . Bifunctional PEG-HMBPs 1. Direct methods for the 1-hydroxyalkylidenebisphosphonic acid synthesis. Synthetic strategy of PEG-HMBPs 1. Synthesis of PEG-HMBPs 1 and 1’. Syntheses of HMBP-PEG-N3 16 and HMBP-PEG-NH3+ 17. Synthesis of HMBP-PEG-COOH 23. Synthesis of PEG-HMBPs 1,1’and 10. Supporting Information

• critical due to its high sensitivity under harsh conditions. Wherefore, our methodology, which exhibits a high tolerance to various functionalized groups, appears to be an adequate way to introduce the HMBP chain in presence of the PEG moiety. To obtain the PEG-HMBP 1 compound family, the synthetic

Palladium-catalyzed picolinamide-directed iodination of remote ortho-C−H bonds of arenes: Synthesis of tetrahydroquinolines

• William A. Nack,
• Xinmou Wang,
• Bo Wang,
• Gang He and
• Gong Chen

Beilstein J. Org. Chem. 2016, 12, 1243–1249, doi:10.3762/bjoc.12.119

• many natural products and pharmaceutical agents [1][2]. Efficient and generally applicable methods for the synthesis of THQs with complex substitution patterns are still in great demand [3][4][5][6][7]. Recently, we reported a synthetic strategy for THQs based on picolinamide (PA)-directed sequential C

• diverse substitution patterns from readily accessible starting materials. New synthetic strategy for THQs via PA-directed C−H functionalization. Preparation of iodo-substituted THQs via PA-directed C−H functionalization strategy. a) ArI (2 equiv), Pd(OAc)2 (10 mol %), (BnO)2PO2H (20 mol %), Ag2CO3 (1.5

NeoPHOX – a structurally tunable ligand system for asymmetric catalysis

• Jaroslav Padevět,
• Marcus G. Schrems,
• Robin Scheil and
• Andreas Pfaltz

Beilstein J. Org. Chem. 2016, 12, 1185–1195, doi:10.3762/bjoc.12.114

• anions were omitted for clarity. Retrosynthetic analysis for NeoPHOX ligands. Synthesis of 1st generation NeoPHOX Ir-complexes [19]. Synthesis of a C(5)-disubstituted NeoPHOX-Ir complex. Revisited synthetic strategy for the preparation of a threonine-based NeoPHOX ligand. Undesired β-lactam formation

• . Synthetic strategy for the synthesis of the serine-derived NeoPHOX ligand. Derivatization of the 2nd generation NeoPHOX ligands and formation of their iridium complexes. Asymmetric palladium-catalyzed allylic substitution with rac-(E)-1,3-diphenylallyl acetate. Asymmetric palladium-catalyzed allylic

Synthesis of 2-oxindoles via 'transition-metal-free' intramolecular dehydrogenative coupling (IDC) of sp² C–H and sp³ C–H bonds

• Nivesh Kumar,
• Santanu Ghosh,
• Subhajit Bhunia and
• Alakesh Bisai

Beilstein J. Org. Chem. 2016, 12, 1153–1169, doi:10.3762/bjoc.12.111

• C−H functionalization is an attractive synthetic strategy used in organic synthesis for the development of atom- and step-economical routes [1][2][3][4][5][6][7][8][9][10]. In recent years it was witnessed a mushrooming growth in the number of reports in the literature owing to the efficiency of the

Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization

• Barry M. Trost,
• Michael C. Ryan and
• Meera Rao

Beilstein J. Org. Chem. 2016, 12, 1136–1152, doi:10.3762/bjoc.12.110

• with this methodology. Additionally, no other attempted synthetic strategy was able to provide (R)-52, including Noyori and CBS reduction, which highlights the utility of this asymmetric transformation. In acetone, the nature of this stereocenter had very little impact on the enantiomeric ratio of the

Towards the total synthesis of keramaphidin B

• Pavol Jakubec,
• Alistair J. M. Farley and
• Darren J. Dixon

Beilstein J. Org. Chem. 2016, 12, 1096–1100, doi:10.3762/bjoc.12.104

• pronucleophile to a substituted furanyl nitroolefin catalysed by a bifunctional cinchonine-derived thiourea has been used as the key stereocontrolling step in a new synthetic strategy to the heavily functionalised piperidine core of keramaphidin B. Keywords: bifunctional organocatalyst; enantioselective Michael

