Welcome to the 10th anniversary issue of Organic & Biomolecular Chemistry
Introducing the 10th anniversary issue of Organic & Biomolecular Chemistry.
Methylthioxylose – a jewel in the mycobacterial crown?
The discovery of methylthioxylose and studies toward understanding its origins and biological roles.
Organic reactivity in liquid ammonia
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.
“Frustrated Lewis pair” hydrogenations
This perspective article discusses developments of metal-free hydrogenation catalysts derived from “frustrated Lewis pair” (FLP) systems.
Chemical and semisynthesis of posttranslationally modified proteins
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.
Peptide and peptidomimetic ligands for CXC chemokine receptor 4 (CXCR4)
This perspective article highlights the recent developments of peptide and peptidomimetic ligands for CXC chemokine receptor 4 (CXCR4).
A unified access to diverse heteroaromatic scaffolds using the radical chemistry of xanthates
The radical addition of xanthates to alkenes provides a practical and flexible entry to a broad variety of heteroaromatic structures.
New H-bonding patterns in
biphenyl-based synthetic lectins; pyrrolediamine bridges enhance glucose-selectivity
A new synthetic lectin features pyrroles and amines as polar binding units. In aqueous buffer, glucose is bound selectively over all other tested carbohydrates.
Conotoxin engineering: dual pharmacophoric
noradrenaline transport inhibitor/integrin binding peptide with improved stability
The synthesis, biological activity and pharmacokinetics of a stable cyclic conotoxin with two independent pharmacophores are described.
Sym-(CH2X)5-corannulenes: molecular pentapods displaying functional group and bioconjugate appendages
Pentapodal ω-functional derivatives of corannulene have been synthesized from sym-pentachlorocorannulene by iron-catalyzed aryl–alkyl cross coupling reactions.
Development of strong Brønsted base catalysis: catalytic direct-type Mannich reactions of non-activated
esters via a product-base mechanism
A catalytic Mannich reaction of a simple ester with no activating functionality at the α-position via a product-base mechanism was reported.
Self condensation of
enamines mediated by acetylation. A novel approach to 1-(azol-5-yl)-(1E,3Z)-butadiene-4-N,N-dimethylamines
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.
Flow synthesis using gaseous
ammonia in a Teflon AF-2400 tube-in-tube reactor: Paal–Knorr pyrrole formation and gas concentration measurement by inline flow titration
Permeation of ammonia through Teflon AF-2400 (which is temperature and solvent dependent) facilitated the continuous flow Paal–Knorr synthesis of pyrroles.
1,2,4-triazines and the triazinoisoquinolinedione DEF ring system of noelaquinone
The intramolecular Staudinger-aza-Wittig reaction was used for the first preparation of the DEF ring system of noelaquinone.
Amphiphilic α-helix mimetics based on a benzoylurea scaffold
The design and synthesis of conformationally constrained amphiphilic benzoylurea α-helix mimetics is described.
oxazole– nitrile conversion downstream of rhizoxin biosynthesis and its impact on antimitotic activity
In the endofungal bacterium Burkholderia rhizoxinica novel rhizoxin derivatives with unusual nitrile substitutions are formed by a rare photochemical transformation.
Selective thioether macrocyclization of
peptides having the N-terminal 2-chloroacetyl group and competing two or three cysteine residues in translation
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.
Synthesis and structure–activity relationships of o-sulfonamido-arylhydrazides as
inhibitors of LL-diaminopimelate aminotransferase (LL-DAP-AT)
The synthesis of a series of o-sulfonamido-arylhydrazides and their activity as inhibitors of LL-diaminopimelic acid aminotransferase are described.
oxidation of large aromatic hydrocarbon bay regions to bay region quinones: predicted oxygen-sensitivity of hydrogen-terminated carbon nanotubes
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.
peptide forms a high-affinity binding site for thioflavin-T at the N-terminus
We report the first observation of direct molecular contacts between ThT and model peptide aggregates by applying solid-state NMR spectroscopy.
triflate esters and triflamides with an organic neutral super-electron-donor
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.
Convergent diastereoselective preparation of adjacent quaternary stereocenters in an acyclic system
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..
