281214-25-3Relevant academic research and scientific papers
Betti's base for crystallization-induced deracemization of substituted aldehydes: synthesis of enantiopure amorolfine and fenpropimorph
Carella, Andrea,Ramos Ferronatto, Gabriel,Marotta, Emanuela,Mazzanti, Andrea,Righi, Paolo,Paolucci, Claudio
, p. 2968 - 2978 (2017/04/10)
The acid-promoted crystallization-induced diastereoisomer transformation (CIDT) of naphthoxazines derived from racemic O-protected 2-substituted 4-hydroxybutyraldehydes and enantiopure Betti's base allows the deracemization of the starting aldehydes with ee up to 96%. As an alternative, reduction with lithium aluminum hydride of the diastereoisomerically enriched naphthoxazines leads to enantioenriched primary amines. The utility of the latter strategy was demonstrated by applying it to the synthesis of enantioenriched fenpropimorph and to the first synthesis of enantiopure amorolfine, with ee up to 99.5%.
Direct regiospecific and highly enantioselective intermolecular α-allylic alkylation of aldehydes by a combination of transition-metal and chiral amine catalysts
Afewerki, Samson,Ibrahem, Ismail,Rydfjord, Jonas,Breistein, Palle,Cordova, Armando
supporting information; experimental part, p. 2972 - 2977 (2012/04/11)
The first direct intermolecular regiospecific and highly enantioselective α-allylic alkylation of linear aldehydes by a combination of achiral bench-stable Pd0 complexes and simple chiral amines as co-catalysts is disclosed. The co-catalytic asymmetric chemoselective and regiospecific α-allylic alkylation reaction is linked in tandem with in situ reduction to give the corresponding 2-alkyl alcohols with high enantiomeric ratios (up to 98:2 e.r.; e.r.=enantiomeric ratio). It is also an expeditious entry to valuable 2-alkyl substituted hemiacetals, 2-alkyl-butane-1,4-diols, and amines. The concise co-catalytic asymmetric total syntheses of biologically active natural products (e.g., Arundic acid) are disclosed. Go organic! Direct intermolecular regiospecific and highly enantioselective α-allylic alkylation of linear aldehydes by a combination of achiral bench-stable Pd0 complexes and simple chiral amines as co-catalysts is disclosed (see scheme). Copyright
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.
Concise synthesis of (+)-β-benzyl γ-butyrolactones from butynediol
Kamlage,Sefkow,Zimmermann,Peter
, p. 77 - 80 (2007/10/03)
The synthesis of optically active β-benzyl-γ-butyrolactones from butynediol via four transition metal catalysed reactions is reported. Key reactions are the hitherto unknown enantioselective hydrogenation of 2-benzyl-2-buten-1,4-diols using Ir(I) phosphinooxazoline catalysts and the regiocontrolled oxidation of the resulting 2-benzyl-1,4-butanediols to the β-substituted butyrolactones.
Asymmetric synthesis of 1,3- and 1,3,4-substituted pyrrolidines
Lin, Jing,Chan, Wing Hong,Lee, Albert W. M.,Wong, Wai Yeung,Huang, Pei Qiang
, p. 2949 - 2951 (2007/10/03)
Diastereoselective alkylation of N-acylnorbornene sultams 2 afforded a variety of enantiomerically pure products 3a-3e. Reduction with LiAlH4 (LAH) followed by ditosylation furnished chiral 1,4-ditosylates 5a-5e which underwent a cyclization reaction with primary amines to afford chiral 1,3- and 1,3,4-substituted pyrrolidines. (C) 2000 Elsevier Science Ltd.
Oxidation of some prochiral 3-substituted cyclobutanones using monooxygenase enzymes: a single-step method for the synthesis of optically enriched 3-substituted γ-lactones
Gagnon, Rene,Grogan, Gideon,Groussain, Esther,Pedragosa-Moreau, Sandrine,Richardson, Paul F.,et al.
, p. 2527 - 2528 (2007/10/02)
Oxidation of the prochiral cyclobutanones 1-5 using Acinetobacter calcoaceticus NCIMB 9871 and Pseudomonas putida NCIMB 10007 monooxygenases (MO1 and MO2) furnishes the corresponding lactones 6-10 in moderate to excellent yield and enantiomeric purity.The
