Efficient asymmetric synthesis of α-amino acids through hydrogenation of α,β-dehydroamino acid residue in cyclic dipeptides

Kanmera, Tatsuhiko; Lee, Sannamu; Aoyagi, Haruhiko; Izumiya, Nobuo

doi:10.1016/s0040-4039(01)86625-9

Cited by 28 publications

(9 citation statements)

References 10 publications

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“…[14] The values for the optical rotation obtained were the same as those reported. [15,16] in acetic anhydride acetic acid (20 mL) was heated at 130°C under argon for 7 h. After evaporation under argon the residue was mixed with saturated aqueous NaHCO 3 (50 mL) and extracted with CHCl 3 (3ϫ50 mL). The organic phase was dried with Na 2 SO 4 and evaporated under vacuum at 50°C to give 3.30 g of crude (S)-1,4-diacetyl-3-methyl-2,5-piperazinedione (R f ϭ 0.6, EtOAc /hexane, 1:1).…”

Section: Methodsmentioning

confidence: 99%

Unusual CC Bond Migration in 3-Ylidene-2,5-piperazinediones

Jin

Wessig

Liebscher³

2000

Eur. J. Org. Chem.

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Section: Methodsmentioning

confidence: 99%

Unusual CC Bond Migration in 3-Ylidene-2,5-piperazinediones

Jin

Wessig

Liebscher³

2000

Eur. J. Org. Chem.

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“…Izumiya and coworkers [27][28][29][30] studied the catalytic hydrogenation over Pd black of dehydrodiketopiperazines obtained from the condensation of several amino acid residues (Fig. 10).…”

Section: References See Page 3661mentioning

confidence: 99%

Diastereoselective Catalysis

Бессон

Pinel

2008

Handbook of Heterogeneous Catalysis

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IntroductionA reaction is referred to as stereoselective when a substrate S, which may yield a series of stereoisomer products (P 1 , P 2 , . . . P n ) gives preferentially -or even exclusively -one of these. Today, the preparation of stereoisomeric compounds is generating tremendous academic and industrial interest. Especially, the synthesis of enantiopure chiral compounds is becoming increasingly important in the production of pharmaceuticals, agrochemicals, fragrances, and flavor substances. Among the different methods used to prepare pure enantiomers, asymmetric catalysis plays an important role, particularly hydrogenation. Currently, two types of asymmetric hydrogenation with solid catalysts are utilized, namely enantioselective and diastereoselective synthesis.In enantioselective hydrogenation, one enantiomer of a chiral product is formed preferentially from a prochiral precursor, the stereoselectivity being induced by a chiral catalyst. Immobilization of very selective metal-ligand complexes and modification of active metals by an adsorbed chiral organic molecule (chiral modifier) have been extensively studied [1]. In some cases, high enantioselectivities approaching 98% enantiomeric excess (e.e.) have been obtained with modified supported metal catalysts. The numerous investigations devoted to the understanding of the mechanism have been summarized in several reviews [1][2][3][4][5]. The most effective catalysts are Ni-tartaric acid, Pt-cinchona, Pd-cinchona and, to a lesser extent, Rh-cinchona systems. The field of reaction types is still limited to a narrow range of asymmetric hydrogenations.The other frequently used catalytic strategy for the synthesis of pure enantiomers is based on diastereoselective hydrogenation. This involves the selective formation of one diastereoisomer by creating a new stereogenic center in a chiral molecule. In this approach, the reaction consists of three simple steps. First, a covalent bond between the prochiral substrate and a chiral moiety (chiral auxiliary) is formed. Then, the diastereoselective hydrogenation is performed over various noble metal catalysts, leading stereoselectively to a new chiral center. This step does not require a chiral catalyst, but the stereogenic center in the chiral auxiliary is able to induce the stereoselectivity. The desired molecule can finally be obtained by selective cleavage of the chiral auxiliary from the product which can be recycled.

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“…The catalytic hydrogenation of dehydrodiketopiperazines containing dehydro-α-aminobutyric acid, dehydrovaline, dehydroleucine, dehydrophenylalanine, dehydro-2-amino-5-phenylpentanoic acid and dehydrotryptophane residues, compounds (47) are studied extensively [94][95][96], Scheme (17). The catalytic hydrogenation of dehydrodiketopiperazines containing dehydro-α-aminobutyric acid, dehydrovaline, dehydroleucine, dehydrophenylalanine, dehydro-2-amino-5-phenylpentanoic acid and dehydrotryptophane residues, compounds (47) are studied extensively [94][95][96], Scheme (17).…”

Section: Hydrogenations Of Dehydroamino Acid Derivatives and Aminesmentioning

confidence: 99%

Heterogeneous Catalytic Asymmetric Hydrogenation of the C=C Bond

Tungler¹,

Sı́pos²,

Háda

2006

COC

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The heterogeneous catalytic asymmetric hydrogenation of the C=C bond resulting in optically active product has been a challenge since decades. Such products can arise in enantio-and in diastereoselective reactions depending on whether the prochiral compound is hydrogenated with a chirally modified catalyst or the substrate itself contains the source of chirality in the form of a chiral moiety. The common step in these reactions is the stereodifferentiating hydrogen uptake on the surface of the metal, first of all on that of the Pd.In our laboratory, experiences were collected in the last two decades for both reaction types. The asymmetric C=C hydrogenation of α,β-unsaturated ketones was studied with modified catalysts in the presence of chiral auxiliaries, like the (S)-proline. The latter turned out to be a diastereoselective reaction. Beside the well-known cinchona alkaloids a vinca alkaloid and diphenyl methyl pyrrolidine methanol also were applied as chiral modifiers. The afforded e.e. (enantiomeric excess) values were in most cases moderate, which could be explained among others with the relatively low reaction rates. In comparison with the Pt/cinchona system, large amount of modifier was necessary for the Pd catalyst, and this resulted in the lower reaction rates.The asymmetric hydrogenation of the C=C bond was studied with optically active dehydroamino acid amides, prolineamides of picolinic, nicotinic and pyrrole acetic acids and pyridoin in diastereoselective reactions. 7 3 8 9 (S,S) and (R,S) aminals 10 11 (2S,4S) and (2R,4S) oxazolidinones + diastereoselective chemo and diastereoselective 12 7 4

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Efficient asymmetric synthesis of α-amino acids through hydrogenation of α,β-dehydroamino acid residue in cyclic dipeptides

Cited by 28 publications

References 10 publications

Unusual CC Bond Migration in 3-Ylidene-2,5-piperazinediones

Unusual CC Bond Migration in 3-Ylidene-2,5-piperazinediones

Diastereoselective Catalysis

Heterogeneous Catalytic Asymmetric Hydrogenation of the C=C Bond

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