TMSBr-mediated solvent- and work-up-free synthesis of α-2-deoxyglycosides from glycals

• Mei-Yuan Hsu,
• Yi-Pei Liu,
• Sarah Lam,
• Su-Ching Lin and
• Cheng-Chung Wang

Beilstein J. Org. Chem. 2016, 12, 1758–1764, doi:10.3762/bjoc.12.164

• ); Introduction Deoxyglycosides are essential moieties of numerous bioactive natural products, and are prevalent subunits in antitumor and antibiotic agents [1][2][3]. Furthermore, 2-deoxy- and 2,6-dideoxyglycosides are crucial components for the pharmacology and bioactivity of many biologically active compounds

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• ][109][110][111][112][113]. Organic peroxides are widely used as oxidants in oxidative coupling processes [114][115][116][117][118][119][120]. Industrial-scale production of readily available and efficient initiators of free radical polymerization and effective biologically active compounds promotes the

• [280][281][282] as the catalyst. The obtained asymmetric oxidation products can be used in the multistep synthesis of new biologically active compounds. Possible mechanisms for the asymmetric oxidation of 3-substituted cyclobutanone 96a with H2O2 catalyzed by chiral phosphoric acid are presented in

• –d is proposed to occur through intermediate peroxy ester 150 (Scheme 43). 1,2-Dioxolanes and related cyclic systems have attracted considerable attention from synthetic chemists as they may be used for the preparation of biologically active compounds. Under acidic conditions, 3-hydroxy-1,2

Total synthesis of leopolic acid A, a natural 2,3-pyrrolidinedione with antimicrobial activity

• Atul A. Dhavan,
• Rahul D. Kaduskar,
• Loana Musso,
• Leonardo Scaglioni,
• Piera Anna Martino and
• Sabrina Dallavalle

Beilstein J. Org. Chem. 2016, 12, 1624–1628, doi:10.3762/bjoc.12.159

• -pyrrrolidinedione nucleus are indeed very few [4][5][6]. Even though this core can be considered an attractive target, synthetic studies directed to find new biologically active compounds are scarce as well [7][8][9]. The unique structure and bioactivity of leopolic acid prompted us to plan a synthesis which might

Catalytic Chan–Lam coupling using a ‘tube-in-tube’ reactor to deliver molecular oxygen as an oxidant

• Carl J. Mallia,
• Paul M. Burton,
• Alexander M. R. Smith,
• Gary C. Walter and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2016, 12, 1598–1607, doi:10.3762/bjoc.12.156

• ; oxygen; “tube-in-tube”; Introduction The functionalisation of aromatic and aliphatic amines has received considerable attention due to the number of biologically active compounds represented by these classes. For this reason different synthetic methods for C–N bond formation have been developed (Scheme

• active compounds [11][12]. In 2009 the groups of Stevens and van der Eycken reported on the Chan–Lam reaction as a continuous flow protocol using copper(II) acetate (1.0 equiv), pyridine (2.0 equiv) and triethylamine (1.0 equiv) in dichloromethane [13]. Generally, when using anilines or phenols as the

• with a large number of nucleophiles and tolerated a variety of substrates, making the process one of the most efficient ways for C–N/O coupling [11]. Several modifications of the Chan–Lam reaction have been reported, expanding its scope and it has since been used to synthesise several biologically

Enantioselective addition of diphenyl phosphonate to ketimines derived from isatins catalyzed by binaphthyl-modified organocatalysts

• Hee Seung Jang,
• Yubin Kim and
• Dae Young Kim

Beilstein J. Org. Chem. 2016, 12, 1551–1556, doi:10.3762/bjoc.12.149

• attention, and numerous catalytic enantioselective methods using chiral catalysts have been reported [9][10][11][12][13]. Oxindole and its derivatives can be exploited as important synthons to synthesize various alkaloid natural products and biologically active compounds [14][15][16]. In particular, 3,3

Development of chiral metal amides as highly reactive catalysts for asymmetric [3 + 2] cycloadditions

