21307-97-1Relevant academic research and scientific papers
Modular 1,1′-Ferrocenediyl-cored P-Stereogenic Diphosphines: ′′JDayPhos′′ Series and its Use in Rhodium(I)-Catalyzed Hydrogenation
Poklukar, Ga?per,Stephan, Michel,Mohar, Barbara
, p. 2566 - 2570 (2018/05/16)
A novel ferrocene-based P-stereogenic diphospine ligand series dubbed JDayPhos was developed, which rhodium(I) complexes of some of its members exhibited excellent enantioselectivity (up to >99% ee) and high activity in asymmetric hydrogenation of β-unsubstituted or -substituted itaconates and α-methylene-γ-oxo-carboxylates. (Figure presented.).
Identification, synthesis and characterization of impurities of (S)-Mitiglinide calcium dihydrate
Umasankara Sastry,Nageswara Rao,Appi Reddy,Gandhi
, p. 2417 - 2421 (2014/06/09)
(S)-Mitiglinide Calcium dihydrate (1), an important potent hypoglycemic agent. During laboratory optimization and later in bulk synthesis the formation of various impurities was observed. The method of preparation of most of these impurities is not availa
A facile chemoenzymatic approach to chiral non-racemic β-alkyl-γ-amino acids and 2-alkylsuccinic acids. A concise synthesis of (S)-(+)-Pregabalin
Felluga, Fulvia,Pitacco, Giuliana,Valentin, Ennio,Venneri, Cesare Daniele
, p. 945 - 955 (2008/09/21)
Both enantiomerically pure antipodes of GABA analogues were prepared as hydrochloride salts, by enzymatic kinetic resolution of their precursors ethyl 2-(nitromethyl)alkanoates. These latter compounds can be easily transformed into enantiomerically pure 2-alkylsuccinic acids by a Nef reaction followed by oxidation. Interestingly, this reaction was particularly easy for the neopentyl derivative (S)-(+)-7d, which underwent conversion into its corresponding succinic acid derivative (S)-(-)-8d in buffered solution. The absolute configurations of the main compounds of interest involved are given, together with their CD spectra.
Synthesis and application of phosphinoferrocenylaminophosphine ligands for asymmetric catalysis
Boaz, Neil W.,Mackenzie, Elaine B.,Debenham, Sheryl D.,Large, Shannon E.,Ponasik Jr., James A.
, p. 1872 - 1880 (2007/10/03)
(Chemical Equation Presented) A new class of bidentate ligands utilizing a phosphine-aminophosphine structure has been prepared on a ferrocenylethyl backbone in a straightforward and scalable fashion from acetylferrocene. The unique property of the α-ferrocenyl carbonium ion that allows the replacement of a variety of "leaving groups" with retention of configuration greatly facilitates the synthesis, and a number of ligands have been prepared by varying the nitrogen and phosphorus substituents on the aminophosphine. These readily prepared phosphinoferrocenylaminophosphines, known as BoPhoz ligands, show surprising hydrolytic and air stability, with no degradation after 3 years open to the air. The rhodium complexes of these ligands show exceedingly high enantioselectivities (generally > 95% ee) and activities often in excess of 50 000 catalyst turnovers per hour for the asymmetric hydrogenation of a wide variety of dehydro-α-amino acid and itaconic acid derivatives. They also show high activity and good to excellent enantioselectivity for the hydrogenation of a number of α-ketoesters.
Diastereoselective conjugate addition of Grignard reagents to a homochiral fumaramide derived from Oppolzer's sultam
Reid, Gary P.,Brear, Kieron W.,Robins, David J.
, p. 793 - 801 (2007/10/03)
Conjugate addition of Grignard reagents to N,N′-fumaroylbis[(2R)- bornane-10,2-sultam] 1 occurred with moderate to high levels of diastereoselectivity. Diastereomeric excesses were estimated by analysis of the 1H NMR spectra of the succinamide mixtures and enantiomeric excesses from 19F NMR spectra of the bis Mosher esters of the diols produced by reductive cleavage of the succinamides. Saponification of the succinamides gave the corresponding (R)-succinic acids with ees up to 92% showing that addition of the Grignard reagents takes place selectively on the re-face of 1.
Preparation of (R)-(-)- and (S)-(+)-3-hydroxymethyl-1-tetralone tosylates, key intermediates in the synthesis of new CNS drugs, via resolution of precursors
Caro, Yolanda,Masaguer, Christian F.,Ravina, Enrique
, p. 381 - 387 (2007/10/03)
The preparation of (R)-(-)- and (S)-(+)-3-hydroxymethyl-1-tetralone tosylates, key intermediates in the synthesis of new CNS drugs in the aminobutyrophenone family, has been developed via classical resolutions or lipase-catalyzed kinetic resolution of one of their precursors.
Phosphinoferrocenylaminophosphines as novel and practical ligands for asymmetric catalysis
Boaz, Neil W.,Debenham, Sheryl D.,Mackenzie, Elaine B.,Large, Shannon E.
, p. 2421 - 2424 (2007/10/03)
(Matrix Presented) A new series of ligands with a novel phosphine-aminophosphine ligation design as depicted in structure 1 has been prepared on a ferrocenylethyl backbone. These BoPhoz ligands of structure 2 have afforded exceedingly high activity and enantioselectivity in the rhodium-catalyzed asymmetric hydrogenation of dehydro-α-amino acid derivatives, itaconic acids, and α-ketoesters. These air-stable ligands are readily prepared from cost-effective and non-pyrophoric intermediates.
A new methodology for the synthesis of β-amino acids
Sibi, Mukund P.,Deshpande, Prasad K.
, p. 1461 - 1466 (2007/10/03)
A differentially functionalized succinic acid unit 6 undergoes alkylation with excellent regio- and high stereocontrol at the carbon α to the imide to furnish the alkylated product 7 in 60-83% yield. Selective removal of the imide provides 8 in 80-90% yie
Stereochemistry in enzyme inhibition: Synthesis and evaluation of enantiomerically pure 2-benzyl-3-formylpropanoic acids as inhibitors of carboxypeptidase A
Kim, Dong H.,Chung, Suhman
, p. 3769 - 3776 (2007/10/03)
Both enantiomers of 2-benzyl-3-formylpropanoic acid were synthesized in five steps starting with hydrocinnamic acid and each enantiomer assayed for inhibitory activity against carboxypeptidase A to find that the (R)-form is 674-fold more potent than its e
