Aldoximes enable proton-relayed NMR hyperpolarisation.

NMR signals can be greatly enhanced, or hyperpolarised, by interactions with -hydrogen. We demonstrate here that oximes can be reversibly hyperpolarised by coordination to an iridium complex, that oxime / geometry is significant for activity, and that hyperpolarised oximes can subsequently transfer these enhanced signals through proton exchange.

Iridium Pyridylpyrrolides Hyperpolarised by Para-Hydrogen.

Chemical activation of the nuclear singlet state of dihydrogen, para-hydrogen, can dramatically increase the sensitivity of magnetic resonance spectroscopy and imaging. Here, we show that the highly reversible activation of para-hydrogen by an iridium pyridylpyrrolide complex is capable of producing this hyperpolarisation effect. Bound alkene ligands exhibit signal enhancement without reduction to alkanes, which is in contrast to the most widely used hyperpolarisation catalysts.

Benzoquinone Enhances Hyperpolarization of Surface Alcohols with Para-Hydrogen.

The nuclear singlet state of H, para-hydrogen, can be used to increase the measurable signal-to-noise for magnetic resonance techniques─a form of hyperpolarization. Transfer of this polarization from para-hydrogen to alcohols through surface interactions rather than formal hydrogenation has only been demonstrated on heterogeneous catalysts tailored to minimize loss of spin order. Here, we find that a common platinum-on-carbon catalyst is capable of this interaction and that the addition of a benzoquinone significantly increases the signal output of hyperpolarized methanol or water.

Anticancer Activities of Tetrasubstituted Imidazole-Pyrimidine-Sulfonamide Hybrids as Inhibitors of EGFR Mutants.

A new series of tetrasubstituted imidazole derivatives carrying pyrimidine sulfonamide pharmacophores has been synthesized and evaluated for their anticancer activities. In-vitro screening of these hybrids against a full 60-cell-line panel at a single dose of 10 μM showed significant growth inhibition of up to 95 %. The most active compound showed in-vitro anticancer activities against (i) abnormal HER2 and (ii) two mutants for EGFR.

Selective NMR detection of individual reaction components hyperpolarised by reversible exchange with para-hydrogen.

NMR spectroscopy can sometimes be hampered by two inherent weaknesses: low sensitivity and overlap of signals in complex mixtures. Hyperpolarisation techniques using para-hydrogen (including the method known as SABRE) can overcome this sensitivity problem, but cannot circumvent spectral overlap. Conversely, a recently described selective excitation technique (known as DREAMTIME) can overcome overlap in mixtures, but suffers from a decrease in sensitivity.

Current electrochemical approaches to selective deuteration.

The selective deuteration of organic molecules through electrochemistry is proving to be an effective alternative to conventional H labelling strategies, which traditionally require high temperatures, high pressures of deuterium gas in hydrothermal autoclave reactors, or require reagents capable of generating highly reactive species which are then quenched by a deuterium source. Such harsh conditions or reagents can consequently lower chemo- or regioselectivity in many deuteration processes. Transition metal catalysis and more recently photocatalysis have emerged as methods to access selectively deuterated compounds under significantly more mild conditions.

Simple acyclic molecules containing a single charge-assisted O-H group can recognize anions in acetonitrile : water mixtures.

Hydroxypyridinium and hydroxyquinolinium compounds containing acidic O-H groups attached to a cationic aromatic scaffold were synthesized, i.e. N-methyl-3-hydroxypyridinium (1) and N-methyl-8-hydroxyquinolinium (2).

Recent advances in the chemistry of benzo[e][1,2,4]triazinyl radicals.

Benzo[e][1,2,4]triazinyl, or Blatter radicals, are stable free radicals, first reported by Blatter in 1968. In contrast to their nitroxide counterparts, their properties can be modified more widely and more easily through simple substitution changes. This, together with recent developments in their synthesis, now places them at the forefront of developing applications in functional materials.

TEMPO-Me: An Electrochemically Activated Methylating Agent.

Bench- and air-stable 1-methoxy-2,2,6,6-tetramethylpiperidine (TEMPO-Me) is relatively unreactive at ambient temperature in the absence of an electrochemical stimulus. In this report, we demonstrate that the one-electron electrochemical oxidation of TEMPO-Me produces a powerful electrophilic methylating agent in situ. Our computational and experimental studies are consistent with methylation proceeding via a S2 mechanism, with a strength comparable to the trimethyloxonium cation.