6961-42-8Relevant articles and documents
Studies of hydrogen isotope scrambling during the dehalogenation of aromatic chloro-compounds with deuterium gas over palladium catalysts
Lockley, William J.S.,Venanzi, Niccolò A. E.,Crane, Georgie J.
, p. 531 - 552 (2020/09/22)
Catalytic dehalogenation of aromatic halides using isotopic hydrogen gas is an important strategy for labelling pharmaceuticals, biochemicals, environmental agents and so forth. To extend, improve and further understand this process, studies have been carried out on the scrambling of deuterium isotope with protium during the catalytic deuterodehalogenation of model aryl chlorides using deuterium gas and a palladium on carbon catalyst in tetrahydrofuran solution. The degree of scrambling was greatest with electron-rich chloroarene rings. The tetrahydrofuran solvent and the triethylamine base were not the source of the undesired protium; instead, it arose, substantially, from the water content of the catalyst, though other sources of protium may also be present on the catalyst. Replacement of the Pd/C catalyst with one prepared in situ by reduction of palladium trifluoroacetate with deuterium gas and dispersed upon micronised polytetrafluoroethylene led to much reduced scrambling (typically 0–6% compared with up to 40% for palladium on carbon) and to high atom% abundance, regiospecific labelling. The improved catalytic system now enables efficient polydeuteration via the dehalogenation of polyhalogenated precursors, making the procedure viable for the preparation of MS internal standards and, potentially, for high specific activity tritium labelling.
N-Heterocyclic carbene catalysed aerobic oxidation of aromatic aldehydes to aryl esters using boronic acids
Arde, Panjab,Ramanjaneyulu,Reddy, Virsinha,Saxena, Apurv,Anand, R. Vijaya
supporting information; experimental part, p. 848 - 851 (2012/02/05)
The organocatalytic behavior of N-heterocyclic carbenes in the aerobic oxidation of aromatic aldehydes to esters with boronic acids has been explored. This transition metal-free protocol allows access to a wide variety of aromatic esters in good to excellent yields under mild reaction conditions.
Synthesis and crystal structure of [5-chloro-2-(4-nitrobenzyloxy)-phenyl]- (4-chloro-phenyl) methanone
Neetha,Venu,Sridhar,Shashidhara Prasad,Shashikanth
scheme or table, p. 143 - 150 (2012/08/08)
The title compound, C20H13Cl2NO 4, crystallizes in the monoclinic crystal system and space group P21/n with cell parameters a = 9.434(2) A, b = 13.167(3) A, c = 15.087(4) A, β = 105.289(8)°, V = 1807.