Synthesis of heteroglycoclusters by using orthogonal chemoselective ligations

• Baptiste Thomas,
• Michele Fiore,
• Isabelle Bossu,
• Pascal Dumy and
• Olivier Renaudet

Beilstein J. Org. Chem. 2012, 8, 421–427, doi:10.3762/bjoc.8.47

• with proteins through distinct binding sites, which may influence both affinity and selectivity [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. In this context, we previously reported a combinatorial procedure to prepare libraries of heteroglycoclusters displaying sugars and/or amino

• . Although it is easy to handle, this combinatorial procedure leads to the formation of inseparable mixtures of regioisomers, which precludes their utilization for further assays with relevant biological targets. In order to circumvent this drawback, we herein report the synthesis of similar

• heteroglycoclusters. Conclusion In this paper we have described an expedient and controlled assembly protocol to prepare heteroglycoclusters similar to those obtained previously from randomized combinatorial libraries [26]. Following two orthogonal chemoselective reactions, cyclopeptides 4 and 7 were successively

Binding of group 15 and group 16 oxides by a concave host containing an isophthalamide unit

• Jens Eckelmann,
• Vittorio Saggiomo,
• Svenja Fischmann and
• Ulrich Lüning

Beilstein J. Org. Chem. 2012, 8, 11–17, doi:10.3762/bjoc.8.2

• chloride transport experiments, and the EU for its support through the Marie Curie Research Training Network MRTN-CT-2006-035614 Dynamic Combinatorial Chemistry (DCC).

A straightforward approach towards combined α-amino and α-hydroxy acids based on Passerini reactions

• Ameer F. Zahoor,
• Sarah Thies and
• Uli Kazmaier

Beilstein J. Org. Chem. 2011, 7, 1299–1303, doi:10.3762/bjoc.7.151

• reactions together have made the IMCR highly popular in combinatorial chemistry [7][8]. Our group has been involved in amino acid and peptide synthesis for nearly two decades [12][13], and multicomponent reactions are known to play a dominant role [14][15]. In particular, the Ugi reaction has so far been

The Eschenmoser coupling reaction under continuous-flow conditions

• Sukhdeep Singh,
• J. Michael Köhler,
• Andreas Schober and
• G. Alexander Groß

Beilstein J. Org. Chem. 2011, 7, 1164–1172, doi:10.3762/bjoc.7.135

• blocks as shown in Scheme 1. Due to the ease of accessibility of the building blocks and the usually high-yielding S-alkylation step, the Eschenmoser coupling is an interesting reaction for diversity-oriented combinatorial synthesis [15][16][17]. The new carbon–carbon bond formation occurs during the

Chemistry in flow systems II

• Andreas Kirschning

Beilstein J. Org. Chem. 2011, 7, 1046–1047, doi:10.3762/bjoc.7.119

• technology that will probably never move beyond the status of a trend or a fashion? Have we not already seen this kind of fashionable topic initially promise so much and subsequently not quite meet expectations? For example the impact of “combinatorial chemistry” has turned out to be important, but the field

Multicomponent reactions

• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 960–961, doi:10.3762/bjoc.7.107

• Passerini reaction and the conclusions he drew from this. Now the major conceptual challenge comprises the engineering of novel types of MCR. Most advantageously and practically, MCR can often be extended into combinatorial, solid phase or flow syntheses promising manifold opportunities for developing novel

First synthesis of 2-(benzofuran-2-yl)-6,7-methylene dioxyquinoline-3-carboxylic acid derivatives

• Wentao Gao,
• Jia Liu,
• Yun Jiang and
• Yang Li

Beilstein J. Org. Chem. 2011, 7, 210–217, doi:10.3762/bjoc.7.28

• against human cancer cell lines, the methylenedioxy-bearing 2-PQ was identified as the most active compound in vivo [25]. In light of these findings and in view of structural diversity which plays a prominent role in medicinal and combinatorial chemistry and which leads to a faster and more efficient lead

