Themed collection Organic & Biomolecular Chemistry 10th Anniversary

Introducing the 10th anniversary issue of Organic & Biomolecular Chemistry.

The discovery of methylthioxylose and studies toward understanding its origins and biological roles.

Liquid ammonia is a useful solvent for many organic reactions including aliphatic and nucleophilic substitution reactions and has the potential to replace conventional dipolar aprotic solvents in a range of reactions.

This perspective article discusses developments of metal-free hydrogenation catalysts derived from “frustrated Lewis pair” (FLP) systems.

Recent advances in chemical and semisynthesis of proteins are becoming increasingly instrumental to prepare homogeneous posttranslationally modified proteins for biochemical and structural analyses. Here, we survey these efforts and their importance in dissecting the role of several posttranslational modifications on various proteins.

This perspective article highlights the recent developments of peptide and peptidomimetic ligands for CXC chemokine receptor 4 (CXCR4).

The radical addition of xanthates to alkenes provides a practical and flexible entry to a broad variety of heteroaromatic structures.

A new synthetic lectin features pyrroles and amines as polar binding units. In aqueous buffer, glucose is bound selectively over all other tested carbohydrates.

The synthesis, biological activity and pharmacokinetics of a stable cyclic conotoxin with two independent pharmacophores are described.

Pentapodal ω-functional derivatives of corannulene have been synthesized from sym-pentachlorocorannulene by iron-catalyzed aryl–alkyl cross coupling reactions.

A catalytic Mannich reaction of a simple ester with no activating functionality at the α-position via a product-base mechanism was reported.

Novel self-condensation of 3-(azol-5-yl)-1,1-dimethylenamines has been found to form new C–C bonds leading to 2,4-(1,2,3-triazole-1,2,3-thiadiazole-3-phenylisothiazole)-(1E,3Z)-5-yl-butadiene-1-amines.

Permeation of ammonia through Teflon AF-2400 (which is temperature and solvent dependent) facilitated the continuous flow Paal–Knorr synthesis of pyrroles.

The intramolecular Staudinger-aza-Wittig reaction was used for the first preparation of the DEF ring system of noelaquinone.

The design and synthesis of conformationally constrained amphiphilic benzoylurea α-helix mimetics is described.

In the endofungal bacterium Burkholderia rhizoxinica novel rhizoxin derivatives with unusual nitrile substitutions are formed by a rare photochemical transformation.

The mode of thioether macrocyclization of peptides containing an N-terminal 2-chloroacetyl group and two or three competing cysteine residues at downstream positions has been extensively studied, leading to a strategy for designated formation of overlapping-bicyclic peptides or dumbbell-type bicyclic peptides.

The synthesis of a series of o-sulfonamido-arylhydrazides and their activity as inhibitors of LL-diaminopimelic acid aminotransferase are described.

The ease with which dimesitylbisanthene oxidizes in air to the corresponding bay region quinone is seen as a warning that hydrogen-terminated carbon nanotubes having bay regions on their rims may be highly sensitive to air oxidation.

We report the first observation of direct molecular contacts between ThT and model peptide aggregates by applying solid-state NMR spectroscopy.

The bis-pyridinylidene 13 converts aliphatic and aryl triflate esters to the corresponding alcohols and phenols respectively, using DMF as solvent, generally in excellent yields.

The combined carbometalation–zinc homologation–allylation reaction with ketones allows the preparation of allylic vicinal diol derivatives possessing two adjacent quaternary centers in an acyclic system through the concomitant formation of three new carbon-carbon bonds in a single-pot operation..

The influence of the electrophilicity of aromatic nitriles on cysteine protease inhibition and cytotoxicity was investigated. Calculations were used to obtain nitrile electrophilicities, revealing a clear correlation with biological affinity.

A general approach to the asymmetric synthesis of spirodihydrocoumarins with a quaternary stereocenter was achieved through a favoured 21-membered supramolecular transition state using sequential Michael and lactonization reactions.

A selective method for the reduction of lactones of all ring sizes and topologies using SmI₂–H₂O and a Lewis base is described.

Enantioselective direct aldol reaction of α-substituted nitroacetates with aqueous formaldehyde has been achieved under base-free neutral phase-transfer conditions.

