3717-60-0Relevant articles and documents
Cobalt complex, preparation method thereof, and application thereof in selective catalysis of transfer hydrogenation reaction of cyano group
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Paragraph 0181-0184, (2018/05/07)
The invention discloses a cobalt complex, a preparation method thereof, and an application thereof in the selective catalysis of a transfer hydrogenation reaction of a cyano group. The structural formula of the cobalt complex is represented by formula I. The cobalt complex is prepared through a reaction of a cobalt salt and an NNP ligand or a PNP ligand under the protection of an inert atmosphere;and the chemical formula of the cobalt salt is CoX12, wherein X1 represents halogen, a sulfate radical, a perchlorate radical, a hexafluorophosphate radical, a hexafluoroantimonate radical, a tetrafluoroborate radical, a trifluoromethanesulfonate radical or a tetra(pentafluorophenyl)borate radical. The cobalt complex can be used in the selective catalysis of the transfer hydrogenation reaction ofthe cyano group to obtain a primary amine compound, a secondary amine compound and a tertiary amine compound, the primary amine compound, the secondary amine compound and the tertiary amine compoundare important intermediates in a series of subsequent functionalizing reactions, and the cobalt complex has a very high catalysis activity, and has great research values and a great application prospect.
Expanding Water/Base Tolerant Frustrated Lewis Pair Chemistry to Alkylamines Enables Broad Scope Reductive Aminations
Fasano, Valerio,Ingleson, Michael J.
supporting information, p. 2217 - 2224 (2017/02/18)
Lower Lewis acidity boranes demonstrate greater tolerance to combinations of water/strong Br?nsted bases than B(C6F5)3, this enables Si?H bond activation by a frustrated Lewis pair (FLP) mechanism to proceed in the presence of H2O/alkylamines. Specifically, BPh3has improved water tolerance in the presence of alkylamines as the Br?nsted acidic adduct H2O–BPh3does not undergo irreversible deprotonation with aliphatic amines in contrast to H2O–B(C6F5)3. Therefore BPh3is a catalyst for the reductive amination of aldehydes and ketones with alkylamines using silanes as reductants. A range of amines inaccessible using B(C6F5)3as catalyst, were accessible by reductive amination catalysed by BPh3via an operationally simple methodology requiring no purification of BPh3or reagents/solvent. BPh3has a complementary reductive amination scope to B(C6F5)3with the former not an effective catalyst for the reductive amination of arylamines, while the latter is not an effective catalyst for the reductive amination of alkylamines. This disparity is due to the different pKavalues of the water–borane adducts and the greater susceptibility of BPh3species towards protodeboronation. An understanding of the deactivation processes occurring using B(C6F5)3and BPh3as reductive amination catalysts led to the identification of a third triarylborane, B(3,5-Cl2C6H3)3, that has a broader substrate scope being able to catalyse the reductive amination of both aryl and alkyl amines with carbonyls.
Ruthenium-Catalyzed Selective Hydroboration of Nitriles and Imines
Kaithal, Akash,Chatterjee, Basujit,Gunanathan, Chidambaram
, p. 11153 - 11163 (2016/11/28)
Ruthenium-catalyzed hydroboration of nitriles and imines is attained using pinacolborane with unprecedented catalytic efficiency. Chemoselective hydroboration of nitriles over esters is also demonstrated. A simple [Ru(p-cymene)Cl2]2 complex (1) is used as a catalyst precursor, which upon reaction with pinacolborane in situ generates the monohydrido-bridged complex [{(η6-p-cymene)RuCl}2(μ-H-μ-Cl)] 2. Further oxidative addition of pinacolborane to intermediate 2 leading to the formation of mononuclear ruthenium hydride species is suggested. Mass spectral analysis of the reaction mixture and independent experiments with phosphine-ligated ruthenium complexes indicated the involvement of mononuclear ruthenium intermediates in the catalytic cycle. Consecutive intramolecular 1,3-hydride transfers from the ruthenium center to coordinated nitrile and boronate imine ligands, leading to the reduction and resulting in the formation of diboronate amines, are proposed as a plausible reaction mechanism.