• Yasuhiro Yamashita,
• Susumu Yoshimoto,
• Mark J. Dutton and
• Shū Kobayashi

Beilstein J. Org. Chem. 2016, 12, 1447–1452, doi:10.3762/bjoc.12.140

• biologically active compounds are particularly important. Chiral Lewis acid/Brønsted base-catalyzed carbon–carbon bond-forming reactions are one of the most efficient methods from the viewpoint of atom economy because only proton transfer occurs between starting materials and target products [2]. Several kinds

Mutagenic activity of quaternary ammonium salt derivatives of carbohydrates

• Barbara Dmochowska,
• Karol Sikora,
• Anna Woziwodzka,
• Jacek Piosik and
• Beata Podgórska

Beilstein J. Org. Chem. 2016, 12, 1434–1439, doi:10.3762/bjoc.12.138

• [22][23][24]. To overcome many problems associated with QASs, they were combined with sugars. We intended to obtain biologically active compounds – especially antibacterial and antifungal – with high biocompatibility and good biodegradation properties. Some examples of fused molecules containing QASs

The aminoindanol core as a key scaffold in bifunctional organocatalysts

• Isaac G. Sonsona,
• Eugenia Marqués-López and
• Raquel P. Herrera

Beilstein J. Org. Chem. 2016, 12, 505–523, doi:10.3762/bjoc.12.50

• low temperature. This afforded the optically active 2-indolyl-1-nitro compounds 5 (up to 88% yield and up to 89% ee, Scheme 1). These products were found to be valuable synthetic precursors of biologically active compounds such as tryptamines [19][20] and 1,2,3,4-tetrahydro-β-carbolines [21]. In order

Natural products in synthesis and biosynthesis II

• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2016, 12, 413–414, doi:10.3762/bjoc.12.44

• the Beilstein Journal of Organic Chemistry on natural products in 2011 and 2013 [1][2], it is my pleasure to present the third issue on this topic. Natural products continue to be an inspiring field of research and an important source of potent biologically active compounds. This was recently

Asymmetric α-amination of β-keto esters using a guanidine–bisurea bifunctional organocatalyst

• Minami Odagi,
• Yoshiharu Yamamoto and
• Kazuo Nagasawa

Beilstein J. Org. Chem. 2016, 12, 198–203, doi:10.3762/bjoc.12.22

• important synthetic route to optically active α-amino acid derivatives with chiral quaternary stereocenters [1][2]. Since an α-amino acid moiety is frequently found in biologically active compounds, considerable efforts have been made to achieve a stereoselective synthesis of this structure [3][4]. In

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

• , Postal Code 123, Muscat, Oman 10.3762/bjoc.11.253 Abstract Anthraquinone (AQ) derivatives play a prominent role in medicine and also in textile industry. Bromaminic acid (1-amino-4-bromoanthraquinone-2-sulfonic acid) is an important precursor for obtaining dyes as well as biologically active compounds

Cu(I)-catalyzed N,N’-diarylation of natural diamines and polyamines with aryl iodides

• Svetlana P. Panchenko,
• Alexei D. Averin,
• Maksim V. Anokhin,
• Olga A. Maloshitskaya and
• Irina P. Beletskaya

Beilstein J. Org. Chem. 2015, 11, 2297–2305, doi:10.3762/bjoc.11.250

• polyamines like putrescine (butane-1,4-diamine), spermidine (N1-(3-aminopropyl)butane-1,4-diamine) and spermine (N1,N1'-(butane-1,4-diyl)dipropane-1,3-diamine) are biologically active compounds which play crucial roles in the processes of cell proliferation, apoptosis and adaptation to stress impacts. The

Synthesis of constrained analogues of tryptophan

• Elisabetta Rossi,
• Valentina Pirovano,
• Marco Negrato,
• Giorgio Abbiati and
• Monica Dell’Acqua