• wish to report our preliminary synthetic efforts towards the stereoselective synthesis of the heavily functionalised piperidine core of keramaphidin B (1). Results and Discussion Our overall synthetic strategy is presented in Figure 2. We envisaged that a late stage alkyne RCM reaction of 2 and cis

The synthesis of functionalized bridged polycycles via C–H bond insertion

• Jiun-Le Shih,
• Po-An Chen and
• Jeremy A. May

Beilstein J. Org. Chem. 2016, 12, 985–999, doi:10.3762/bjoc.12.97

• alternative positions, or the synthetic strategy must be completely altered as the original method is not capable of synthesizing other isomers. For example, multiple research groups have shown that the bridged bicyclo[2.2.2]octane core 1 of maoecrystal V may be constructed via an intramolecular Diels–Alder

Syntheses of dibenzo[d,d']benzo[2,1-b:3,4-b']difuran derivatives and their application to organic field-effect transistors

• Minh Anh Truong and
• Koji Nakano

Beilstein J. Org. Chem. 2016, 12, 805–812, doi:10.3762/bjoc.12.79

• desired syn-DBBDF 5 was successfully synthesized via the double intramolecular cyclization under basic conditions at high temperature (92% yield) [37][43]. The same synthetic strategy was applied to the synthesis of syn-DNBDF (Scheme 2). 2-Decyl-7-methoxynaphthalene was prepared from 7-methoxynaphthalen-2

Unconventional application of the Mitsunobu reaction: Selective flavonolignan dehydration yielding hydnocarpins

• Guozheng Huang,
• Simon Schramm,
• Jörg Heilmann,
• David Biedermann,
• Vladimír Křen and
• Michael Decker

Beilstein J. Org. Chem. 2016, 12, 662–669, doi:10.3762/bjoc.12.66

• atom economics and remains the only specific application of Mitsunobu conditions for a one-pot dehydration of this important class of natural products. Structures of silibinin, isosilybin, and silychristin, and hydnocarpin-type flavonolignans. Synthetic strategy of semi-synthesis of hydnocarpins from

New synthetic strategies for xanthene-dye-appended cyclodextrins

• Milo Malanga,
• Andras Darcsi,
• Mihaly Balint,
• Gabor Benkovics,
• Tamas Sohajda and
• Szabolcs Beni

Beilstein J. Org. Chem. 2016, 12, 537–548, doi:10.3762/bjoc.12.53

• later the same group reported on a fluorescein-modified γ-CD and its properties as a sensor and as a charge-changeable receptor for detecting organic acids [13]. The synthetic strategy was still based on the ester formation between the fluorophore and the CD scaffold, but the conditions were slightly

• glass substrates. Hasegawa et al. [15] were the first to develop rhodamine labeled CDs for biological purposes. They synthesized two different fluorescent β-CDs and showed their utility as new fluorogenic probes for monitoring pH of HeLa cells. The synthetic strategy was based first on the modification

• agents for the carboxylic acid were HOBt and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC). Fang and co-workers designed a ratiometric sensor for detecting mercury ions in aqueous media, some biological fluids and living cells based on a rhodamine-modified β-CD [16]. The synthetic strategy was a

Diastereoselective synthesis of new O-alkylated and C-branched inositols and their corresponding fluoro analogues

• Charlotte Collet,
• Françoise Chrétien,
• Yves Chapleur and
• Sandrine Lamandé-Langle

Beilstein J. Org. Chem. 2016, 12, 353–361, doi:10.3762/bjoc.12.39

• catalyst. Synthesis of O-alkylated myo- and scyllo-inositol derivatives bearing a fluorinated arm The fluoro analogues of myo-1 and scyllo-1 were then prepared through a synthetic strategy that involves easily removable acetates on the inositol ring (Scheme 2, see Supporting Information File 1 for full

Cascade alkylarylation of substituted N-allylbenzamides for the construction of dihydroisoquinolin-1(2H)-ones and isoquinoline-1,3(2H,4H)-diones

• Ping Qian,
• Bingnan Du,
• Wei Jiao,
• Haibo Mei,
• Jianlin Han and
• Yi Pan

Beilstein J. Org. Chem. 2016, 12, 301–308, doi:10.3762/bjoc.12.32

• -substituted heterocycles has been considered as an efficient organic synthetic strategy, which is often featured by a new ring and dual C–C bond formation in one process [35][36][37][38][39][40][41][42]. Recently, the group of Liu reported a cascade alkylarylation of N-alkyl-N-phenylacryamide with simple