Squaraine rotaxanes with four large stopper groups attached to the ends of the encapsulated squaraine are excellent fluorescent tracers with rapid renal clearance and very low tissue uptake in living mice.

In this paper we present the synthesis of glyco-phosphoramidate conjugates as easily accessible analogs of glyco-phosphorous esters via the Staudinger-phosphite reaction.

The formation of H-phosphonate diesters is an important step in the synthesis of oligonucleotides.

Total chemical synthesis was used to site-specifically ¹³C-label active site Asp25 and Asp25′ residues in HIV-1 protease and in several chemically synthesized analogues of the enzyme molecule.

The self-assembly formation between the bis amidothiourea ligands 1 and 2 with Tb(III) is described. These give rise to Tb(III) centred emission which is affected upon binding of these to anions such as acetate and phosphate.

3′-endo-Sugar-locked 5′-acyl sulfamoyl adenosines inhibit Trypanosoma and Leishmania with IC₅₀s of 0.25–0.51 μM.

A new family of nonlinear fluorescent probes for specific DNA or protein labeling was designed by structure space exploration around the vinyl-triphenylamine core.

A facile access has been developed to highly functionalized polycyclic isoxazoles, suitable intermediates for the synthesis of semi-aromatized polyketides, via a two-step protocol including regioselective 1,3-dipolar cycloaddition and MnO₂-mediated dehydrogenation.

Fluorinated bipyridine discotics self-assemble into stable helical columnar mesophases and alternating helical assemblies with hydrocarbon bipyridine discotics in fluorinated media.

The 2,6-pyridylene-bridged chiral diporphyrin nanotweezers recognise handedness and diameter of SWNTs simultaneously and independently, yielding optically active SWNTs with narrow diameter range.

A highly efficient one-pot synthesis of valuable 3,4-substituted chromenone derivatives by the reaction of 1,3-diketones with aldehydes in the presence of L-proline was developed. Chiral 3-substituted chromenones are obtained with high enantioselectivities when a chiral diarylprolinol TMS-ether is applied in the reaction.

[2]Pseudorotaxanes, [2]rotaxanes and metal–organic rotaxane framework materials are prepared that utilise symmetrical DB24C8 analogues containing four CH₂OR (R = CH₂CH₂CH₃, CH₂(C₆H₅), C₆H₅ and C₆H₄(4-COOEt)) substituents on the 4 and 5 positions of the aromatic rings.

Effective molarities for intramolecular phosphonate diester-phenol H-bonds vary with solvent indicating that changes in the solvation shell can make a significant contribution to the stability of a supramolecular complex.

Two inhibitors with selectivity against V. cholerae sialidase and human cytosolic sialidase NEU2, respectively, were identified.

A bicyclo[3.2.0]hept-5-ene formed in good yield in a gold(I)-catalysed reaction, has been structurally characterised.

A simple method for on-resin synthesis of dipicolylamine (Dpa)-containing peptides was developed, which enables the design of a unique metal-responsive peptide.

Enethioate derivatives of prochiral 1,3-diones underwent desymmetrizing catalytic reductive aldol cyclizations to furnish β-hydroxythioesters with >98 : 2 dr, up to 94% yield and 98% ee.

The complexation behaviour of a new bis-porphyrin bearing a rotatable linker with diaza-ligands has been studied. Featuring a semi-flexible biphenyl linkage, these bis-porphyrin systems are capable of reversible binding to small ditopic molecules, opening up the possibility of developing a new generation of chemoswitchable systems.

A 3-deoxy-D-manno-octulosonic acid (KDO) building block was made starting from glucose through pathway engineering of Escherichia coli and subsequent chemical modifications to provide an alternative method to produce KDO, usually found in plant and bacterial oligosaccharides.

The first total synthesis of (+)-spirastrellolide A methyl ester was achieved based on the sequential coupling of four fragments and a remarkably high yielding macrolactonisation. A series of simplified analogues of spirastrellolide incorporating the C26–C47 region were also prepared by π-allyl Stille coupling reactions.

A modular strategy for the synthesis of the antimitotic marine macrolide spirastrellolide A methyl ester was adopted based on the envisaged sequential coupling of a series of four suitably functionalised fragments.