Beilstein J. Org. Chem. 2015, 11, 1997–2006, doi:10.3762/bjoc.11.216

• of these compounds. In particular, the dependence upon the substitution pattern at nitrogen and at the outer-ring double bond, highlighted the need to select the appropriate promoter for each desired transformation. Examples of drugs embodying unnatural amino acids. Examples of biologically active

• compounds embodying constrained analogues of tryptophan. Structure elucidation of diastereoisomeric tetrahydrocarbazoles 3a and 3’a via NMR experiments. Planned Diels–Alder reactions for the synthesis of tetrahydrocarbazoles as constrained analogues of tryptophan. Synthesis of unprotected tryptophan

The facile construction of the phthalazin-1(2H)-one scaffold via copper-mediated C–H(sp²)/C–H(sp) coupling under mild conditions

• Wei Zhu,
• Bao Wang,
• Shengbin Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2015, 11, 1624–1631, doi:10.3762/bjoc.11.177

• phthalazin-1(2H)-one scaffold represents an important class of privileged structures and has been widely found in numerous biologically active compounds and drug molecules [1][2][3][4][5][6]. For example (Figure 1), azelastine is a selective histamine antagonist, which is recommended for the treatment of

Reactions of nitroxides 15. Cinnamates bearing a nitroxyl moiety synthesized using a Mizoroki–Heck cross-coupling reaction

• Jerzy Zakrzewski and
• Bogumiła Huras

Beilstein J. Org. Chem. 2015, 11, 1155–1162, doi:10.3762/bjoc.11.130

• -oxyl; cinnamates; Mizoroki–Heck cross-coupling reaction; nitroxides; Introduction Cinnamic acid derivatives are known as biologically active compounds. Cinnamic acid and its hydroxy derivatives bearing a phenolic moiety such as coumaric, caffeic, ferulic, sinapinic, and chlorogenic acids [2][3][4][5

Synthesis of 1,2-cis-2-C-branched aryl-C-glucosides via desulfurization of carbohydrate based hemithioacetals

• Henok H. Kinfe,
• Fanuel M. Mebrahtu,
• Mandlenkosi M. Manana,
• Kagiso Madumo and
• Mokela S. Sokamisa

Beilstein J. Org. Chem. 2015, 11, 583–588, doi:10.3762/bjoc.11.64

• substituents of the sugar moiety are locked in a 1,2-cis configuration in the thiochroman ring [16][17]. With our long standing on the chemical transformation of the thiochromans into important intermediates and biologically active compounds [16][17][18][19], it was noted that hemithioacetal 3 can be readily

• light into the understanding of the mechanism of desulfurization using Raney nickel. The use of these 2-C-branched 1,2-cis-aryl-C-glucosides, having the required orientation at the anomeric and C-2 positions, in the synthesis of compounds that will mimic biologically active compounds that are substrates

First chemoenzymatic stereodivergent synthesis of both enantiomers of promethazine and ethopropazine

• Paweł Borowiecki,
• Daniel Paprocki and
• Maciej Dranka

Beilstein J. Org. Chem. 2014, 10, 3038–3055, doi:10.3762/bjoc.10.322

• columns. Keywords: ethopropazine; lipase-catalyzed kinetic resolution; Mosher methodology; promethazine; stereodivergent synthesis; Introduction Since enantiomorphs of biologically active compounds exhibit significant differences in their pharmacokinetic and pharmacodynamic behavior, optical purity of

A one-pot multistep cyclization yielding thiadiazoloimidazole derivatives

• Debabrata Samanta,
• Anup Rana,
• Jan W. Bats and
• Michael Schmittel

Beilstein J. Org. Chem. 2014, 10, 2989–2996, doi:10.3762/bjoc.10.317

• carbodiimide and thiourea units under in situ conditions. The product structure was confirmed by single crystal X-ray analysis in the solid state. The substitution pattern (aryl, benzyl, sec-alkyl) may be varied easily to achieve potentially biologically active compounds with interesting properties. The free

Come-back of phenanthridine and phenanthridinium derivatives in the 21st century

• Lidija-Marija Tumir,
• Marijana Radić Stojković and
• Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2930–2954, doi:10.3762/bjoc.10.312

