348-61-8Relevant articles and documents
High-throughput Synthesis and Screening of Iridium(III) Photocatalysts for the Fast and Chemoselective Dehalogenation of Aryl Bromides
Bernhard, Stefan,Connell, Timothy U.,Diluzio, Stephen,Kowalewski, Jakub F.,Kowalewski, Tomasz,Lewis, Jacqueline,Mdluli, Velabo,Yaron, David
, p. 6977 - 6987 (2020)
A high-throughput optical screening method for the photocatalytic activity of a structurally diverse library of 1152 cationic iridium(III) complexes ([Ir(C^N)2(N^N)]+), corresponding to all combinations of 48 cyclometalating (C^N) and 24 ancillary (N^N) ligands, was developed. This rapid assay utilizes the colorimetric changes of a high contrast indicator dye, coumarin 6, to monitor the photo-induced electron transfer from a sacrificial amine donor to the metal complex excited state. The resulting [Ir(C^N)2(N^N)]0 can then reduce an aryl bromide to form the highly reactive aryl radical intermediate. The rate of this reaction is dictated by the molecular structure of both coordinating ligands. Relative reaction rate constants determined via this method correlated closely with 19F NMR measurements obtained using a fluorinated substrate. A simple model that expresses the rate constant as a product of a single ″strength″ parameter assigned to each of the 72 ligands can well account for the 1152 measured rate constants. The best performing complexes exhibit much higher reactivity than the benchmark photocatalysts commonly used in photoredox transformations. The catalysts were also successfully tested for their chemoselectivity. The developed screening methodology can enable generation of the large data sets needed to use modern data science to extract structure-activity relationships.
PROCESS FOR THE PREPARATION OF ORGANIC BROMIDES
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Paragraph 00139, (2017/07/28)
The present invention provides a process for the preparation of organic bromides, by a radical bromodecarboxylation of carboxylic acids with a bromoisocyanurate.
Bromination of aromatic compounds using an Fe2O 3/zeolite catalyst
Nishina, Yuta,Takami, Keishi
supporting information, p. 2380 - 2383 (2013/02/21)
The catalytic bromination of non-activated aromatic compounds has been achieved using an Fe2O3/zeolite catalyst system. FeBr 3 was identified as the catalytic species, formed in situ from HBr and Fe2O3. The catalyst was easy-to-handle and cost effective and could also be recycled. The reaction system was also amenable to the one-pot sequential bromination/C-C bond formation of benzene.
