AgOTf-catalyzed one-pot reactions of 2-alkynylbenzaldoximes with α,β-unsaturated carbonyl compounds

• Qiuping Ding,
• Dan Wang,
• Puying Luo,
• Meiling Liu,
• Shouzhi Pu and
• Liyun Zhou

Beilstein J. Org. Chem. 2013, 9, 1949–1956, doi:10.3762/bjoc.9.231

• processes. Isoquinoline derivatives, an important class of nitrogen-containing polycyclic heteroarenes, have attracted considerable attention because of their pharmacological activities, including antitumor, antifungal, antimalarial, antihypertensive and antihistaminic activity, and their photo- and

Synthesis and biological activities of the respiratory chain inhibitor aurachin D and new ring versus chain analogues

• Xu-Wen Li,
• Jennifer Herrmann,
• Yi Zang,
• Philippe Grellier,
• Soizic Prado,
• Rolf Müller and
• Bastien Nay

Beilstein J. Org. Chem. 2013, 9, 1551–1558, doi:10.3762/bjoc.9.176

• at an IC50 around 20 ng/mL (i.e., aurachins B, C and E, whereas aurachin D was 100- to 200-fold less active) [6]. This antimalarial activity was comparable to that of endochin (5) [13][14] and 2-methyl-4(1H)-quinolone analogues as determined in the course of important structure–activity optimization

Re₂O₇-catalyzed reaction of hemiacetals and aldehydes with O-, S-, and C-nucleophiles

• Wantanee Sittiwong,
• Michael W. Richardson,
• Charles E. Schiaffo,
• Thomas J. Fisher and
• Patrick H. Dussault

Beilstein J. Org. Chem. 2013, 9, 1526–1532, doi:10.3762/bjoc.9.174

• electron-poor amine in the presence of allyltrimethylsilane [15]. We now describe the Re2O7-promoted reactions of peroxyhemiacetals, hemiacetals, and alkoxyhydroperoxides with O-, S- and C-nucleophiles. Results In the course of investigations into potential antischistosomal and antimalarial agents [16][17

Synthesis of 2,3-dihydronaphtho[2,3-d][1,3]thiazole-4,9-diones and 2,3-dihydroanthra[2,3-d][1,3]thiazole-4,11-diones and novel ring contraction and fusion reaction of 3H-spiro[1,3-thiazole-2,1'-cyclohexanes] into 2,3,4,5-tetrahydro-1H-carbazole-6,11-diones

• Lidia S. Konstantinova,
• Kirill A. Lysov,
• Ljudmila I. Souvorova and
• Oleg A. Rakitin

Beilstein J. Org. Chem. 2013, 9, 577–584, doi:10.3762/bjoc.9.62

• -naphthoquinone structure is common for various natural products. It is associated with numerous biological activities, such as enzyme-inhibitory, antifungal, antibacterial, anticancer, antiproliferative, antiplatelet, anti-inflammatory, antiallergic, and antimalarial ones. Benzoquinones fused with heterocycles

Synthesis of meso-substituted dihydro-1,3-oxazinoporphyrins

• Satyasheel Sharma and
• Mahendra Nath

Beilstein J. Org. Chem. 2013, 9, 496–502, doi:10.3762/bjoc.9.53

• cancers [30]. Thorough literature search revealed that heterocycles containing a dihydro-1,3-oxazine ring system exhibit a wide spectrum of pharmacological activities, for example, acting as antimicrobial [31][32][33], anti-HIV [34], antimalarial [35] or antitumor agents [36][37]. By considering the

Zanthoxoaporphines A–C: Three new larvicidal dibenzo[de,g]quinolin-7-one alkaloids from Zanthoxylum paracanthum (Rutaceae)

• Fidelis N. Samita,
• Louis P. Sandjo,
• Isaiah O. Ndiege,
• Ahmed Hassanali and
• Wilber Lwande

Beilstein J. Org. Chem. 2013, 9, 447–452, doi:10.3762/bjoc.9.47

• , oxoaporphine and aporphine analogues have shown antimalarial, antitrypanosomal [24], cytotoxic [25], antioxidant [26] and larvicidal activities [20][21]. Despite the reported bioactivities, some of the oxoaporphines and aporphines have undesirable effects, for instance liriodenine is mutagenic [27] and induces

Synthesis of SF₅-containing benzisoxazoles, quinolines, and quinazolines by the Davis reaction of nitro-(pentafluorosulfanyl)benzenes