• derivatives are one of the most intensively studied families of biologically active compounds with efficient DNA binding capability. Attracting attention since DNA structure discovery (1960s), they were early recognized as a symbol of DNA intercalative binding, for many decades applied as gold-standard DNA

Recent advances in the electrochemical construction of heterocycles

• Robert Francke

Beilstein J. Org. Chem. 2014, 10, 2858–2873, doi:10.3762/bjoc.10.303

• . The large interest in this field is attributable to the occurrence of heterocyclic units in numerous natural products and biologically active compounds such as hormones, antibiotics and vitamins [1]. Considering the fact that more than 70% of all active ingredients in pharmaceutical and agrochemical

• results. In view of the fact that the indole unit is present in a variety of natural products and biologically active compounds, Arcadi, Rossi et al. reported a clean and mild electrochemical method for the construction of this heterocycle (Scheme 17) [62]. The procedure is initiated with the electrolysis

Thermal and oxidative stability of the Ocimum basilicum L. essential oil/β-cyclodextrin supramolecular system

• Daniel I. Hădărugă,
• Nicoleta G. Hădărugă,
• Corina I. Costescu,
• Ioan David and
• Alexandra T. Gruia

Beilstein J. Org. Chem. 2014, 10, 2809–2820, doi:10.3762/bjoc.10.298

• the corresponding biologically active compounds. These were used as raw mixtures (e.g., extracts for food supplements), as well as purified bioactive compounds for the treatment of various diseases. They were used in natural form or after derivatization to a more bioactive compound, such as the

Derivatives of the triaminoguanidinium ion, 3. Multiple N-functionalization of the triaminoguanidinium ion with isocyanates and isothiocyanates

• Jan Szabo,
• Kerstin Karger,
• Nicolas Bucher and
• Gerhard Maas

Beilstein J. Org. Chem. 2014, 10, 2255–2262, doi:10.3762/bjoc.10.234

• . Molecular architectures of this kind could be useful under several aspects, for example in biologically active compounds, as novel ligands in metal complexes, for the construction of dendrimers, and in crystal engineering. Along these lines, several 1,2,3-tris(iminyl)guanidines have been prepared from

Palladium-catalysed cyclisation of alkenols: Synthesis of oxaheterocycles as core intermediates of natural compounds

• Miroslav Palík,
• Jozef Kožíšek,
• Peter Koóš and
• Tibor Gracza

Beilstein J. Org. Chem. 2014, 10, 2077–2086, doi:10.3762/bjoc.10.216

• sizes are found in many different biologically active compounds. Particularly, substituted tetrahydrofuran units are present in a large branch of natural products that display interesting biological properties, such as goniofufurone 1 [1], goniothalesdiol 2 [2], varitriol 3 [3], erythroskyrine 4 [4][5

Synthesis of 2-substituted tryptophans via a C3- to C2-alkyl migration

• Michele Mari,
• Simone Lucarini,
• Francesca Bartoccini,
• Giovanni Piersanti and
• Gilberto Spadoni

Beilstein J. Org. Chem. 2014, 10, 1991–1998, doi:10.3762/bjoc.10.207

• alkylation; indoles; migration; tryptophans; Introduction Facile access to tryptophan and unnatural tryptophan derivatives is of general interest because tryptophans are found in many naturally occurring compounds and are an important component of biologically active compounds [1][2][3][4][5][6][7

Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

• Thilo Focken and
• Stephen Hanessian

Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195

• and complex natural products and also of biologically active compounds. The phosphonamide anions are derived from a small number of common motifs as shown in Figure 1. Diazaphospholidine 2 was introduced by Hanessian and co-workers, and represents the most commonly used phosphonamide in organic

• on the application of phosphonamide reagents in the total synthesis of natural products and biologically active compounds. An overview of the molecules synthesized by phosphonamide technology is shown in Figure 2. Each molecule shown will be discussed in detail later in this review. First, relevant