Design of a novel tryptophan-rich membrane-active antimicrobial peptide from the membrane-proximal region of the HIV glycoprotein, gp41

• Evan F. Haney,
• Leonard T. Nguyen,
• David J. Schibli and
• Hans J. Vogel

Beilstein J. Org. Chem. 2012, 8, 1172–1184, doi:10.3762/bjoc.8.130

• , we attempted to design a novel AMP using a helical peptide scaffold known to interact at the surface of phospholipid bilayers. Using this template, a series of derivatives were synthesized to augment many of the important antimicrobial factors, with the goal of generating a novel peptide sequence

The use of glycoinformatics in glycochemistry

• Thomas Lütteke

Beilstein J. Org. Chem. 2012, 8, 915–929, doi:10.3762/bjoc.8.104

• their biosynthesis: DNA, RNA and proteins are synthesized by copying, transcription or translation, respectively, of nucleic acids, whereas carbohydrates are built in a non-template-driven approach by the sequential action of various glycosyltransferases (GT) that add monosaccharides to an existing

Multistep organic synthesis of modular photosystems

• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2012, 8, 897–904, doi:10.3762/bjoc.8.102

• central naphthalenediimide (NDI) [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] to act as a template for the central stack and two peripheral NDIs to act as templates for stack exchange. They are embedded into hydrogen-bonded networks, to assure self-organization, and four geminal

• and alkylation with ethyl bromoacetate (10) gave ethyl ester 11, and final ester hydrolysis lead to the desired acid 7. The peripheral NDIs 12, designed to template for stack exchange on initiator 2, were prepared from naphthalenedianhydride (NDA) 13. Microwave-assisted imidation [15] with the two

• NDI 18 of initiator 2, designed to initiate and template for SOSIP, was accessible from NDA 13 as well. The synthesis of NDI 19 by microwave-assisted imidation with Boc-protected lysine 20 has been reported before in the literature [15]. Reaction with Cbz-hydrazine gave the Cbz-protected NDI hydrazide

Catalyst-free and solvent-free Michael addition of 1,3-dicarbonyl compounds to nitroalkenes by a grinding method

• Zong-Bo Xie,
• Na Wang,
• Ming-Yu Wu,
• Ting He,
• Zhang-Gao Le and
• Xiao-Qi Yu

Beilstein J. Org. Chem. 2012, 8, 534–538, doi:10.3762/bjoc.8.61

• optimal molar ratio. Having established the optimum conditions, the template reaction was enlarged to a gram scale, and a similar result was obtained (data not shown). To test the generality of this grinding Michael addition with respect to reactants, different aromatic and heteroaromatic nitroalkenes

Fifty years of oxacalix[3]arenes: A review

• Kevin Cottet,
• Paula M. Marcos and
• Peter J. Cragg

Beilstein J. Org. Chem. 2012, 8, 201–226, doi:10.3762/bjoc.8.22

• found to be necessary to remove the ethanol stabilizer and to aid deprotection. Yields were up to 50%, and, interestingly, there was no template effect from any alkali metals. An analogous strategy was developed by Georghiou in 2001 to prepare asymmetric oxacalix[3]naphthalene derivatives [20], and this

• , derivatives containing carbonyl groups (ester, acid, amide and ketone) and heteroatoms, such as nitrogen and phosphorous, have been obtained. In 1993, Shinkai et al. [29] reported the synthesis of the first ethyl ester derivative 12a. In the belief that the alkali-metal template effect would lead

• suggests a template effect for both K+ and Cs+ that occurs whether an amide or ester is formed, and a function for Na+ beyond that of a mere template. One consequence of this work is that the preferred route to C3 symmetric cone derivatives is through tris(amide) derivative 17a, which can readily be

Improved syntheses of high hole mobility phthalocyanines: A case of steric assistance in the cyclo-oligomerisation of phthalonitriles

• Daniel J. Tate,
• Rémi Anémian,
• Richard J. Bushby,
• Suwat Nanan,
• Stuart L. Warriner and
• and Benjamin J. Whitaker

Beilstein J. Org. Chem. 2012, 8, 120–128, doi:10.3762/bjoc.8.14

• phthalocyanines, thus leading to substantially enhanced yields. Just as the cyclo-oligomerisation reaction is favoured by the “pull” of a transition metal template, it can also be enhanced using the “push” of suitable α-substituents. This makes the metal-free phthalocyanines much easier to produce on a multigram