Spiro-fused carbohydrate oxazoline ligands: Synthesis and application as enantio-discrimination agents in asymmetric allylic alkylation

• Jochen Kraft,
• Martin Golkowski and
• Thomas Ziegler

Beilstein J. Org. Chem. 2016, 12, 166–171, doi:10.3762/bjoc.12.18

• order to further our investigations in asymmetric catalysis with spiro-fused oxazoline ligands, we devised a new convenient synthetic strategy. Herein we present a new straightforward synthesis of spiro-fused D-fructo- and D-psico-configurated PyOx ligands and their application in palladium-catalyzed

Solving the puzzling competition of the thermal C²–C⁶ vs Myers–Saito cyclization of enyne-carbodiimides

• Anup Rana,
• Mehmet Emin Cinar,
• Debabrata Samanta and
• Michael Schmittel

Beilstein J. Org. Chem. 2016, 12, 43–49, doi:10.3762/bjoc.12.6

• in the Myers–Saito pathway. The synthetic strategy (Scheme 3) was to first prepare carbodiimide 10 [24] according to a literature procedure. In the next step, a Sonogashira coupling between 10 and N,N-dimethylprop-2-yn-1-amine afforded the desired enyne-carbodiimide 11 in 24% yield. Thermolysis of 11

Exploring architectures displaying multimeric presentations of a trihydroxypiperidine iminosugar

• Camilla Matassini,
• Stefania Mirabella,
• Andrea Goti,
• Inmaculada Robina,
• Antonio J. Moreno-Vargas and
• Francesca Cardona

Beilstein J. Org. Chem. 2015, 11, 2631–2640, doi:10.3762/bjoc.11.282

• metabolic disorder and Helicobacter pylori infection, as well as in the elucidation of the biological role of α-L-fucosidase in spermiogenesis and sperm maturation [23]. Following our interest in the synthesis of natural alkaloids and their unnatural analogs we recently developed a straightforward synthetic

• strategy for the synthesis of diversely functionalized trihydroxypiperidines through double reductive amination of the D-mannose-derived aldehyde 2 (Scheme 1) [24][25]. Among the 1-azasugars accessed with this methodology, our attention was drawn to the enantiomer of natural 3,4,5-trihydroxypiperidine (1

Versatile synthesis and biological evaluation of novel 3’-fluorinated purine nucleosides

• Hang Ren,
• Haoyun An,
• Paul J. Hatala,
• William C. Stevens Jr,
• Jingchao Tao and
• Baicheng He

Beilstein J. Org. Chem. 2015, 11, 2509–2520, doi:10.3762/bjoc.11.272

• University of Chicago Medical Center, Chicago, Illinois 60637, USA 10.3762/bjoc.11.272 Abstract A unified synthetic strategy accessing novel 3'-fluorinated purine nucleoside derivatives and their biological evaluation were achieved. Novel 3’-fluorinated analogues were constructed from a common 3’-deoxy-3

• analogs of natural products nebularine and 6-methylpurine riboside were constructed via our convergent synthetic strategy. Synthesized nucleosides were tested against HT116 (colon cancer) and 143B (osteosarcoma cancer) tumor cell lines. We have demonstrated 3’-fluorine purine nucleoside analogues display

• furnish 3’-deoxy-3’-fluoroadenosine (2) in 85% yield. Our synthetic strategy provided compound 2 in excellent yield (76%, 2 steps) compared to previously reported literature protocols (3.5%, 8 steps) [31][32]. The 6-chlorine of compound 26 was replaced by hydroxylamine, with concomitant removal of the

Syntheses of 2-substituted 1-amino-4-bromoanthraquinones (bromaminic acid analogues) – precursors for dyes and drugs

• Enas M. Malik,
• Younis Baqi and
• Christa E. Müller

Beilstein J. Org. Chem. 2015, 11, 2326–2333, doi:10.3762/bjoc.11.253

• the potential hydrogen donor for the reaction [64][65]. Therefore, we re-designed our synthetic strategy to start with compounds lacking bromine at position 4 and only introducing the bromine atom in the last step (Scheme 3). Accordingly, compound 5 was converted to 1-amino-2-cyanoanthraquinone (12

Beyond catalyst deactivation: cross-metathesis involving olefins containing N-heteroaromatics

• Kevin Lafaye,
• Cyril Bosset,
• Lionel Nicolas,
• Amandine Guérinot and
• Janine Cossy

