A non-enzymatic simultaneous kinetic resolution of racemic alkynes and racemic azides utilising an asymmetric CuAAC reaction is reported. The use of a CuCl (R,R)Ph-Pybox catalyst system effects a simultaneous kinetic resolution of two racemic starting materials to give one major triazolic diasteroisomer in the ratio 74:12:4:10 (dr 84:16, 90% ee maj). The corresponding control reaction using an achiral copper catalyst gives the four possible diastereoisomers in a 23:27:23:27 ratio, demonstrating minimal inherent substrate control.

The synthesis of atropisomeric phosphino-triazoles through a CuAAC approach is disclosed. Gold( i ) chloride complexes of single-enantiomer phosphines were then prepared and again demonstrated to be conformationally stable.

The synthesis and characterisation of axially chiral atropisomeric 1,5-disubstituted 1,2,3-triazoles is reported. Molecules designed to display restricted rotation about 1,2,3-triazole N-1-aryl or 1,2,3-triazole C-5-aryl bonds were investigated by physical and computational techniques. The barrier to 1,2,3-triazole N-1-aryl rotation was found to be higher than that for 1,2,3-triazole C-5-aryl rotation, confirming axial chirality stemming from restricted rotation about an N-1-aryl bond in a 1,5-disubstituted 1,2,3-triazole to be the most suitable for the development of an axial chirality triazole-based platform.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Hydroxylative dearomatization reactions of phenols (HPD) offer an efficient way to assemble complex, biologically relevant scaffolds. Despite this, enantioselective hydroxylative phenol dearomatizations for the construction of bicy-clo[2.2.2]octenones are classically limited to stoichiometric chiral reagents, and a practical, enantioselective catalytic method has remained elusive. Herein, we describe a highly enantioselective, organocatalytic tandem o-HPD-[4+2] reaction. Our methodology utilizes a chiral oxaziridinium organocatalyst that affords high enantioselectivity for a wide range of phenol substitution patterns, and was applied in the synthesis of (+)-biscarvacrol and bis(2,6-xylenol). The practicality of our conditions were demonstrated at gram-scale, using an amine precatalyst that can be accessed in a single synthetic step.

The development of electrochemical methods for the carboxylation of a variety of substrates to form new C-CO2 bonds has been an area of interest for a number of years and is a powerful way to construct such a bond, often negating the use of water sensitive/pyrophoric reagents (e.g. metal halogen exchange with alkyl lithium compounds). In this review we will examine the breadth of carboxylation reactions available and the type of electrosynthetic cell and catalyst required to carry out the transformation. Traditionally many of these reactions were carried out using sacrificial magnesium/aluminum or zinc anodes, but recent developments have enabled the circumvention of these non-sustainable approaches and have opened the door toward further development of continuous flow processes. These developments have run alongside the increased availability of standardized batch and flow electrochemical systems now available to the synthetic chemist. Competition between the areas of photocatalysis and electrocatalysis through comparative reactivity of single electron transfer processes has driven many of the new innovations in this exciting area of research.

Electrosynthetic hydrocarboxylation of alpha,beta-unsaturated olefins with excellent regioselectivity is reported. No sacrificial electrode is required and is thus amenable to a flow configuration. The products are purified by simple crystallisation. Synthesis of a precursor to ethosuximide, which contains an all-carbon quaternary centre, illustrates the potential of the process. Finally a robustness study has benchmarked the process for future users.

Due to increasing concentrations in the atmosphere, carbon dioxide has, in recent times, been targeted for utilisation (Carbon Capture Utilisation and Storage, CCUS). In particular, the production of CO from CO2 has been an area of intense interest, particularly since the CO can be utilized in Fischer-Tropsch synthesis. Herein we report that CO2 can also be used as a source of atomic oxygen that is efficiently harvested and used as a waste-free terminal oxidant for the oxidation of alkenes to epoxides. Simultaneously, the process yields CO. Utilization of the atomic oxygen does not only generate a valuable product, but also prevents the recombination of O and CO, thus increasing the yield of CO for possible application in the synthesis of higher-order hydrocarbons.

Novel organic synthesis routes that circumvent the need for a catalyst and reduce unwanted by-products are highly sought by industry. A novel microfluidic plasma reactor that generates a dielectric barrier discharge (DBD) plasma in the vicinity of the gas-liquid interface and facilitate a chemical reaction at the interface of microbubbles has been used for trans-stilbene epoxidation. Three different operating strategies were implemented to optimise the transfer of species selectivity: single pass, multi-pass and continuous recirculation. The effect of initial trans-stilbene concentration, oxygen content in the feed gas mixture and reaction time on the epoxide formation was studied to optimise the chemical reaction. The optimum operating conditions were found to be short bubble-liquid contact times (~2 s) with frequent exposure to freshly generated microbubbles containing reactive species by continuous liquid recirculation, and under these conditions the overall epoxide yield was ~94% with an overall epoxide selectivity of 10:1.