• , for some of the branched-chain α-alkylated systems, we obtained very good yields even without using a metal template. As shown in Table 1, not only are some of these yields exceptionally high (for nontemplated phthalonitrile oligomerisation), but there is also a clear relationship between the isolated

(How) does 1,3,5-triethylbenzene scaffolding work? Analyzing the abilities of 1,3,5-triethylbenzene- and 1,3,5-trimethylbenzene-based scaffolds to preorganize the binding elements of supramolecular hosts and to improve binding of targets

• Xing Wang and
• Fraser Hof

Beilstein J. Org. Chem. 2012, 8, 1–10, doi:10.3762/bjoc.8.1

• 1,3,5-triethylbenzene template directs the binding elements toward the same face of the central ring, hence increasing the binding affinity. At the same time the 1,3,5-trimethylbenzene scaffold, without steric-gearing effects, has also been found to improve the binding affinities of hosts compared to

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

• 15d) were also found to exhibit weak antiplasmodial activity. On the other hand, the aminopropane unit has again proven its value as a template for the preparation of novel antimalarial agents, as a variety of structurally different aminopropanes were demonstrated to exhibit weak to moderate

Supramolecular chemistry II

• Christoph A. Schalley

Beilstein J. Org. Chem. 2011, 7, 1541–1542, doi:10.3762/bjoc.7.181

• Beilstein Journal of Organic Chemistry [1]. This first series of articles had quite a broad scope ranging from encapsulation and carbohydrate, peptide, anion and ammonium ion binding, through chiral recognition, the formation of pseudorotaxanes and template effects, all the way to allosteric binding to

Gold-catalyzed heterocyclizations in alkynyl- and allenyl-β-lactams

• Benito Alcaide and
• Pedro Almendros

Beilstein J. Org. Chem. 2011, 7, 622–630, doi:10.3762/bjoc.7.73

• activation [17][18][19][20][21][22][23], the use of 2-azetidinones as chiral building blocks in organic synthesis is now well established [24][25][26][27][28]. Moreover, the cyclic 2-azetidinone skeleton has been extensively used as a template on which to build carbo(hetero)cyclic structures joined to the

C–C (alkynylation) vs C–O (ether) bond formation under Pd/C–Cu catalysis: synthesis and pharmacological evaluation of 4-alkynylthieno[2,3-d]pyrimidines

• Dhilli Rao Gorja,
• K. Shiva Kumar,
• K. Mukkanti and
• Manojit Pal

Beilstein J. Org. Chem. 2011, 7, 338–345, doi:10.3762/bjoc.7.44

• that 4-alkynylthieno[2,3-d]pyrimidine can be used as a template for the identification of novel and potential anticancer agents. Conclusion In conclusion, the present study demonstrates the first efficient synthesis 4-alkynylthieno[2,3-d]pyrimidines in good to excellent yields. The combination of Pd/C

Anion–π interactions influence pK_a values

• Christopher J. Cadman and
• Anna K. Croft

Beilstein J. Org. Chem. 2011, 7, 320–328, doi:10.3762/bjoc.7.42

• -structure mining [5][6][7], there has been a resurgence of work in this area. One prime focus has been on anion–π interactions as a means to design selective supramolecular anion receptors and template-directed synthesis of macrocyclic complexes has also been achieved [8][9][10][11][12][13][14][15][16][17

Reciprocal polyhedra and the Euler relationship: cage hydrocarbons, C_nH_n and closo-boranes [B_xH_x]²⁻

• Michael J. McGlinchey and
• Henning Hopf

Beilstein J. Org. Chem. 2011, 7, 222–233, doi:10.3762/bjoc.7.30

• two triquinacene units could be coupled (Scheme 8). The requisite C10H10 moiety, 44, has been prepared (most elegantly via Paquette’s domino Diels–Alder route [26]) but all attempts at controlled dimerization (even on a transition metal template [27]) have so far proven fruitless. A second approach is

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

• represents an important heterocyclic template that has attracted considerable interest because of its long history of application in the pharmaceutical and agrochemical industries [1][2][3][4]. These compounds have been extensively investigated over the past one hundred years and their chemistry has been

• 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

Highly substituted benzannulated cyclooctanol derivatives by samarium diiodide-induced cyclizations

• Jakub Saadi,
• Irene Brüdgam and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2010, 6, 1229–1245, doi:10.3762/bjoc.6.141