Approaches towards the synthesis of 5-aminopyrazoles

• Ranjana Aggarwal,
• Vinod Kumar,
• Rajiv Kumar and
• Shiv P. Singh

Beilstein J. Org. Chem. 2011, 7, 179–197, doi:10.3762/bjoc.7.25

• aminopyrazoles 23 were hydrolysed to yield 24 in excellent yields. The synthesis is versatile and affords compoundswith a known pharmacophoric template ideally suited for combinatorial library generation. Another solid phase synthesis of 5-aminopyrazoles has been reported [39] by utilizing enamine nitrile 25 as

• -aminopyrazoles 28. This new 5-aminopyrazole synthesis is more versatile and efficient than its predecessor as it avoids the use of troublesome β-ketonitrile functionality. This new route is also ideally suited for the synthesis of combinatorial libraries for drug target screening. In 2009, an efficient three

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

Synthesis of 3-(quinolin-2-yl)- and 3,6-bis(quinolin-2-yl)-9H-carbazoles

• Yang Li and
• Wentao Gao

Beilstein J. Org. Chem. 2010, 6, 966–972, doi:10.3762/bjoc.6.108

• )carbazoles under solvent-free conditions by the reaction of β-nitrovinylcarbazole or bis(β-nitrovinyl)carbazole with salicylaldehydes. In light of these findings, and in view of the prominent role structural diversity plays in medicinal and combinatorial chemistry, we felt that there was a real need for the

(Pseudo)amide-linked oligosaccharide mimetics: molecular recognition and supramolecular properties

• José L. Jiménez Blanco,
• Fernando Ortega-Caballero,
• Carmen Ortiz Mellet and
• José M. García Fernández

Beilstein J. Org. Chem. 2010, 6, No. 20, doi:10.3762/bjoc.6.20

• -control of glycosidic linkages can be circumvented by their replacement by an amide function. Furthermore, as a result of the presence of amine and acid moieties, SAAs are suitable for conventional combinatorial synthesis in both solid and solution phase. Many of these aspects have been extensively

• number of functional groups that can be employed as surrogates for the natural amide and phosphodiester linkages, the thiourea functionality ranks among the most popular. Firstly, it can generally be generated in high yield and are ideally suited for solid phase and combinatorial approaches. Secondly

Acid- mediated reactions under microfluidic conditions: A new strategy for practical synthesis of biofunctional natural products

• Katsunori Tanaka and
• Koichi Fukase

Beilstein J. Org. Chem. 2009, 5, No. 40, doi:10.3762/bjoc.5.40

• 5 in dichloromethane at very low temperature of −78 to −90 °C. Rapid screening of more than 30 conditions in a combinatorial fashion led to a new reaction system where the microfluidic system is integrated with a conventional batch apparatus (Figure 2) [31]. Namely, the reaction solution resulting

• temperature control, and the easy handling of the reactive intermediate by controlling the residence time. As can be seen from the three examples cited in this review, rapid determination of the reaction conditions is another aspect of using the microfluidic conditions in a combinatorial fashion. The

Mitomycins syntheses: a recent update

• Jean-Christophe Andrez

Beilstein J. Org. Chem. 2009, 5, No. 33, doi:10.3762/bjoc.5.33

Zeolite catalyzed solvent- free one-pot synthesis of dihydropyrimidin- 2(1H)-ones – A practical synthesis of monastrol

• Mukund G. Kulkarni,
• Sanjay W. Chavhan,
• Mahadev P. Shinde,
• Dnyaneshwar D. Gaikwad,
• Ajit S. Borhade,
• Attrimuni P. Dhondge,
• Yunnus B. Shaikh,
• Vijay B. Ningdale,
• Mayur P. Desai and
• Deekshaputra R. Birhade

Beilstein J. Org. Chem. 2009, 5, No. 4, doi:10.3762/bjoc.5.4

• ) have recently gained tremendous importance in organic and medicinal chemistry. The main contributing factors are the high atom economy, wide application in combinatorial chemistry and diversity-oriented synthesis [4][5][6][7][8][9][10]. In general, the dihydropyrimidones (DHPMs) are known for their

Recent progress on the total synthesis of acetogenins from Annonaceae

• Nianguang Li,
• Zhihao Shi,
• Yuping Tang,
• Jianwei Chen and
• Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

