Adducing Knowledge Capabilities of Instrumental Techniques Through the Exploration of Heterostructures' Modification Methods.

The ongoing evolution of technology has facilitated the global research community to rapidly escalate the constant development of novel advancements in science. At the forefront of such achievements in the field of photocatalysis is the utilisation, and in oftentimes, the adaptation of modern instrumentation to understand photo-physical properties of complex heterostructures. For example, coupling in-situ X-ray Raman scattering spectroscopy for real-time degradation of catalytic materials.

Enhancing the photo-efficacy of an organic visible-light-activated chromophore (alizarin red S) on zinc oxide with a Ag-Na electrolyte to photo-transform aromatic and aliphatic alcohols.

The development of an aqueous silver-sodium/alizarin red sensitised zinc oxide system has been reported to oxidise a range of both aromatic and aliphatic alcohols to aldehydes. Furthermore, photoluminescence spectroscopy validated the electron quenching effect of zinc oxide's defect sites after surface sensitising the metal-oxide with alizarin red. Powder diffuse reflectance UV/Vis data further substantiated the visible-light attenuated properties of alizarin red sensitised zinc oxide, and hence justification for its visible light reactivity towards alcohol oxidations. Lastly, density functional theory calculations supported the intermolecular photo-electronic transfer between alizarin red organic and zinc oxide.

Solution Conformations of Curcumin in DMSO.

NAMFIS (NMR Analysis of Molecular Flexibility In Solution) has been applied to curcumin dissolved in DMSO. Quantitative 1H-1H distance constraints reduce a pool of candidate conformations to a solution collection of four enol conformations-two of these match curcumin crystallized with human transthyretin, and one is closely related to a single-crystal structure of curcumin.

The 'Ireland' one-pot alcohol oxidation coupling reactions: celebrating 30 years of diverse synthesis.

In 1985, Robert Ireland and co-worker were devising synthetic routes to polyether ionophore antibiotics and during this process several highly reactive aldehydes were encountered, which made their isolation and subsequent elaboration difficult. To circumvent this problem, the synthetic route commenced from the alcohol which was oxidized to the aldehyde and, to the crude mixture, was added the nucleophile. This procedure, dubbed the 'Ireland' oxidative process was found to be highly successful and adapted by many research groups the world over. As we celebrate 30 years since this landmark discovery, the following review will take a journey of the most innovative and wonderful applications of this process.

Palladium-catalysed cross-coupling reaction of ultra-stabilised 2-aryl-1,3-dihydro-1H-benzo[d]1,3,2-diazaborole compounds with aryl bromides: A direct protocol for the preparation of unsymmetrical biaryls.

There has been a significant interest in organoboron compounds such as arylboronic acids, arylboronate esters and potassium aryltrifluoroborate salts because they are versatile coupling partners in metal-catalysed cross-coupling reactions. On the other hand, their nitrogen analogues, namely, 1,3,2-benzodiazaborole-type compounds have been studied extensively for their intriguing absorption and fluorescence characteristics. Here we describe the first palladium-catalysed Suzuki-Miyaura cross-coupling reaction of easily accessible and ultra-stabilised 2-aryl-1,3-dihydro-1H-benzo[d]1,3,2-diazaborole derivatives with various aryl bromides. Aryl bromides bearing electron-withdrawing, electron-neutral and electron-donating substituents are reacted under the catalytic system furnishing unsymmetrical biaryl products in isolated yields of up to 96% in only 10 minutes.

2-(3-Meth-oxy-phen-yl)-1,3-dihydro-1,3,2-benzodiaza-borole.

The title compound, C(13)H(13)BN(2)O, is one in a series of 1,3,2-benzodiaza-boroles featuring a 2-meth-oxy-phenyl substitution at the 2-position in the nitro-gen-boron heterocyle. The dihedral angle between the mean planes of the benzodiaza-borole and 2-meth-oxy-phenyl ring systems is 21.5 (1)°. There is an inter-molecular hydrogen bond between one of the NH groups and the meth-oxy O atom. This hydrogen bond leads to an infinite hydrogen-bonded chain colinear with the a axis.

