An efficient transformation of methyl ethers and nitriles to amides catalyzed by Iron(III) perchlorate hydrate

Influence of Calcium Perchlorate on the Search for Organics on Mars with Tetramethylammonium Hydroxide Thermochemolysis

The Mars Organic Molecule Analyzer (MOMA) and Sample Analysis at Mars (SAM) instruments onboard the Exomars 2022 and Mars Science Laboratory rovers, respectively, are capable of organic matter detection and differentiating potentially biogenic from abiotic organics in martian samples. To identify organics, both these instruments utilize pyrolysis-gas chromatography coupled to mass spectrometry, and the thermochemolysis agent tetramethylammonium hydroxide (TMAH) is also used to increase organic volatility. However, the reactivity and efficiency of TMAH thermochemolysis are affected by the presence of calcium perchlorate on the martian surface. In this study, we determined the products of TMAH pyrolysis in the presence and absence of calcium perchlorate at different heating rates (flash pyrolysis and SAM-like ramp pyrolysis with a 35°C·min^-1 heating rate). The decomposition mechanism of TMAH pyrolysis in the presence of calcium perchlorate was studied by using stepped pyrolysis. Moreover, the effect of calcium perchlorate (at Mars-relevant concentrations) on the recovery rate of fatty acids with TMAH thermochemolysis was studied. Results demonstrate that flash pyrolysis yields more diversity and greater abundances of TMAH thermochemolysis products than does the SAM-like ramp pyrolysis method. There is no obvious effect of calcium perchlorate on TMAH degradation when the [ClO₄^-] is lower than 10 weight percent (wt %). Most importantly, the presence of calcium perchlorate does not significantly impact the recovery rate of fatty acids with TMAH thermochemolysis under laboratory conditions, which is promising for the detection of fatty acids via TMAH thermochemolysis with the SAM and MOMA instruments on Mars.

Recent advances of Ritter reaction and its synthetic applications

This review provides a comprehensive survey of Ritter reactions from 2014 to 2020.

A convenient synthesis of N-tert-butyl amides by the reaction of di-tert-butyl dicarbonate and nitriles catalyzed by Cu(OTf)2

The utility of Cu(OTf)2 as the catalyst for the synthesis of a series of N- tert-butyl amides in excellent isolated yields via the reaction of nitriles (alkyl, aryl, benzyl, and furyl nitriles) with di- tert-butyl dicarbonate is described. Cu(OTf)2 is a highly stable and efficient catalyst for the present Ritter reaction under solvent-free conditions at room temperature.