Australian Journal of Chemistry
Volume 68 Number 12 2015
RESEARCH FRONT: SynthCon3
In April 2015, the third instalment of the biennial SynthCon meeting, SynthCon3, was held at Fergusson's Winery in the Yarra Valley. This Research Front showcases the latest developments in synthetic organic chemistry research from the meeting.
CH15389Brønsted Acid-Mediated Radical Processes in Organic Synthesis
This highlight focuses on applications of Brønsted acid-mediated radical processes across a range of reaction manifolds. A brief overview of significant research developments in the area and a discussion of the key mechanistic features of notable transformations are provided.
CH15363Rhodium(II) Azavinyl Carbenes and their Recent Application to Organic Synthesis
Rhodium(II) azavinyl carbenes are emerging as extremely useful intermediates to access a wide range of heterocycles and other scaffolds. This highlight provides a broad overview of their recent application in organic synthesis.
Allyl sulfides have emerged as useful promoters for olefin metathesis. This review highlights how the enhanced reactivity of allyl sulfides in olefin metathesis has been leveraged in organic synthesis, medicinal chemistry, and chemical biology.
CH15393Iridium-Catalyzed Triborylation of 3-Substituted Indoles
Readily available 3-substituted indoles undergo a regioselective, iridium-catalyzed triborylation at the C2, C5, and C7 sites, providing tetrasubstituted indoles in a single step.
CH15397Complete Stereocontrol in the Synthesis of Harmonine and Novel Analogues Facilitated by a Grubbs Z-Selective Cross-Metathesis Catalyst
(R)-Harmonine was synthesised in 15 % overall yield via a six-step sequence exploiting a Z-selective cross-metathesis reaction as its centrepiece. By this strategy, the cis-olefin present in the target could be installed exclusively. This method was also used to prepare two novel analogues of harmonine.
CH15407Studies Towards a Concise Enantioselective Synthesis of Roseophilins
An oxazolidone auxiliary-controlled asymmetric Nazarov reaction has been applied to the synthesis of the cyclopentyl-fused pyrrole core of the roseophilins, and a concise synthetic route to the pyrrole-furan biaryl fragment required in the synthesis of dechlororoseophilin is described. It is anticipated that these two syntheses can be combined in future efforts to provide efficient, convergent access to (+)-dechlororoseophilin.
CH15461The Synthesis and Biological Evaluation of Anithiactin A/Thiasporine C and Analogues
The synthesis of anithiactin A has been achieved in four steps. Several closely related analogues were synthesised and their biological activity against colon and breast cancer cell lines evaluated. Anithiactin A was found to not be cytotoxic even at a high concentration (100 μM); however, two 4-substituted phenyl thiazoles were found to be moderately cytotoxic at 10 μM.
CH15475Thiol-Reactive Analogues of Galanthamine, Codeine, and Morphine as Potential Probes to Interrogate Allosteric Binding within Nicotinic Acetylcholine Receptors
Galanthamine and codeine are reported to be positive allosteric modulators of nicotinic acetylcholine receptors (nAChRs), but their binding sites are not well defined. Thiol-reactive probes that are suitable for covalent trapping, an extension of the substituted cysteine accessibility method, are prepared to elucidate the allosteric binding sites of galanthamine and codeine at nAChRs.
CH15459Exploring the Catalytic Reactivity of Nickel Phosphine–Phosphite Complexes
An investigation into various nickel phosphite and phosphite–phosphine complexes for use in the Mizoroki–Heck and Suzuki–Miyaura cross-coupling reactions and the ammonia arylation reaction is reported.
CH15504Steric and Electronic Effects in the Synthesis and Regioselective Hydrolysis of Unsymmetrical Imides
The AgI-promoted coupling reaction of thioamides and carboxylic acids is shown to be a useful method for the generation of unsymmetrical imides, which can then be converted into amides or other carboxylic acid derivatives. An interplay of both steric and electronic effects is observed in both the imide formation and subsequent solvolysis, allowing for optimization of yield and control of regioselectivity.
