5269-05-6Relevant academic research and scientific papers
NOVEL CATALYSTS
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Page/Page column 69, (2012/06/01)
The present invention provides novel compounds and ligands that are useful in transition metal catalyzed cross-coupling reactions. For example, the compounds and ligands of the present invention are useful in palladium or gold catalyzed cross-coupling reactions.
A highly versatile catalyst system for the cross-coupling of aryl chlorides and Amines
Lundgren, Rylan J.,Sappong-Kumankumah, Antonia,Stradiotto, Mark
supporting information; experimental part, p. 1983 - 1991 (2010/07/03)
The syntheses of 2-(di-tertbutylphosphino)-N,N-dimethylaniline (L1, 71%) and 2-(di-1-adamantylphosphino)-N,N-dimethylaniline (L2, 74%), and their application in BuchwaldHartwig amination, are reported. In combination with [Pd(allyl)Cl]2 or [Pd(cinnamyl)Cl]2, these structurally simple and air-stable P,N ligands enable the cross-coupling of aryl and heteroaryl chlorides, including those bearing as substituents enolizable ketones, ethers, esters, carboxylic acids, phenols, alcohols, olefins, amides, and halogens, to a diverse range of amine and related substrates that includes primary alkyl- and arylamines, cyclic and acyclic secondary amines, N-H imines, hydrazones, lithium amide, and ammonia. In many cases, the reactions can be performed at low catalyst loadings (0.5-0.02 mol % Pd) with excellent functional group tolerance and chemoselectivity. Examples of cross-coupling reactions involving 1,4-bromochlorobenzene and iodobenzene are also reported. Under similar conditions, inferior catalytic performance was achieved when using Pd(OAc)2, PdCl2, [PdCl2(cod)] (cod = 1,5-cyclooctadiene), [PdCl 2(MeCN)2], or [Pd2(dba)3] (dba = dibenzylideneacetone) in combination with L1 or L2, or by use of [Pd(allyl)Cl]2 or [Pd(cinnamyl)Cl]2 with variants of L1 and L2 bearing less basic or less sterically demanding substituents on phosphorus or lacking an ortto-dimethylamino fragment. Given current limitations associated with established ligand classes with regard to maintaining high activity across the diverse possible range of C-N coupling applications, L1 and L2 represent unusually versatile ligand systems for the cross-coupling of aryl chlorides and amines
Highly reactive, general and long-lived catalysts for palladium-catalyzed amination of heteroaryl and aryl chlorides, bromides, and iodides: Scope and structure-activity relationships
Shen, Qilong,Ogata, Tokutaro,Hartwig, John F.
, p. 6586 - 6596 (2008/12/22)
We describe a systematic study of the scope and relationship between ligand structure and activity for a highly efficient and selective class of catalysts containing sterically hindered chelating alkylphosphines for the amination of heteroaryl and aryl chlorides, bromides, and iodides. In the presence of this catalyst, aryl and heteroaryl chlorides, bromides, and iodides react with many primary amines in high yields with part-per-million quantities of palladium precursor and ligand. Many reactions of primary amines with both heteroaryl and aryl chlorides, bromides, and iodides occur to completion with 0.0005-0.05 mol % catalyst. A comparison of the reactivity of this catalyst for the coupling of primary amines at these loadings is made with catalysts generated from hindered monophosphines and carbenes, and these data illustrate the benefits of chelation. Studies on structural variants of the most active catalyst indicate that a rigid backbone in the bidentate structure, strong electron donation, and severe hindrance all contribute to its high reactivity. Thus, these complexes constitute a fourth-generation catalyst for the amination of aryl halides, whose activity complements catalysts based on monophosphines and carbenes.
Process for preparing 3-(N,N-disubstituted amino)phenol
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, (2008/06/13)
A process for preparing a 3-(N,N-disubstituted amino)phenol is herein disclosed which comprises reacting resorcin with a primary amine represented by formula (2): wherein R1 is an alkyl group, a cycloalkyl group, an alkenyl group, an alkoxyalkyl group, an aryl group or an aralkyl group, terminating the reaction when the conversion of resorcin is 50 mol % or more and when the amount of an N,N'-disubstituted-m-phenylenediamine as a by-product is 2 mol % or less of the amount of used resorcin, adding an alkyl halide represented by formula (3): wherein R2 is an alkyl group or a cycloalkyl group; and X is a halogen atom, to the obtained reaction mixture, adding an aqueous alkaline solution to the resultant reaction mixture to dissolve unreacted resorcin in the aqueous phase, extracting the 3-(N,N-disubstituted amino)phenol with an organic solvent, and then recovering unreacted resorcin from the aqueous phase. According to this process, the high-purity 3-(N,N-disubstituted amino)phenol can be prepared from resorcin in a substantially high yield, the production of by-products being inhibited.
Process for preparing N-alkylaminophenols
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, (2008/06/13)
A process for preparing an N-alkylaminophenol is disclosed, comprising subjecting an aminophenol to reductive alkylation with an aldehyde or a ketone in the presence of an organic solvent and hydrogen, wherein the reductive alkylation is carried out at a temperature of from 20° to 70° C. in the further presence of a catalyst for reduction comprising platinum and at least one metal element selected from metal elements belonging to the IB group, IIB group, IVB group, VB group, and VIB group of the Periodic Table, supported on activated carbon, or comprising palladium and at least one metal element selected from metal elements belonging to the IB group, IIB group, IVB group, VB group and VIB group of the Periodic Table, supported on activated carbon.