Beilstein J. Org. Chem. 2015, 11, 2223–2241, doi:10.3762/bjoc.11.241

• ). As the use of a large excess of the functionalized alkene partner 71 was not attractive, the authors revised their synthetic strategy and finally installed the triene moiety by means of a double benzoyloxysulfone elimination applied to compound 76 which was prepared from aldehyde 77 (Scheme 29

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

• the synthesis of hernadulcin and its hydroxy derivatives, i.e., the lippidulcines A, B and C and their taste evaluation. Results and Discussion Since our synthetic strategy for the preparation of lippidulcines 3a–c is based on the photooxygenation of 1, it was mandatory to develop and optimize the

[2.2]Paracyclophane derivatives containing tetrathiafulvalene moieties

• Laura G. Sarbu,
• Lucian G. Bahrin,
• Peter G. Jones,
• Lucian M. Birsa and
• Henning Hopf

Beilstein J. Org. Chem. 2015, 11, 1917–1921, doi:10.3762/bjoc.11.207

• are known to provide tetrathiafulvalenes under specific conditions [11][12][13]. The synthetic strategy for the incorporation of the 1,3-dithiol-2-ylium ring in the [2.2]paracyclophane framework involves a three-step reaction sequence, starting from 4-acetyl[2.2]paracyclophane (1) (Scheme 1). The

Design and synthesis of propellane derivatives and oxa-bowls via ring-rearrangement metathesis as a key step

• Sambasivarao Kotha and
• Rama Gunta

Beilstein J. Org. Chem. 2015, 11, 1727–1731, doi:10.3762/bjoc.11.188

• -quinones (p-benzoquinone, 1,4-naphthoquinone or 1,4-anthraquinone) with a freshly cracked cyclopentadiene. To realize the synthetic strategy (Figure 1) to various propellane derivatives [29][30][31] and oxa-bowls, we commenced with the preparation of a known DA adduct 3a [32]. Subsequent allylation of 3a

Pyridinoacridine alkaloids of marine origin: NMR and MS spectral data, synthesis, biosynthesis and biological activity

• Louis P. Sandjo,
• Victor Kuete and
• Maique W. Biavatti

Beilstein J. Org. Chem. 2015, 11, 1667–1699, doi:10.3762/bjoc.11.183

• imine formation and aromatization, occurred presumably due to the presence of an acidic solvent. Styelsamine B (4) was obtained with an overall yield of 35%. This pyridinium salt was treated with an ampholyte to afford its neutral form cystodytin J (Scheme 1) [58]. This biomimetic synthetic strategy is

A facile synthetic route to benzimidazolium salts bearing bulky aromatic N-substituents

• Gabriele Grieco,
• Olivier Blacque and
• Heinz Berke

Beilstein J. Org. Chem. 2015, 11, 1656–1666, doi:10.3762/bjoc.11.182

• -substituents, where one of the N-substituent is an aromatic or a benzylic group and the other substituent an alkyl [25][26][27][28][29][30] or benzyl [31][32] group. A synthetic strategy for the preparation of sterically demanding monoaryl benzimidazolium salts starts from the corresponding benzimidazoles

Towards inhibitors of glycosyltransferases: A novel approach to the synthesis of 3-acetamido-3-deoxy-D-psicofuranose derivatives

• Maroš Bella,
• Miroslav Koóš and
• Chun-Hung Lin

Beilstein J. Org. Chem. 2015, 11, 1547–1552, doi:10.3762/bjoc.11.170

• -configuration at the anomeric atom C1 was established on the basis of inspection of the relevant torsion angles (Table 2). Conclusion In summary, a new synthetic strategy leading to the formation of a 3-acetamido-3-deoxy-D-psicofuranose frame is presented. The attempted thioglycosylation of fully protected 3

• Maros Bella Miroslav Koos Chun-Hung Lin Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38, Bratislava, Slovakia Institute of Biological Chemistry, Academia Sinica, No. 128 Academia Road Sec. 2, Taipei 11529, Taiwan 10.3762/bjoc.11.170 Abstract A novel synthetic

• strategy leading to 3-acetamido-3-deoxy-D-psicofuranose 9 is presented. The latter compound, after some manipulations, was transformed into fully protected 3-acetamido-3-deoxy-D-psicofuranose 11 as a potential substrate for the synthesis of N-acetylglucosaminyltransferase inhibitors designed by