87861-38-9Relevant academic research and scientific papers
Continuous Flow Chiral Amine Racemization Applied to Continuously Recirculating Dynamic Diastereomeric Crystallizations
Kwan, Maria H. T.,Breen, Jessica,Bowden, Martin,Conway, Louis,Crossley, Ben,Jones, Martin F.,Munday, Rachel,Pokar, Nisha P. B.,Screen, Thomas,Blacker, A. John
, p. 2458 - 2473 (2021/02/06)
A new, dynamic diastereomeric crystallization method has been developed, in which the mother liquors are continuously separated, racemized over a fixed-bed catalyst, and recirculated to the crystallizer in a resolution-racemization-recycle (R3) process. S
Deactivation mechanisms of iodo-iridium catalysts in chiral amine racemization
Kwan, Maria H.T.,Pokar, Nisha P.B.,Good, Catherine,Jones, Martin F.,Munday, Rachel,Screen, Thomas,Blacker, A. John
supporting information, (2020/12/29)
The homogenous, [IrCp?I2]2, SCRAM catalyst (1) is active in the racemization of chiral amines. NMR, kinetic and structural mechanistic studies have determined the cause of catalyst deactivation to occur when ammonia or methylamine are liberated by hydrolysis or aminolysis of the intermediate imine, which tightly coordinate to the iridium centre to block turnover. Control of moisture and substrate concentration can suppress deactivation, whilst partial reactivation of spent catalyst was identified using hydroiodic acid.
Enantioselective reduction of: N -alkyl ketimines with frustrated Lewis pair catalysis using chiral borenium ions
Mercea, Dan M.,Howlett, Michael G.,Piascik, Adam D.,Scott, Daniel J.,Steven, Alan,Ashley, Andrew E.,Fuchter, Matthew J.
supporting information, p. 7077 - 7080 (2019/06/20)
Enantioselective reduction of ketimines was demonstrated using chiral N-heterocyclic carbene (NHC)-stabilised borenium ions in frustrated Lewis pair catalysis. High levels of enantioselectivity were achieved for substrates featuring secondary N-alkyl substituents. Comparative reactivity and mechanistic studies identify key determinants required to achieve useful enantioselectivity and represent a step forward in the further development of enantioselective FLP methodologies.
Efficient, selective, and green: Catalyst tuning for highly enatioselective reactions of ethylene
Smith, Craig R.,Rajanbabu
supporting information; experimental part, p. 1657 - 1659 (2009/04/10)
Fine tuning of the biaryl and amino moieties of Feringa's phosphoramidite ligands yields structurally simpler, yet more efficient and selective, ligands for asymmetric hydrovinylation of vinylarenes and acylic 1,3-dienes. The enantioselectivities and yields observed in the formation of the 3-arylbutenes are among the highest for all asymmetric catalytic processes reported to date for the synthesis of intermediates for the widely used antiinflammatory 2-arylpropionic acids including naproxen, ibuprofen, fenoprofen, and flurbiprofen.
CHIRAL COMPOUND SUITABLE AS A CATALYST FOR ASYMMETRIC TRANSFER HYDROGENATION
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Page/Page column 24, (2010/11/30)
The invention relates to an enantiomerically enriched chiral compound comprising a transition metal M, which comprises four, five or six coordinating groups of which at least one pair is linked together to form a bidentate ligand, in which M is directly bound via one single ?-bond to a carbon atom of an optionally substituted and/or optionally fused (hetero)aromatic ring of said bidentate ligand and in which M is directly bound to a nitrogen atom of a primary or secondary amino group of said bidentate ligand, thereby forming a metallacycle between said bidentate ligand and the metal M, said metal M being selected from the metals of groups 8 and 9 of the Periodic Table of the Elements, in particular iron, ruthenium, osmium, cobalt, rhodium, or iridium. The chiral compound can be used as a catalyst, preferably in an asymmetric transfer hydrogenation process. The invention further relates to a process for an asymmetric transfer hydrogenation of a prochiral compound in the presence of a hydrogen donor and the chiral compound of the invention comprising a transition metal chosen from the metals of groups 8, 9 and 10 of the Periodic Table, in particular iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium or platinum as the catalyst.
Enantioselective conjugate addition to cyclic enones with scalemic lithium organo(amido)cuprates, part IV. Relationship between ligand structure and enantioselectivity
Rossiter, Bryant E.,Eguchi, Masakatsu,Miao, Guobin,Swingle, Nicole M.,Hernandez, Amelia E.,Vickers, Denise,Fluckiger, Ezdan,Greg Patterson,Vasavi Reddy
, p. 965 - 986 (2007/10/02)
Scalemic lithium amides derived from primary and secondary amines react with organocopper compounds in ether or dimethyl sulfide to form lithium organo(amido)cuprates capable of enantioselective conjugate addition to 2-cycloalkenones. The most successful heterocuprate, in which the chiral ligand is (S)-N-methyl-1-phenyl-2-(1-piperidinyl)ethanamine, (S)-MAPP, 13, reacts with cyclic enones to form products with up to 97% ee. Nonlinear asymmetric induction was observed with the cuprate formed from ligand 13.
Use of N,N'-dimethylpropyleneurea (DMPU) as solvent in the efficient preparation of enantiomerically pure secondary amines
Juaristi,Murer,Seebach
, p. 1243 - 1246 (2007/10/02)
The monoalkylation of (R)- and (S)-1-phenylethylamine proceeds readily with DMPU as the solvent. An efficient procedure was then developed for the high-yield preparation of the chiral secondary amines N-benzyl-, N-isopropyl-, N-(2-biphenylyl)methyl-, N-(diphenyl)methyl-, and N-(2,2-dimethyl)propyl-1-phenylethylamine, in enantiomerically pure form.
ASYMMETRIC DEPROTONATION OF PROCHIRAL KETONES USING CHIRAL LITHIUM AMIDE BASES
Cain, Christian M.,Cousins, Richard P. C.,Coumbarides, Greg,Simpkins, Nigel S.
, p. 523 - 544 (2007/10/02)
A number of chiral secondary amines have been prepared and used as precursors to the corresponding chiral lithium amide bases.Treatment of either cis-2,6-dimethylcyclohexanone or 4-tert-butylcyclohexanone with a chiral lithium amide, followed by electrophilic quench, gives chiral products in up to 88 percent enantiomeric excess.The results with 4-tert-butylcyclohexanone are in disagreement with an earlier literature report, giving products of lower enantiomeric excess but higher optical rotation.
Asymmetric Synthesis of Mellein Methyl Ether: Use of ortho-Toluate Carbanions Generated by Chiral Bases
Regan, Andrew C.,Staunton, James
, p. 764 - 765 (2007/10/02)
An ortho-toluate carbanion generated from (2) by the chiral lithium amide base (6), (7), or (11) undergoes an enantioselective aldol-type reaction with acetaldehyde to give mellein methyl ether (3), in up to 53 percent enantiomeric excess.
