General asymmetric synthesis of isoquinoline alkaloids. Enantioselective hydrogenation of enamides catalyzed by BINAP-ruthenium(II) complexes

Kitamura, Masato; Hsiao, Yi; Ohta, Masako; Tsukamoto, Masaki; Ohta, Tetsuo; Takaya, Hidemasa; Noyori, Ryoji

doi:10.1021/jo00081a007

Cited by 145 publications

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“…1,2 Ru(OCOCH 3 ) 2 (binap) 18 catalyzes highly enantioselective hydrogenation of a variety of olefinic substrates such as enamides, a,b-and b,g-unsaturated carboxylic acids, and allylic and homoallylic alcohols (Figure 1.9). 6,7,[45][46][47][48] Chiral citronellol is produced in 300 ton quantity in year by this reaction. 9 It is worth noting that an opposite sense of enantioface selection is observed in going from the BINAP-Rh complex to the Ru catalyst.…”

Section: Hydrogenation Of Functionalized Olefins With Ruthenium Catalmentioning

confidence: 99%

Ligand Design for Catalytic Asymmetric Reduction

Ohkuma¹,

Kitamura²,

Noyori³

2006

New Frontiers in Asymmetric Catalysis

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Section: Hydrogenation Of Functionalized Olefins With Ruthenium Catalmentioning

confidence: 99%

Ligand Design for Catalytic Asymmetric Reduction

Ohkuma¹,

Kitamura²,

Noyori³

2006

New Frontiers in Asymmetric Catalysis

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“…Using this catalyst system, isoquinoline alkaloids, morphine, and its artificial analogues can be prepared in an enantiopure form. A representative example, the synthesis of (S)-tetrahydropapaverine, is shown in Scheme 13 [39].…”

Section: Scheme 12 Asymmetric Hydrogenation Of Geraniol and Nerol Wimentioning

confidence: 99%

Asymmetric Hydrogenation

2011

Homogeneous Catalysts

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“…5) (6, 7). For example, the reaction with N-acylated benzylidene-tetrahydroisoquinolines gives chiral benzyl-tetrahydroisoquinolines such as N-protected tetrahydropapaverine (13) in near 100% ee, providing a general method of asymmetric synthesis of isoquinoline alkaloids (23). Hydrogenation of geraniol possessing two olefinic bonds occurs only at the allylic alcohol part, thereby affording citronellol (14) in Ͼ95% ee (24).…”

Section: Metallic Elements: Rhodium Vs Ruthenium In Asymmetric Hydromentioning

confidence: 99%

Toward Efficient Asymmetric Hydrogenation: Architectural and Functional Engineering of Chiral Molecular Catalysts

2004

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Asymmetric hydrogenation uses inexpensive, clean hydrogen gas and a very small amount of a chiral molecular catalyst, providing the most powerful way to produce a wide array of enantio-enriched compounds in a large quantity without forming any waste. The recent revolutionary advances in this field have entirely changed the synthetic approach to producing performance chemicals that require a high degree of structural precision. The means of developing efficient asymmetric hydrogenations is discussed from a mechanistic point of view.A symmetric catalysis lies outside the realm of traditional organic synthesis. It is a pervasive, global endeavor involving synthetic organic chemistry, catalytic chemistry, structural chemistry, inorganic and coordination chemistry, physical chemistry, and theoretical chemistry, as well as chemical engineering. Chiral Molecular Catalysts:Beyond the Shape Asymmetric catalysis is four-dimensional chemistry (1). High efficiency can be achieved only by using a combination of both an ideal 3D structure (x, y, z) and suitable kinetics (t). Currently, efficient asymmetric catalysis primarily uses a molecular catalyst that consists of a metallic element and chiral organic ligand(s) (2). Fig. 1 illustrates a typical (but not general) catalytic scheme. Under reaction conditions, the initially used precatalyst 1 is converted to the true catalyst 2 (induction process) that activates achiral molecules A and B and transforms them to the chiral product A-B (catalytic cycle). Although the ligand must create a distinct enantio-differentiating environment in transition metal-based complexes, such an architectural design does not suffice to achieve asymmetric catalysis. Some of the steps in the multistep transformation are reversible, whereas the first irreversible step, for example 334, kinetically determines the absolute stereochemistry of A-B. Efficient asymmetric catalysis requires a high turnover number and high turnover frequency, but the best way to generate high catalytic activity is not immediately apparent. First, the induction process of converting 1 to 2 is often not straightforward. Furthermore, to obtain a high turnover frequency, all of the transition metal-based entities 2-4 in this cycle must be neither very unstable nor very stable, avoiding substrate and͞or product inhibition. Instead, 2-4 are required to interconvert one another smoothly by means of a low kinetic barrier, and without any destructive side reactions. The reaction conditions strongly influence the stability and reactivity of 1-4. In general, both suitable architectural and functional engineering are crucial for obtaining sufficient catalytic efficiency. ''Molecular catalysis'' can cope with such requirements, because any molecules, by definition, can be designed and synthesized at will.This perspective deals largely with the intrinsic mechanistic aspects of asymmetric hydrogenation developed in our laboratories (3-5). Although HOH bonds are readily cleaved by transition metal complexes, truly useful asymmetric hydrogena...

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General asymmetric synthesis of isoquinoline alkaloids. Enantioselective hydrogenation of enamides catalyzed by BINAP-ruthenium(II) complexes

Cited by 145 publications

References 1 publication

Ligand Design for Catalytic Asymmetric Reduction

Ligand Design for Catalytic Asymmetric Reduction

Asymmetric Hydrogenation

Toward Efficient Asymmetric Hydrogenation: Architectural and Functional Engineering of Chiral Molecular Catalysts

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