143418-49-9Relevant articles and documents
Mechanistic insights into boron-catalysed direct amidation reactions
Arkhipenko, Sergey,Sabatini, Marco T.,Batsanov, Andrei S.,Karaluka, Valerija,Sheppard, Tom D.,Rzepa, Henry S.,Whiting, Andrew
, p. 1058 - 1072 (2018)
The generally accepted monoacyloxyboron mechanism of boron-catalysed direct amidation is brought into question in this study, and new alternatives are proposed. We have carried out a detailed investigation of boron-catalysed amidation reactions, through study of the interaction between amines/carboxylic acids and borinic acids, boronic acids and boric acid, and have isolated and characterised by NMR/X-ray crystallography many of the likely intermediates present in catalytic amidation reactions. Rapid reaction between amines and boron compounds was observed in all cases, and it is proposed that such boron-nitrogen interactions are highly likely to take place in catalytic amidation reactions. These studies also clearly show that borinic acids are not competent catalysts for amidation, as they either form unreactive amino-carboxylate complexes, or undergo protodeboronation to give boronic acids. It therefore seems that at least three free coordination sites on the boron atom are necessary for amidation catalysis to occur. However, these observations are not consistent with the currently accepted 'mechanism' for boron-mediated amidation reactions involving nucleophilic attack of an amine onto a monomeric acyloxyboron intermediate, and as a result of our observations and theoretical modelling, alternative proposed mechanisms are presented for boron-mediated amidation reactions. These are likely to proceed via the formation of a dimeric B-X-B motif (X = O, NR), which is uniquely able to provide activation of the carboxylic acid, whilst orchestrating the delivery of the amine nucleophile to the carbonyl group. Quantum mechanical calculations of catalytic cycles at the B3LYP+D3/Def2-TZVPP level (solvent = CH2Cl2) support the proposal of several closely related potential pathways for amidation, all of which are likely to be lower in energy than the currently accepted mechanism.
PROCESS FOR THE PREPARATION OF BIPHENYLAMINES
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Page/Page column 23-24, (2021/01/29)
The invention relates to a method for the preparation of 2-aminobiphenyls, key intermediates in the preparation of compounds of interest in the agrochemical industry. The process comprises reacting an ortho-substituted aniline and a phenylboro derivative in the presence of a base and a palladium catalyst, said palladium catalyst comprising a palladium source and a biphenyl phosphine ligand of formula (III) or a salt thereof
A 3 ', 4', 5' - trifluoro -2 - amino biphenyl chemical synthesis method
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Paragraph 0061-0069, (2019/07/11)
The invention discloses a 3 ', 4', 5 '- trifluoro - 2 - amino biphenyl chemical synthesis method, it to 3, 4, 5 - trifluoro bromobenzene as the starting material, passes through formatting reaction, reaction and coupling reaction to obtain a sediment 3', 4 ', 5' - trifluoro - 2 - nitro-biphenyl, 3 ', 4', 5 '- trifluoro - 2 - nitro-biphenyl through catalytic reduction reaction to obtain the target product 3', 4 ', 5' - trifluoro - 2 - phenylaniline. The present invention provides compound 3 ', 4', 5' - trifluoro - 2 - amino biphenyl synthesis of new routes, the advantages of the simple process operation, mild reaction conditions, high yield, is simple in separation purification. Wherein the 3 ', 4', 5' - trifluoro - 2 - nitro-biphenyl synthesis in the process, the catalyst consumption is low, and the production cost is reduced, more suitable for large-scale industrial application.