To date the majority of diene carboxylation processes afford the α,δ-dicarboxylated product, the selective mono-carboxylation of dienes is a significant challenge and the major product reported under transition metal catalysis arises from carboxylation at the α-carbon. Herein we report a new electrosynthetic approach, that does not rely on a sacrificial electrode, the reported method allows unprecedented direct access to carboxylic acids derived from dienes at the δ-position. In addition, the α,δ-dicarboxylic acid or the α,δ-reduced alkene can be easily accessed by simple modification of the reaction conditions.

The construction of carboxylic acid compounds in a selective fashion from low value materials such as alkenes remains a long-standing challenge to synthetic chemists. In particular, β-addition to styrenes is underdeveloped. Herein we report a new electrosynthetic approach to the selective hydrocarboxylation of alkenes that overcomes the limitations of current transition metal and photochemical approaches. The reported method allows unprecedented direct access to carboxylic acids derived from β,β-trisubstituted alkenes, in a highly regioselective manner.

Utilizing CO2 in an electro-chemical process and synthesizing value-added chemicals are amongst the few viable and scalable pathways in carbon capture and utilization technologies. CO2 electro-reduction is also counted as one of the main options entailing less fossil fuel consumption and as a future electrical energy storage strategy. The current study aims at developing a new electrochemical platform to produce low-carbon e-biofuel through multifunctional electrosynthesis and integrated co-valorisation of biomass feedstocks with captured CO2. In this approach, CO2 is reduced at the cathode to produce drop-in fuels (e.g., methanol) while value-added chemicals (e.g., selective oxidation of alcohols, aldehydes, carboxylic acids and amines/amides) are produced at the anode. In this work, a numerical model of a continuous-flow design considering various anodic and cathodic reactions was built to determine the most techno-economically feasible configurations from the aspects of energy efficiency, environment impact and economical values. The reactor design was then optimized via parametric analysis.

Plasmas interacting with organic liquids can lead to novel synthetic processes that are not feasible with conventional vacuum systems due to vapor pressure limitations. Of particular interest are processes that eliminate the generation of waste streams. Here, we show that He+O-2 plasma can drive the epoxidation of alkenes in solution, in a process that generates epoxides without oxidant waste streams, runs at room temperature and atmospheric pressure, and requires no catalyst. The reactions between different reactive oxygen species generated in the plasma and the target alkene, trans-stilbene in this study, have been identified and optimization of the plasma conditions within the constraints of the current experimental setup has led to yields of similar to 70%, which are of preparative interest.

Peroxynitrite (ONOO-) is a powerful and short-lived oxidant formed in vivo, which can react with most biomolecules directly. To fully understand the roles of ONOO- in cell biology, improved methods for the selective detection and real-time analysis of ONOO- are needed. We present a water-soluble, luminescent europium(iii) probe for the rapid and sensitive detection of peroxynitrite in human serum, living cells and biological matrices. We have utilised the long luminescence lifetime of the probe to measure ONOO- in a time-resolved manner, effectively avoiding the influence of autofluorescence in biological samples. To demonstrate the utility of the Eu(iii) probe, we monitored the production of ONOO- in different cell lines, following treatment with a cold atmospheric plasma device commonly used in the clinic for skin wound treatment.

A series of phosphino triazoles are disclosed, within which, the phosphorus atom is appended by one, two or three triazole motifs. Gold(I) chloride complexes of the synthesised ligands were prepared and analysed by techniques including single crystal X-ray diffraction structure determination. SambVca (2.0) was used to determine percentage buried volumes. The effectiveness of these gold(I) chloride complexes to serve as precatalysts for alkyne hydration were assessed.

A non-enzymatic simultaneous (coined coetaneous) kinetic resolution of a racemic alkyne and racemic azide, utilising an asymmetric CuAAC reaction is reported. The use of a CuCl (R,R)-Ph-Pybox catalyst system effects a simultaneous kinetic resolution of two racemic starting materials to give one major triazolic diastereoisomer in the ratio 74:12:4:10 (dr 84:16, 90% ee maj). The corresponding control reaction using an achiral copper catalyst gives the four possible diastereoisomers in a 23:27:23:27 ratio, demonstrating minimal inherent substrate control.