• cyclization. Since samarium(III) is very oxophilic, it is possible that the samariumoxy group coordinates tert-butanol, which is then a more acidic proton source (intermediates B and C, Scheme 6). This template effect would then be responsible for the stereoselective protonation governed by the samariumoxy

(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

• and co-workers undertook the synthesis of carbopeptoids based on the oxetane template (Figure 7) [46][47][48]. Conformational analysis was carried out for two oxetane β-SAA hexamers with the 6-deoxy-L-altro and D-arabino configurations by means of detailed NMR and IR studies in combination with

• telomer replacement in cancer cells is by inhibiting the telomerase enzyme by blocking the telomeric RNA 11-base template (5′-CUAACCCAAC-3′). For this purpose, Bruice and co-workers [107] prepared complementary DNG (5′-GATTGGGATTG-3′) to telomeric RNA complex. Binding studies demonstrated that the DNG

Templated versus non-templated synthesis of benzo-21-crown-7 and the influence of substituents on its complexing properties

• Wei Jiang and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2010, 6, No. 14, doi:10.3762/bjoc.6.14

• Wei Jiang Christoph A. Schalley Institut für Chemie und Biochemie, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany 10.3762/bjoc.6.14 Abstract Two procedures for the synthesis of benzo-21-crown-7 have been explored. The [1+1] macrocyclization with KBF4 as the template was found to be

• more efficient than the intramolecular macrocyclization without template. Pseudorotaxanes form with secondary ammonium ions bearing at least one alkyl chain narrow enough to slip into the crown ether. Substitution on benzo-21-crown-7 or on the secondary ammonium axle alters the binding affinity and

• binding mode. Compared to dibenzo-24-crown-8, the complexing properties of benzo-21-crown-7 turn out to be more susceptible to modifications at the crown periphery. Keywords: benzo-21-crown-7; pseudorotaxane; self-sorting; supramolecular chemistry; template; Introduction Mechanically interlocked

Synthesis of rigidified flavin–guanidinium ion conjugates and investigation of their photocatalytic properties

• Harald Schmaderer,
• Mouchumi Bhuyan and
• Burkhard König

Beilstein J. Org. Chem. 2009, 5, No. 26, doi:10.3762/bjoc.5.26

• activity was investigated in benzyl ester cleavage, nitroarene reduction and a Diels–Alder reaction. The modified flavins photocatalyze the reactions, but the introduced substrate binding site does not enhance their performance. Keywords: flavin; guanidine; Kemp’s acid; photocatalysis; template

The oxanorbornene approach to 3-hydroxy, 3,4-dihydroxy and 3,4,5-trihydroxy derivatives of 2-aminocyclohexanecarboxylic acid

• Ishmael B. Masesane,
• Andrei S. Batsanov,
• Judith A. K. Howard,
• Raju Mondal and
• Patrick G. Steel

Beilstein J. Org. Chem. 2006, 2, No. 9, doi:10.1186/1860-5397-2-9

• oxanorbornene adduct derived from the Diels-Alder reaction of ethyl (E)-3-nitroacrylate and furan provides a versatile template for the stereoselective synthesis of hydroxylated derivatives of 2-aminocyclohexanecarboxylic acid (ACHC). Introduction In recent years there has been a surge of interest in cyclic β

• describe the stereoselective synthesis of further novel hydroxylated derivatives of ACHC using the exo nitro oxanorbornene adduct as the template. The basis of our approach to these poly hydroxylated cyclohexane β-amino acids was the recognition that the bicyclic oxanorbornene cycloadduct, derived from the

• Diels-Alder reaction between furan and ethyl nitroacrylate, represented a versatile template that could be elaborated to the desired targets via a variety of complementary oxidative processes coupled with a base promoted ring fragmentation, Scheme 1. Results and Discussion Oxanorbornene Synthesis

One-pot synthesis of novel 1H-pyrimido[4,5-c][1,2]diazepines and pyrazolo[3,4-d]pyrimidines

• Dipak Prajapati,
• Partha P. Baruah,
• Baikuntha J. Gogoi and
• Jagir S. Sandhu

Beilstein J. Org. Chem. 2006, 2, No. 5, doi:10.1186/1860-5397-2-5

• minor tranquiliser, a large number of seven-membered heterocyclic compounds with the benzodiazepine moiety have been synthesized and tested for psychotropic properties.[29] This moiety has been found to represent a versatile template in peptidomimetic design and it is also found in several other