• was based on the combinatorial coupling of two series of diastereomeric fragments 275 and 276, to produce intermediate 277, enjoyed the advantages of both efficiency and versatility. The third approach, which was based on partially functionalized intermediates, such as 278, combined the advantages of

Dimerization of propargyl and homopropargyl 6-azido- 6-deoxy- glycosides upon 1,3-dipolar cycloaddition

• Nikolas Pietrzik,
• Daniel Schmollinger and
• Thomas Ziegler

Beilstein J. Org. Chem. 2008, 4, No. 30, doi:10.3762/bjoc.4.30

• -butynyl 2,3,4-tri-O-acetyl-6-azido-6-deoxy-glycopyranosides in the D-gluco, D-galacto and D-manno series afford the corresponding dimeric cycloaddition products. Keywords: click reaction; cyclodimerization; glycosides; triazoles; Introduction Our ongoing interest in constructing combinatorial libraries

• variable spacers (Figure 1). Previously, we have prepared a series of glycosylated asparaginic acid building blocks containing as spacers either simple alkyl chains [1], or amino alcohols [2][3]. Such building blocks have been shown to be well suited for combinatorial solid phase or spot synthesis of

• glycosylated building blocks for the combinatorial synthesis of glycopeptides. Synthesis and reaction of compounds 4a and 4a'. Preparation of compounds 4a–g. Dimerization of Glycosides 4a–g under Cu-Catalysis. Supporting Information Supporting Information File 76: Experimental Data Acknowledgements This work

Aroylketene dithioacetal chemistry: facile synthesis of 4-aroyl- 3-methylsulfanyl- 2-tosylpyrroles from aroylketene dithioacetals and TosMIC

• H. Surya Prakash Rao and
• S. Sivakumar

Beilstein J. Org. Chem. 2007, 3, No. 31, doi:10.1186/1860-5397-3-31

• electrophilic centers to furnish cyclic compounds. We have recently synthesized a combinatorial library of 3-aroylcoumarins by the reaction of 2-hydroxyarylaldehydes and the AKDTAs in presence of a catalytic amount of piperidine in THF. [4] Notwithstanding the popularity of AKDTAs in the synthesis of

Microwave assisted synthesis of triazoloquinazolinones and benzimidazoquinazolinones

• Aboul-Fetouh E. Mourad,
• Ashraf A. Aly,
• Hassan H. Farag and
• Eman A. Beshr

Beilstein J. Org. Chem. 2007, 3, No. 11, doi:10.1186/1860-5397-3-11

• triazoloquinazolinones and benzimidazoquinazolinones. The reaction involves a three component condensation (with potential for combinatorial work) being carried out with almost productive yields by microwave irradiation and considerably shortened reaction time. Background Condensed heterocyclic systems with a partially

• triazoloquinazolinones and benzimidazoquinazolinones. The reaction involves a three component condensation (with potential for combinatorial work) being carried out with almost productive yields by microwave irradiation and considerably shortened reaction time (This conclusion was suggested by the referee.). Synthesis

Mixtures of monodentate P-ligands as a means to control the diastereoselectivity in Rh-catalyzed hydrogenation of chiral alkenes

• Manfred T. Reetz and
• Hongchao Guo

Beilstein J. Org. Chem. 2005, 1, No. 3, doi:10.1186/1860-5397-1-3

• Manfred T. Reetz Hongchao Guo Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim/Ruhr, Germany 10.1186/1860-5397-1-3 Abstract The previously reported concept of using mixtures of monodentate ligands in a combinatorial manner in order to influence enantio- or

• was found that appropriate 1:1 mixtures of two different P-ligands enhance the degree of diastereoselectivity relative to the use of the respective pure ligands themselves. Here, as in the previous cases regarding enantio- or regioselectivity, this type of combinatorial catalysis leads to improved

• catalytic profiles without the need to prepare new ligands. The application of combinatorial chemical methods in asymmetric catalysis has emerged as a promising area of research, and indeed several reviews covering the subject have appeared.[1][2][3][4][5][6][7][8] It is based on the preparation of