• Petr Beier and
• Tereza Pastýříková

Beilstein J. Org. Chem. 2013, 9, 411–416, doi:10.3762/bjoc.9.43

• co-workers have recently reported the synthesis of some SF5-substituted quinolines as intermediates towards analogues of the antimalarial agent mefloquine and found that some analogues had improved activity and selectivity against malaria parasites (Scheme 2) [29][30]. Results and Discussion We

The diketopiperazine-fused tetrahydro-β-carboline scaffold as a model peptidomimetic with an unusual α-turn secondary structure

• Francesco Airaghi,
• Andrea Fiorati,
• Giordano Lesma,
• Manuele Musolino,
• Alessandro Sacchetti and
• Alessandra Silvani

Beilstein J. Org. Chem. 2013, 9, 147–154, doi:10.3762/bjoc.9.17

• ]. Moreover, recently some tetracyclic β-carbolines have been described to act as selective inhibitors in the anticancer field [8][9], or to be endowed with antimalarial properties [10]. 2,5-Diketopiperazine (DKP)-based compounds are heterocyclic scaffolds structurally similar to peptides. They have attracted

• type 5 specific phosphodiesterase (PDE 5) for the treatment of erectile dysfunction (Tadalafil) [21], and the inhibition of plasmodial PDE activity for antimalarial drugs [22][23], to topoisomerase II inhibition [24], and oral antithrombotic properties [25] (Figure 1). In our ongoing program of design

Inclusion of the insecticide fenitrothion in dimethylated-β-cyclodextrin: unusual guest disorder in the solid state and efficient retardation of the hydrolysis rate of the complexed guest in alkaline solution

• Dyanne L. Cruickshank,
• Natalia M. Rougier,
• Raquel V. Vico,
• Susan A. Bourne,
• Elba I. Buján,
• Mino R. Caira and
• Rita H. de Rossi

Beilstein J. Org. Chem. 2013, 9, 106–117, doi:10.3762/bjoc.9.14

• form of a residual contact spray to control flies, mosquitoes and cockroaches. Fenitrothion has also been employed in antimalarial programmes, where spraying of houses and animal shelters with this insecticide over extended periods significantly reduced the incidence and prevalence of the disease [4

Flow photochemistry: Old light through new windows

• Jonathan P. Knowles,
• Luke D. Elliott and
• Kevin I. Booker-Milburn

Beilstein J. Org. Chem. 2012, 8, 2025–2052, doi:10.3762/bjoc.8.229

• , despite the reactor volume being only 285 µL [39]. This output was 2.6 times that of a 50 mL batch reactor. The same reactor was also successfully applied to the oxidation of allylic alcohols for the synthesis of the antimalarial artemisinin, and the conversion of α-terpinene to ascaridole. Addition of a

An efficient access to the synthesis of novel 12-phenylbenzo[6,7]oxepino[3,4-b]quinolin-13(6H)-one derivatives

• Wentao Gao,
• Guihai Lin,
• Yang Li,
• Xiyue Tao,
• Rui Liu and
• Lianjie Sun

Beilstein J. Org. Chem. 2012, 8, 1849–1857, doi:10.3762/bjoc.8.213

• tetracyclic quinoline systems on privileged templates have significant biological properties, such as antitumoral [5][6], anti-inflammatory [7], antimalarial [8], antituberculosis [9], and antiplasmodial [10] activities. Accordingly, the synthesis of new families of such quinoline systems still attracts much

Mutational analysis of a phenazine biosynthetic gene cluster in Streptomyces anulatus 9663

• Orwah Saleh,
• Katrin Flinspach,
• Lucia Westrich,
• Andreas Kulik,
• Bertolt Gust,
• Hans-Peter Fiedler and
• Lutz Heide

Beilstein J. Org. Chem. 2012, 8, 501–513, doi:10.3762/bjoc.8.57

• the first investigation of the regulatory genes of phenazine biosynthesis in Streptomyces. Keywords: phenazine; gene cluster; gene inactivation; Introduction Phenazine natural products have important biological activities comprising antibacterial, antifungal, antitumor, antimalarial, antioxidant and

Synthesis of 2-amino-3-arylpropan-1-ols and 1-(2,3-diaminopropyl)-1,2,3-triazoles and evaluation of their antimalarial activity

• Matthias D’hooghe,
• Stéphanie Vandekerckhove,
• Karen Mollet,
• Karel Vervisch,
• Stijn Dekeukeleire,
• Liesbeth Lehoucq,
• Carmen Lategan,
• Peter J. Smith,
• Kelly Chibale and
• Norbert De Kimpe

