Novel one pot synthesis of 2-amino-4-chloroquinolines via Smiles rearrangement

We have developed a novel one pot synthesis of 4-chloroquinolin-2-ylamines via Smiles rearrangement under milder condition. The key transformation involves O-alkylation of 4-chloro-1H-quinolin-2-ones with chloroacetamide followed by Smiles rearrangement. The scope of this methodology is further extended to the synthesis of 4-chloroquinolin-2-ylmethylamines and 2-(4-chloroquinolin-2-ylamino)ethanols. This methodology has furnished good yields of 2-amino-4-chloroquinolines.     

Crystal phase-controlled synthesis of Cu2FeSnS4 nanocrystals with a band gap of around 1.5 eV

Cu(2)FeSnS(4) (CFTS) nanocrystals with tunable crystal phase have been synthesized using a solution-based method. As-synthesized CFTS nanocrystals in the shape of oblate spheroid and triangular plate with band gaps of 1.54 ± 0.04 and 1.46 ± 0.03 eV, respectively, appear attractive as a low-cost substitute for thin film solar cells.     

Syntheses and magnetic properties of Cr2Te3 and CuCr2Te4 nanocrystals

The Cr-based tellurides are attractive material systems for fundamental studies and potential applications. Colloidal syntheses of ferromagnetic Cr(2)Te(3) and CuCr(2)Te(4) nanocrystals with uniform morphology and narrow size distribution are reported together with their detailed magnetic characterisation.     

Cross polarization from spins I=12 to spins S=1 in nuclear magnetic resonance with magic angle sample spinning

Spin locking of the nuclear magnetization of a spin with S=1 such as deuterium in the presence of a radio-frequency field under magic angle spinning (MAS) is described in terms of adiabatic modulations of the energy levels. In a brief initial period, part of the initial density operator nutates about the Hamiltonian and is dephased. The remaining spin-locked state undergoes persistent oscillatory transfer processes between various coherences with a periodicity given by the rotation of the sample. While all crystallites in the powder undergo such periodic transfer processes, the phases of the oscillations depend on the angle gamma of the crystallites. The angle gamma is the azimuthal angle defining the orientation of the unique axis of the quadrupolar interaction tensor in a rotor-fixed frame. The theory is extended to describe cross-polarization between spins S=1 and I=12 under MAS. There are four distinct Hartmann-Hahn matching conditions that correspond to four zero-quantum matching conditions, all of which are shifted and broadened compared to their spin S=12 counterparts. These matching conditions are further split into a family of sideband conditions separated by the spinning frequency. The theory allows the calculation of both shifts and broadening factors of the matching conditions, as verified by simulations and experiments.     

Electrochemically promoted Friedel-Crafts acylation of aromatic compounds

Friedel-Crafts acylation is carried out with several aromatic substrates in the presence of an electrochemically active aluminium anode to minimize the inorganic reagents. Only a catalytic amount of AlCl₃ (5 mol %) is required to enable the anodic polarization of the aluminium electrode to promote continuous acylation. This process typically gave products in good yields (70-96%).     

An Enolate‐Mediated Organocatalytic Azide–Ketone [3+2]‐Cycloaddition Reaction: Regioselective High‐Yielding Synthesis of Fully Decorated 1,2,3‐Triazoles

An enolate‐mediated organocatalytic azide–ketone [3+2]‐cycloaddition (OrgAKC) reaction of a variety of enolizable arylacetones and deoxybenzoins with aryl azides was developed for the synthesis of fully decorated 1,4‐diaryl‐5‐methyl(alkyl)‐1,2,3‐triazoles in excellent yields with high regioselectivity at 25 °C for 0.5–6 h. This reaction has an excellent outcome with reference to reaction rate, yield, regioselectivity, operation simplicity, and availability of substrates and catalyst. This reaction has advantages over the previously known metal‐mediated reactions.     

Coaxing Solid‐State Phosphorescence from Tellurophenes

The synthesis of the first examples of tellurophenes exhibiting phosphorescence in the solid state and under ambient conditions (room temperature and in air) is reported. Each of these main‐group‐element‐based emitters feature pinacolboronates (BPin) as ring‐appended side groups. The nature of the luminescence observed was also investigated using computational methods.