CH15465Synthesis of Non-Symmetrical and Atropisomeric Dibenzo[1,3]diazepines: Pd/CPhos-Catalysed Direct Arylation of Bis-Aryl Aminals
Pd/CPhos-catalysis provides direct arylation/cyclisation of methylene-linked bis-anilines to dibenzo[1,3]diazepines, which are both non-(C2)-symmetrical and axially chiral. The cyclic targets are formed by heating (ortho-halo)aryl-aminal-linked arenes and potassium carbonate in dimethylacetamide in the presence of palladium acetate and CPhos. This method appears to be the first reported for the synthesis of this class of heterocycles in a C1-(a)symmetric manner.
CH15489Carborane-Containing Hydroxyamidine Scaffolds as Novel Inhibitors of Indoleamine 2,3-Dioxygenase 1 (IDO1)
Two new carborane-containing hydroxyamidines were prepared as potential inhibitors of the indoleamine 2,3-dioxygenase 1 (IDO1) enzyme.
CH15587Unexpected Isomerisation of a Fragment Analogue During Fragment-Based Screening of HIV Integrase Catalytic Core Domain
Fragment-based screening of human immunodeficiency virus type 1 (HIV) integrase revealed a hit analogue that bound in an isomerised form to the LEDGF binding site. The starting lactone was stable in CDCl3; however, it unexpectedly isomerised in [D6]DMSO to give the same carboxylic acid as that found in the LEDGF binding site.
CH15434Synthesis and Properties of Photoswitchable Carbohydrate Fluorosurfactants
A new family of photoswitchable carbohydrate fluorosurfactant is described. Novel fluorosurfactants were synthesised using the copper(i)-catalysed azide–alkyne cycloaddition reaction and were isolated in moderate to high yields. These materials displayed unusual photocontrollable surface tension and selective antibacterial activity that was dependent on the carbohydrate and regiochemistry of the fluoroalkyl group.
CH15468Studies Toward the Total Synthesis and Stereochemical Assignment of Microspinosamide
Efforts toward the total synthesis and stereochemical assignment of the cyclic depsipeptide natural product microspinosamide are described. A native chemical ligation–oxidation sequence was used to assemble a potential diastereoisomer from two fragments, a cyclic depsipeptide and a linear peptide thioester.
CH15490Rapid Microwave-Assisted Synthesis of N-Aryl 1,2,3,4-Tetrahydroisoquinolines
Rapid access to a range of N-aryl 1,2,3,4-tetrahydroisoquinolines via the Pd-catalysed coupling of (hetero)aryl iodides or bromides under microwave-assisted conditions is described.
CH15079Investigation of the Effects of Various Cyclodextrins on the Stabilisation of Human Serum Albumin by a Spectroscopic Method
The binding parameters between cyclodextrins (CDs) and human serum albumin (HSA) were investigated. The obtained heats for HSA+CDs interactions were reported and analysed in terms of the extended solvation model. The binding constants and thermodynamic parameters were obtained.
CH15107Structure, Chemical Composition, and Catalytic Behaviour of Stoichiometric and Non-Stoichiometric LaMnO3 Toward Deep Oxidation of Ethanol
Three kinds of Mn-containing perovskites La0.8MnO3–δ, LaMnO3+δ and LaMn0.8O3–δ have been investigated for ethanol deep oxidation in the temperature range 100–300°C. La0.8MnO3-δ shows the best catalytic activity, due to its low surface basicity (lowest La/Mn ratio) and high redox properties (highest Mn4+/Mn3+ ratio).
CH15154Improving Cycling Performance of LiMn2O4 Battery by Adding an Ester-Functionalized Ionic Liquid to Electrolyte
LiMn2O4 has attracted great attention because of its excellent merits for application in lithium-ion batteries. However, it suffers from rapid capacity fading during electrochemical cycling. In this article, N-methylpyrrolidinium-N-acetate bis(trifluoromethylsulfonyl)imide was designed as an additive to electrolyte for improving the electrochemical performance of Li/LiMn2O4 half-cells.
CH15102The Cooperative Effect in Dendronized Chitosan Microbeads
Dendronized chitosan beads are synthesized and used for Cu2+ adsorption. The cooperative effect is observed due the proximity of the periphery groups of the dendron, and a significant contribution to catalysis is due to the presence of the dendron.
CH15520Mn(II)2Gd(III)3 Phosphonate as a Molecular Refrigerant
A planar pentanuclear {Mn2Gd3} cluster was built by using a bulky phosphonic acid. The structure and magnetic properties were characterised. This cluster shows a large MCE with ΔS = 20.9 J kg–1 K–1 at ΔH = 7 T.