Dynamic amphiphiles with fluorescent naphthalenediimide tails can be used to label membrane microdomains and activate DNA as transporters in lipid bilayers.

In order to identify new leads for the treatment of type 2 diabetes, polyenic molecules A and B derived from nipecotic acid and dienol derivatives C have been prepared and their effect on PPARs transcriptional activity evaluated and compared to that of rosiglitazone, WY14,643 and GW501516.

Guest discrimination: NMR titration and ITC experiments were used to examine the binding behavior of differently disubstituted diamide guests to a tetralactam macrocycle.

Different wavelengths of light can be used to selectively quench the emission from upconverting nanoparticles depending on the isomeric state of photoswitches decorated onto their surfaces.

Absorption and fluorescence in solution/solid states. High fluorescence quantum yields. Assignment of UV-vis absorption. Explanation of unique HOMO–LUMO behaviour.

Collagen mimetic peptides bind tightly to mammalian collagen in vitro and ex vivo, providing a new modality for wound care.

Classical doubly diastereoselective “matching” and “mismatching” effects are not observed upon conjugate addition of the antipodes of lithium N-benzyl-(N-α-methylbenzyl)amide to tert-butyl (E)-4,5-O-isopropylidene-4,5-dihydroxyhex-2-enoates.

Biotransformation of 3- and 2,5-substituted phenols yielded enantiopure cyclohexenone cis-diols; ECD spectroscopy, X-ray crystallography and stereochemical correlation was used to establish absolute configurations.

Multi-component organic crystals containing different kinds of helical motifs were constructed based on bile acids and cinchona alkaloids.

Reactions of the allyltin trichlorides generated from (4S)-4-benzyloxypent-2-enyl(tributyl)stannane and analogous stannanes with imines prepared from glyoxalates proceed with useful levels of 1,5-stereocontrol; modest 1,6-stereocontrol was observed using 5-hydroxy- and 5-methoxy-hex-2-enylstannanes.

The combined use of the coinage metals copper and gold allows an efficient stereoselective synthesis of (+)-varitriol and various analogs.

Considering the synthesis of the caprazamycin core, the scope and limitations of platinum catalyzed 7-endo cyclization of internal alkynyl amides were disclosed.

The binding of thiamine pyrophosphate (TPP) to the thiM riboswitch has been systematically explored by testing a range of TPP analogues in which the aminopyrimidine ring, the central thiazolium ring, and the pyrophosphate tail are each replaced in turn by similar structures.

Novel potent antagonists of quorum sensing in Pseudomonas aeruginosa are reported, which strongly inhibit the production of virulence factors.

The methyl ether derivatives of a number of mulberry Diels–Alder adducts have been synthesized by a thermal [4 + 2]-cycloaddition reaction between a chalcone and dehydroprenyl diene. A H-bonded ortho OH substituent on the chalcone was found to be essential for Diels–Alder reactivity and the experimental results were supported by density functional theory calculations.

In this article we have intensively addressed the question how solvents effect the aggregation strength of perylene bisimides.

Iridium-catalyzed asymmetric allylic amination of allylic carbonates with 2-allylanilines and ring-closing-metathesis reaction provided highly enantioenriched 2,5-dihydrobenzo[b]azepine derivatives.

NMR and modelling give new insights on the molecular recognition of unnatural α-Gal-N-linked glycopeptides by lectins.

Peptides with an N-terminal nitrone and a C-terminal α-ketoacid undergo chemoselective cyclizations without reagents and in the presence of unprotected side chains. The precursors are prepared by Fmoc-SPPS.

Three double stranded polymeric ladderphanes with 16-π-electron antiaromatic metallocycle linkers are synthesised by ring opening metathesis polymerisation of the corresponding bisnorbornene monomers.

The union of the biologically privileged 6,6-spiroacetal scaffold with azides by the regioselective Copper-Catalysed Azide–Alkyne Cycloaddition (CuAAC) affords novel C-linked spiroacetal-triazoles. The anomeric C-linkage is anticipated to provide increased stability towards hydrolytic cleavage.

Tautomeric switching is observed in a series of benzimidazole-based anion receptors upon addition of basic anions.