Convenient photooxidation of alcohols using dye sensitised semiconductors in combination with silver nitrate and TEMPO--an electron paramagnetic resonance study.

A mechanistic investigation into the photooxidation of alcohols using dye sensitised titanium dioxide and dye sensitised zinc oxide is described. The varying yields using the two photocatalysts have been explained using electron paramagnetic resonance (EPR) spectroscopy, which indicated that electron injection occurs in the dye sensitised ZnO system but is sluggish in the dye sensitised TiO(2) system. Due to the failure of the electron injection step, a 'break' in the photooxidative system occurs resulting in a decrease in the conversion of benzyl alcohol to benzaldehyde for the dye sensitised TiO(2) system.

Convenient photooxidation of alcohols using dye sensitised zinc oxide in combination with silver nitrate and TEMPO.

A novel photooxidative system using dye sensitised zinc oxide in combination with silver nitrate and 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) in an aqueous solution is described. Under visible light irradiation the selective oxidation of alcohols to their corresponding aldehydes and ketones was effected in good to excellent yields.

2-(4-Chloro-phen-yl)naphtho-[1,8-de][1,3,2]diaza-borinane.

The title compound, C(16)H(12)BClN(2), is one in a series of diaza-borinanes, derived from 1,8-diaminona-phthalene, featuring substitution at the 1, 2 and 3 positions in the nitro-gen-boron heterocycle. The structure deviates from planarity, the torsion angle subtended by the p-chloro-phenyl ring relative to the nitro-gen-boron heterocycle being -44-.3(3)°. The mol-ecules form infinite chains with strong inter-actions between the vacant pz orbital of the B atom and the π-system of an adjacent mol-ecule. The distance between the B atom and the 10-atom centroid of an adjacent naphthalene ring is 3.381 (4) Å. One N-H H atom is weakly hydrogen bonded to the Cl atom of an adjacent mol-ecule. This combination of inter-molecular inter-actions leads to the formation of an infinite two-dimensional network perpendic-ular to the c axis.

2-Phenyl-naphtho-[1,8-de][1,3,2]diaza-borinane.

The title compound, C(16)H(13)BN(2), is one compound in a series of diaza-borinanes featuring substitution at the 1, 2 and 3 positions in the nitro-gen-boron heterocycle. The title compound is slightly distorted from planarity, with a dihedral angle of 9.0 (5)° between the mean planes of the naphthalene system and the benzene ring. The m-carbon atom of the benzene ring exhibits the greatest deviation of 0.164 (2) Šfrom the 19-atom mean plane defined by all non-H atoms. The two N-B-C-C torsion angles are 6.0 (3) and 5.6 (3)°. In the crystal, mol-ecules are linked by π-π inter-actions into columns, with a distance of 3.92 (3) Šbetween the naphthalene ring centroids. Adjacent π-stacked columns, co-linear with the b-axis, are linked by C-H⋯π inter-actions.

2-[4-(Methyl-sulfan-yl)phen-yl]naphtho[1,8-de][1,3,2]diaza-borinane.

The title compound, C(17)H(15)BN(2)S, is one member in a series of diaza-borinanes featuring substitution at the 1-, 2- and 3-positions in the nitro-gen-boron heterocycle. The dihedral angle between the mean planes of the naphthalene and phenyl ring systems is 19.86 (6)°. In the crystal structure, two C-H⋯π inter-actions link the mol-ecules into sheets which lie parallel to the bc plane. There is a π-π inter-action between each pair of centrosymmetrically related sheets [centroid-centroid distance = 3.5922 (8) Å].

Green oxidations: titanium dioxide induced tandem oxidation coupling reactions.

The application of titanium dioxide as an oxidant in tandem oxidation type processes is described. Under microwave irradiation, quinoxalines have been synthesized in good yields from the corresponding alpha-hydroxyketones.

Does the DABCO-catalysed reaction of 2-hydroxybenzaldehydes with methyl acrylate follow a Baylis-Hillman pathway?

Evidence is presented which supports the intermediacy of dipolar Baylis-Hillman-type adducts in the synthesis of coumarin and chromene derivatives from the reaction of 2-hydroxybenzaldehydes with methyl acrylate in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO).