Mechanism of catalytic asymmetric hydrogenation of 2-formyl-1-methylene-1,2,3,4-tetrahydroisoquinoline using Ru(CH3COO)2[(S)-binap]

Tsukamoto, Masaki; Yoshimura, Masahiro; Tsuda, Kazuomi; Kitamura, Masato

doi:10.1016/j.tet.2006.03.055

Cited by 10 publications

(3 citation statements)

References 27 publications

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“…This is in line with the absence in the reduction process of any interference of transfer hydrogenation as well as of protonolysis of the Rh-C bond of an alkyl rhodium intermediate. 21 Two facets deserving mention are (1) the Z-isomer gives higher ee's than the E-isomer, whereas in most cases the opposite behaviour has been reported 3 and (2) the configuration switches depending on the different geometry of the double bond, which has been scarcely reported. 3c,22 Next, we investigated the influence of temperature on enantioselectivity and conversion as shown in Figure 2.…”

Section: Resultsmentioning

confidence: 99%

Development of Practical Rhodium Phosphine Catalysts for the Hydrogenation of β-Dehydroamino Acid Derivatives

Enthaler¹,

Erre²,

Holz³

et al. 2006

Org. Process Res. Dev.

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The rhodium-catalyzed asymmetric hydrogenation of various β-dehydroamino acid derivatives to give optically active β-amino acids has been examined. Chiral monodentate 4,5-dihydro-3Hdinaphthophosphepines, which are easily tuned and accessible in a multi-10-g scale, have been used as ligands. The enantioselectivity is largely dependent on the nature of the substituent at the phosphorous atom and on the structure of the substrate. Applying optimized conditions up to 94% ee was achieved.

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Section: Resultsmentioning

confidence: 99%

Development of Practical Rhodium Phosphine Catalysts for the Hydrogenation of β-Dehydroamino Acid Derivatives

Enthaler¹,

Erre²,

Holz³

et al. 2006

Org. Process Res. Dev.

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“…[1] To date, synthetic efforts have focused on introducing chirality at the C1 position with configurational integrity by employing the following synthetic methodologies: [2] 1) the formation of the six-membered ring through a Bischler-Napieralski cyclization/reduction [3] or a Pictet-Spengler reaction, [4] 2) the C 1 -C a connectivity approach by attaching nucleophilic or electrophilic carbon units to the C1 position of tetrahydroisoquinoline derivatives, [5] and 3) the asymmetric hydrogenation of alkylidene-1,2,3,4-tetrahydroisoquinoline derivatives. [6] However, these methods have some limitations, such as a limited substrate scope and the need for stoichiometric amounts of a chiral auxiliary. In contrast to 1substituted THIQs, the synthesis of 3-substituted THIQs has rarely been achieved, [7] although their unique structural and diverse biologic properties have been noted.…”

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confidence: 99%

Asymmetric Hydrogenation of Isoquinolinium Salts Catalyzed by Chiral Iridium Complexes: Direct Synthesis for Optically Active 1,2,3,4‐Tetrahydroisoquinolines

et al. 2013

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,4-Tetrahydroisoquinolines (THIQs), a class of highly important molecular skeletons abundant in natural alkaloids and biologically active compounds, are often used as key intermediates for the synthesis of pharmaceutical drugs and drug candidates.[1] To date, synthetic efforts have focused on introducing chirality at the C1 position with configurational integrity by employing the following synthetic methodologies:[2] 1) the formation of the six-membered ring through a Bischler-Napieralski cyclization/reduction [3] or a PictetSpengler reaction, [4] 2) the C 1 -C a connectivity approach by attaching nucleophilic or electrophilic carbon units to the C1 position of tetrahydroisoquinoline derivatives, [5] and 3) the asymmetric hydrogenation of alkylidene-1,2,3,4-tetrahydroisoquinoline derivatives.[6] However, these methods have some limitations, such as a limited substrate scope and the need for stoichiometric amounts of a chiral auxiliary. In contrast to 1-substituted THIQs, the synthesis of 3-substituted THIQs has rarely been achieved, [7] although their unique structural and diverse biologic properties have been noted.[8] Accordingly, the development of more general and straightforward synthetic methods toward 1-and 3-substituted THIQs is in high demand. Although asymmetric hydrogenation of substituted isoquinolines is considered the most attractive and straightforward synthetic protocol, isoquinoline is regarded as the most challenging substrate in asymmetric hydrogenation. An efficient catalytic system has not even been found for the reduction of isoquinolines in a nonenantioselective manner. [9] Nonetheless, the recent development of an asymmetric hydrogenation of aromatic and heteroaromatic compounds was remarkable, [10][11][12][13][14][15][16][17][18][19][20] and Zhou and co-workers reported the catalytic asymmetric hydrogenation of isoquinolines, although the substrate scope is limited and an activating reagent is sometimes required (Scheme 1). [21] As part of our continuing interest in the asymmetric hydrogenation of N-heteroaromatic compounds using halogen-bridged dinuclear iridium(III) complexes, [22] we previously reported the additive effect of aryl amine derivatives in the asymmetric hydrogenation of quinoxalines, [22d] where the addition of more-basic aliphatic amines retarded the reaction, presumably because of their tight coordination to the iridium center. These findings strongly suggested that the difficulties of catalytic hydrogenation of isoquinolines upon catalysis by iridium complexes might be due to the strong basicity of the corresponding THIQs. This hypothesis prompted us to study the asymmetric hydrogenation of isoquinolinium chlorides to give the corresponding tetrahydroisoquinolinium chlorides, thus avoiding the deactivation of the iridium catalyst and providing a direct transformation of isoquinolines to THIQs in an enantioselective manner by a simple basic workup (Scheme 1).We first examined the asymmetric hydrogenation of the 3-phenylisoquinolinium salt 2 a-HCl with H 2 (30 bar) and ...

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“…The overall rate is limited by the hydrogenolysis step. 333 Ferrocene-based aminophosphines are shown to be effective ligands in the Ru(II)ee catalysed asymmetric hydrogenation of ketones. The enantioselectivity is mainly determined by the C-centred chirality of the ligands, but the planar chirality is also important, and (R C ,S Fc )-or (S C ,R Fc )-is the matched combination of chiralities.…”

Section: Hydrogenationmentioning

confidence: 99%

Oxidation and Reduction

Banerji¹

2010

Organic Reaction Mechanisms · 2006

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Mechanism of catalytic asymmetric hydrogenation of 2-formyl-1-methylene-1,2,3,4-tetrahydroisoquinoline using Ru(CH3COO)2[(S)-binap]

Cited by 10 publications

References 27 publications

Development of Practical Rhodium Phosphine Catalysts for the Hydrogenation of β-Dehydroamino Acid Derivatives

Development of Practical Rhodium Phosphine Catalysts for the Hydrogenation of β-Dehydroamino Acid Derivatives

Asymmetric Hydrogenation of Isoquinolinium Salts Catalyzed by Chiral Iridium Complexes: Direct Synthesis for Optically Active 1,2,3,4‐Tetrahydroisoquinolines

Oxidation and Reduction

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