Tuning and predicting biological affinity:
aryl nitriles as cysteine protease inhibitors
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.
Observation of neighboring ortho-hydroxyl group participation in organocatalytic asymmetric sequential Michael-lactonization reactions: synthesis of highly substituted chiral spirodihydrocoumarins
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 general electron transfer
reduction of lactones using SmI2–H2O
A selective method for the reduction of lactones of all ring sizes and topologies using SmI2–H2O and a Lewis base is described.
The direct catalytic asymmetric aldol reaction of α-substituted nitroacetates with aqueous formaldehyde under base-free neutral phase-transfer conditions
Enantioselective direct aldol reaction of α-substituted nitroacetates with aqueous formaldehyde has been achieved under base-free neutral phase-transfer conditions.
Water-soluble, deep-red fluorescent
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.
Chemoselective Staudinger-phosphite reaction of symmetrical glycosyl-phosphites with azido-
peptides and polygycerols
In this paper we present the synthesis of glyco-phosphoramidate conjugates as easily accessible analogs of glyco-phosphorous esters via the Staudinger-phosphite reaction.
Reactive intermediates in the H-phosphonate synthesis of oligonucleotides
The formation of H-phosphonate diesters is an important step in the synthesis of oligonucleotides.
Ionization state of the catalytic dyad Asp25/25′ in the HIV-1 protease:
NMR studies of site-specifically 13C labelled HIV-1 protease prepared by total chemical synthesis
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.
Formation of luminescent terbium(III) self-assemblies from pyridyl bis-amidothioureas based
ligands in MeOH and in water–DMSO solutions and their use in anion sensing application
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.
inhibitors encompassing novel conformationally-locked 5′-acyl sulfamoyl adenosines
3′-endo-Sugar-locked 5′-acyl sulfamoyl adenosines inhibit Trypanosoma and Leishmania with IC50s of 0.25–0.51 μM.
Vinyl-triphenylamine dyes, a new family of switchable fluorescent probes for targeted two-photon cellular imaging: from DNA to protein labeling
A new family of nonlinear fluorescent probes for specific DNA or protein labeling was designed by structure space exploration around the vinyl-triphenylamine core.
isoxazoles en route to semi-aromatized polyketides: dehydrogenation of benzonitrile oxide– para-quinone acetal cycloadducts
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.
self-assembly and co-assembly of fluorinated, preorganized discotics
Fluorinated bipyridine discotics self-assemble into stable helical columnar mesophases and alternating helical assemblies with hydrocarbon bipyridine discotics in fluorinated media.
extraction of left- or right-handed single-walled carbon nanotubes by use of chiral diporphyrin nanotweezers
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.
proline and prolinol ether mediated 3-component synthesis of 3- and 3,4-substituted chromenone derivatives
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.
Pseudorotaxanes, rotaxanes and metal–organic rotaxane frameworks containing tetra-substituted dibenzocrown-8 wheels
Pseudorotaxanes, 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.
Steric desolvation enhances the effective molarities of intramolecular H-bonding interactions
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.
Synthesis of selective
inhibitors against V. cholerae sialidase and human cytosolic sialidase NEU2
Two inhibitors with selectivity against V. cholerae sialidase and human cytosolic sialidase NEU2, respectively, were identified.
The role of cyclobutenes in gold(I)-catalysed skeletal rearrangement of 1,6-enynes
A bicyclo[3.2.0]hept-5-ene formed in good yield in a gold(I)-catalysed reaction, has been structurally characterised.
Dipicolylamine as a unique structural switching element for helical peptides
A simple method for on-resin synthesis of dipicolylamine (Dpa)-containing peptides was developed, which enables the design of a unique metal-responsive peptide.
Desymmetrizing reductive aldol cyclizations of enethioate derivatives of 1,3-diones catalyzed by a chiral copper hydride
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.
Porphyrin dyads linked by a rotatable 3,3′-biphenyl scaffold: a new binding motif for small ditopic molecules
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.
Synthesis of a
3-deoxy-D-manno-octulosonic acid (KDO) building block from D-glucose via fermentation
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 stereocontrolled total synthesis of spirastrellolide A methyl ester. Fragment coupling studies and completion of the synthesis
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.
