Practical Asymmetric Synthesis of (R)-(-)-Carnitine Catalyzed by (2R,4R)-4-(Dicyclohexylphosphino)-2-(di-3,5-xylylphosphinomethyl)-N-methyl-1-pyrrolidinecarboxamide-Rhodium Complex1

Takeda, Hideo; Hosokawa, S.; Aburatani, Masakazu; Achiwa, Kazuo

doi:10.1055/s-1991-20676

Cited by 32 publications

(5 citation statements)

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“…13 C and 31 P NMR spectra were recorded on a Bruker DPX spectrometer at 62.9 and 101.25 MHz, or a Varian Mercury-300 machine at 75.5 and 121.5 MHz, respectively. IR spectroscopic data were measured on an Infinity MI-60 FT-IR spectrometer.…”

Section: Methodsmentioning

confidence: 99%

“…C 30.56, H 5.86; found C 30.58, H 5.60.Reaction of Racemic 3 with 3.8  HCl/EtOAc: Diethyl 2,3-epoxypropylphosphonate (3) (1.00 g, 5.15 mmol) was dissolved at room temperature in 2.7 mL of 3.8  HCl/EtOAc. After disappearance of 3 (TLC) the solvent was evaporated in vacuo (0.1 Torr) and the residue (1.406 g) was analysed by 1 H,13 C, 13 C(apt) and 31 P NMR spectroscopy. This material was chromatographed on a silica gel column with chloroform/methanol (50:1, v/v) to give 12 as a colourless oil (0.684 g, 58%) and various mixtures of 12 and 13, including the most polar fraction of 12 and 13 (33:67) (47 mg).…”

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confidence: 99%

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An Efficient Synthesis of Enantiomeric (S)-Phosphocarnitine

Wróblewski

Hałajewska-Wosik

2002

Eur. J. Org. Chem.

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Section: Methodsmentioning

confidence: 99%

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confidence: 99%

An Efficient Synthesis of Enantiomeric (S)-Phosphocarnitine

Wróblewski

Hałajewska-Wosik

2002

Eur. J. Org. Chem.

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“…After chromatographic separation, removal of protecting groups gave (R)-4-hydroxypyrrolidin-2-one (264a) in 51% yield, which was converted to (R)-(6) and (R)- (7) Asymmetric hydrogenation of both ethyl 4-chloro-3-oxobutanoate (265a) with Ru-BINAP [188] and ethyl 4-(dimethylamino)-3-oxobutanoate (265b) with a range of chiral pyrrolidine-based rhodium catalysts [189,190] affords the corresponding alcohol (266) that can be converted to (R)-(7) [188][189][190] and (R)-norcarnitine (R)-(267) (Scheme 14.72) [189,190]. Highest yields (97%) and enantiomeric excess of 97% were obtained with Ru-BINAP catalyzed reactions, carried out on 100-g scale.…”

Section: B-hydroxy-g-amino Acidsmentioning

confidence: 99%

Synthesis of γ‐Aminobutyric Acid Analogs

Hanrahan

Johnston

2009

Amino Acids, Peptides and Proteins in Organic Chemistry

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“…[28]. An MCCXM-Rh complex catalyzes hydrogenation of the 4-chlorodimethylammonium derivative to yield the alcohol in 85% ee [50].…”

Section: B-keto Estersmentioning

confidence: 99%

Enantioselective Ketone and β‐Keto Ester Hydrogenations (Including Mechanisms)

Ohkuma¹,

Noyori²

2006

The Handbook of Homogeneous Hydrogenation

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Enantioselective hydrogenation of b-keto esters is a well-established procedure to produce chiral b-hydroxy esters in high optical purity [1][2][3][4]. Many important biologically active compounds have been synthesized through this procedure, even on a commercial scale [1][2][3][4]. Ru complexes [5] bearing appropriate chiral phosphine ligands [6][7][8] provide excellent catalytic efficiency for this reaction. Certain chiral Rh catalysts [3,4] and heterogeneous Ni catalysts [9] are also utilized. The recent development of the chiral diphosphine/diamine-Ru catalyst enables rapid and stereoselective hydrogenation of simple ketones without a hetero-atom functionality close to the carbonyl group [2,4]. These enantioselective transformations are summarized in the present chapter. Chiral LigandsIn enantioselective hydrogenation of ketonic substrates, the excellent catalytic performance such as high turnover number (TON), turnover frequency (TOF = -TON h -1 or s -1 ), and enantioselectivity is achievable only when (pre)catalysts are prepared by the appropriate combination of metal species and chiral ligands [6-8, 10, 11]. Stereo-repulsive interaction between substituents of ligands and substrates is normally utilized for the regulation of stereochemistry. The metal and ligand must be carefully selected because of the diversity of substrate structures [1][2][3][4][5]. Chiral diphosphine ligands with a C 2 symmetry (see Fig. 32.1) have played a main role in this respect. Recently, however, various effective C 1 phosphine ligands as well as phosphinite ligands have been developed, the structures of which are illustrated in Figures 32.2 and 32.3, respectively. Chiral amine and imine ligands (Fig. 32.4) are also useful, particularly when they are coupled with a chiral diphosphine ligand in the hydrogenation of simple ketones [2,4,5]. Immobilized BINAPs are detailed in Figure 32.5.

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Practical Asymmetric Synthesis of (R)-(-)-Carnitine Catalyzed by (2R,4R)-4-(Dicyclohexylphosphino)-2-(di-3,5-xylylphosphinomethyl)-N-methyl-1-pyrrolidinecarboxamide-Rhodium Complex¹

Cited by 32 publications

References 0 publications

An Efficient Synthesis of Enantiomeric (S)-Phosphocarnitine

An Efficient Synthesis of Enantiomeric (S)-Phosphocarnitine

Synthesis of γ‐Aminobutyric Acid Analogs

Enantioselective Ketone and β‐Keto Ester Hydrogenations (Including Mechanisms)

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