Beilstein J. Org. Chem. 2011, 7, 1745–1752, doi:10.3762/bjoc.7.205

• antiplasmodial activity against both a chloroquine-sensitive and a chloroquine-resistant strain of Plasmodium falciparum with IC50-values of ≤25 μM. Keywords: aminopropanes; antimalarial activity; aziridines; β-lactams; ring opening; Introduction Malaria remains a major issue in health control, especially in

• emergence of multiple drug resistance to clinically established antimalarial drugs, however, there is a compelling need to introduce new chemicals that can overcome this resistance. In 2007, nitrogen-analogues of glycerol, which have a long-standing tradition in medicine as β-blockers, were introduced as a

• , which were shown to be of great importance as novel antiplasmodial agents (Figure 1) [6]. More recently, we reported 1,2,3-triaminopropanes 2 as a new class of antimalarial compounds (Figure 1), prepared through microwave-assisted, regioselective ring opening of the corresponding 2-(aminomethyl

Continuous-flow hydration–condensation reaction: Synthesis of α,β-unsaturated ketones from alkynes and aldehydes by using a heterogeneous solid acid catalyst

• Magnus Rueping,
• Teerawut Bootwicha,
• Hannah Baars and
• Erli Sugiono

Beilstein J. Org. Chem. 2011, 7, 1680–1687, doi:10.3762/bjoc.7.198

• large number of important biologically active compounds. They show pharmacological properties such as antimalarial, antitumor, antiviral, and anti-inflammatory activities [55][56][57][58][59][60]. They are also well known to be key intermediates in the synthesis of flavones, flavonoids, isoflavonoids

Triple-channel microreactor for biphasic gas–liquid reactions: Photosensitized oxygenations

• Ram Awatar Maurya,
• Chan Pil Park and
• Dong-Pyo Kim

Beilstein J. Org. Chem. 2011, 7, 1158–1163, doi:10.3762/bjoc.7.134

• efficiency of the triple-channel microreactor. The product of this reaction is an allyl hydroperoxide alcohol that is used in the synthesis of artemisinin-derived antimalarial 1,2,4-trioxanes [48]. The reaction in the triple-channel and in batch was carried out as aforementioned with methylene blue as

Novel tetracyclic structures from the synthesis of thiolactone-isatin hybrids

• Renate Hazel Hans,
• Hong Su and
• Kelly Chibale

Beilstein J. Org. Chem. 2010, 6, No. 78, doi:10.3762/bjoc.6.78

• this project are the structure-activity relationships delineated from O-4 modified analogues which reportedly display enhanced antimalarial and promising antitubercular activity [15][16]. The other component of the envisaged hybrid, isatin (2) is an intriguing and synthetically versatile scaffold

Synthesis of spiroannulated and 3-arylated 1,2,4-trioxanes from mesitylol and methyl 4-hydroxytiglate by photooxygenation and peroxyacetalization

• Axel G. Griesbeck,
• Lars-Oliver Höinck and
• Jörg M. Neudörfl

Beilstein J. Org. Chem. 2010, 6, No. 61, doi:10.3762/bjoc.6.61

• pharmacological properties. Hydrophilic as well as lipophilic derivatives have been prepared from artemisinin and show improved antimalarial properties and better bioavailabilities [1][2][3][4][5]. In recent years, additional medicinal properties of artemisinin and the water soluble artesunates have been

• singlet oxygen ene reaction of allylic alcohols as a route to ß-hydroperoxy alcohols that can be transformed into 1,2,4-trioxanes by reaction with carbonyl compounds in the presence of Lewis acids [11]. This approach leads to simple cyclic peroxides (e.g. 2) which in some cases show similar antimalarial

• effects as the natural compound (Figure 1) [12]. An apparently useful structural feature is a large 3,3-spirofused hydrophobic group. The adamantane skeleton is a unique motif in other cyclic peroxides with antimalarial activities [13][14] which additionally exhibit other remarkable pharmaceutical

Synthesis of some novel annulated pyrido[2,3-d]pyrimidines via stereoselective intramolecular hetero Diels–Alder reactions of 1-oxa-1,3-butadienes

• Mohit L. Deb and
• Pulak J. Bhuyan

Beilstein J. Org. Chem. 2010, 6, No. 11, doi:10.3762/bjoc.6.11

• ], antihypertensive [13], bronchiodilator [15] and vasodilator [16] properties. Additionally, some compounds of this type exhibit antialergic [17], antimalarial [18], analgesic [19][20] and antifungal [21] activity. Consequently, much effort has been directed towards the synthetic manipulation of uracil for the