The stereocontrolled total synthesis of spirastrellolide A methyl ester. Expedient construction of the key fragments
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.
Amphiphilic dynamic NDI and PDI probes: imaging microdomains in giant unilamellar vesicles
Dynamic amphiphiles with fluorescent naphthalenediimide tails can be used to label membrane microdomains and activate DNA as transporters in lipid bilayers.
Synthesis and evaluation of new polyenic compounds as potential PPARs modulators
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.
Substituent effects on axle binding in
amide pseudorotaxanes: comparison of NMR titration and ITC data with DFT calculations
Guest discrimination: NMR titration and ITC experiments were used to examine the binding behavior of differently disubstituted diamide guests to a tetralactam macrocycle.
Multimodal fluorescence modulation using molecular photoswitches and upconverting nanoparticles
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.
Combined experimental and theoretical studies on the photophysical properties of cycloparaphenylenes
Absorption and fluorescence in solution/solid states. High fluorescence quantum yields. Assignment of UV-vis absorption. Explanation of unique HOMO–LUMO behaviour.
Peptides that anneal to natural collagen in vitro and ex vivo
Collagen mimetic peptides bind tightly to mammalian collagen in vitro and ex vivo, providing a new modality for wound care.
On the origins of diastereoselectivity in the conjugate additions of the antipodes of lithium N-benzyl-(N-α-methylbenzyl)amide to enantiopure cis- and
trans-dioxolane containing α,β-unsaturated esters
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.
Structure, stereochemistry and synthesis of enantiopure cyclohexenone cis-diol bacterial metabolites derived from phenols
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.
Construction of multi-component supramolecular architectures of
bile acids and cinchona alkaloids through helical-pitch-synchronized crystallization
Multi-component organic crystals containing different kinds of helical motifs were constructed based on bile acids and cinchona alkaloids.
Remote stereocontrol in reactions between 4- and 5-alkoxyalk-2-enylstannanes and 1-alkoxycarbonylimines and analogues: stereoselective approaches to novel α-amino acids
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.
Combined coinage metal catalysis in natural product synthesis: total synthesis of
(+)-varitriol and seven analogs
The combined use of the coinage metals copper and gold allows an efficient stereoselective synthesis of (+)-varitriol and various analogs.
Platinum catalyzed 7-endo
cyclization of internal alkynyl amides and its application to synthesis of the caprazamycin core
Considering the synthesis of the caprazamycin core, the scope and limitations of platinum catalyzed 7-endo cyclization of internal alkynyl amides were disclosed.
ligand interactions using thiamine pyrophosphate analogues
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.
Design, synthesis and biological evaluation of non-natural modulators of quorum sensing in Pseudomonas aeruginosa
Novel potent antagonists of quorum sensing in Pseudomonas aeruginosa are reported, which strongly inhibit the production of virulence factors.
Synthetic studies towards the mulberry Diels–Alder adducts: H-bond accelerated cycloadditions of chalcones
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.
Solvent and substituent effects on aggregation constants of perylene bisimide π-stacks – a linear free energy relationship analysis
In this article we have intensively addressed the question how solvents effect the aggregation strength of perylene bisimides.
Enantioselective synthesis of 2,5-dihydrobenzo[b]azepine derivatives via iridium-catalyzed asymmetric allylic
amination with 2-allylanilines and ring-closing-metathesis reaction
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.
glycopeptides: conformational analysis and bioactivity as lectin ligands
NMR and modelling give new insights on the molecular recognition of unnatural α-Gal-N-linked glycopeptides by lectins.
cyclization of unprotected linear peptides by α-ketoacid– hydroxylamine amide-ligation
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.
Double stranded polymeric ladderphanes with 16-π-electron antiaromatic metallocycle linkers
Three double stranded polymeric ladderphanes with 16-π-electron antiaromatic metallocycle linkers are synthesised by ring opening metathesis polymerisation of the corresponding bisnorbornene monomers.
Enantioselective synthesis of C-linked spiroacetal-
triazoles as privileged natural product-like scaffolds
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.
Benzimidazole-based anion receptors: tautomeric switching and selectivity
Tautomeric switching is observed in a series of benzimidazole-based anion receptors upon addition of basic anions.