P,N and Non‐Phosphorus Ligands

Pfaltz, Andreas; Bell, Sharon

doi:10.1002/9783527619382.ch29

Cited by 2 publications

(2 citation statements)

References 58 publications

(46 reference statements)

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“…The discovery of the Crabtree catalyst ([Ir(PCy 3 )(pyridine)(cod)] + [PF 6 ] − ), which exhibits remarkably high activity in the hydrogenation of unfunctionalized alkenes including sterically hindered tetrasubstituted ones, has promoted the development of chiral P,N-ligands for asymmetric hydrogenation . The most successful work in this area was accomplished by Pfaltz with the development of the oxazoline-derived P,N-ligand (PHOX) and with the discovery of the remarkable rate enhancement effect of a bulky and weakly coordinating anion, tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BArF). − This methodology has been further greatly developed with the significant expansion of the substrate scope and catalytic efficiency. − Various P-stereogenic P,N-ligands have also been employed in the asymmetric hydrogenation of prochiral alkenes, imines, and related substrates.…”

Section: Applications Of P-stereogenic Phosphorus Ligands In Asymmetr...mentioning

confidence: 99%

P-Stereogenic Phosphorus Ligands in Asymmetric Catalysis

Imamoto

2024

Chem. Rev.

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Chiral phosphorus ligands play a crucial role in asymmetric catalysis for the efficient synthesis of useful optically active compounds. They are largely categorized into two classes: backbone chirality ligands and P-stereogenic phosphorus ligands. Most of the reported ligands belong to the former class. Privileged ones such as BINAP and DuPhos are frequently employed in a wide range of catalytic asymmetric transformations. In contrast, the latter class of P-stereogenic phosphorus ligands has remained a small family for many years mainly because of their synthetic difficulty. The late 1990s saw the emergence of novel P-stereogenic phosphorus ligands with their superior enantioinduction ability in Rh-catalyzed asymmetric hydrogenation reactions. Since then, numerous P-stereogenic phosphorus ligands have been synthesized and used in catalytic asymmetric reactions. This Review summarizes P-stereogenic phosphorus ligands reported thus far, including their stereochemical and electronic properties that afford high to excellent enantioselectivities. Examples of reactions that use this class of ligands are described together with their applications in the construction of key intermediates for the synthesis of optically active natural products and therapeutic agents. The literature covered dates back to 1968 up until December 2023, centering on studies published in the late 1990s and later years.

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Section: Applications Of P-stereogenic Phosphorus Ligands In Asymmetr...mentioning

confidence: 99%

P-Stereogenic Phosphorus Ligands in Asymmetric Catalysis

Imamoto

2024

Chem. Rev.

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“…2) [60]. The last step is the reduction to methane which in itself involves four protein components (only one of which has been purified): Mg 2~, ATP, FAD, F420 (a deazaflavin derivative) [611, F430 (a nickel tetrapyrrole) [62] and an unidentified component B. Clearly, this portion of the scheme of Fig.…”

Section: Thermoautotrophicummentioning

confidence: 99%

The acetyl-CoA pathway of autotrophic growth

Wood

Ragsdale

Pezacka

1986

FEMS Microbiology Letters

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The most direct conceivable route for synthesis of multicarbon compounds from CO: is to join two molecules of CO 2 together to make a 2-carbon compound and then polymerize the 2-carbon compound or add CO 2 successively to the 2-carbon compound to make multicarbon compounds. Recently, it has been demonstrated that the bacterium, Clostridium thermoaceticum, grows autotrophically by such a process. The mechanism involves the reduction of one molecule of CO 2 to a methyl group and then its combination with a second molecule of CO2 and CoA to form acetyl-CoA. We have designated this autotrophic pathway the acetyl-CoA pathway [1]. Evidence is accumulating that this pathway is utilized by other bacteria that grow with CO 2 and H 2 as the source of carbon and energy. This group includes bacteria which, like C. thermoaceticum, produce acetate as a major end product and are called acetogens or acetogenic bacteria. It also includes the methaneproducing bacteria and sulfate-reducing bacteria.The purpose of this review is to examine critically the evidence that the acetyl-CoA pathway occurs in other bacteria by a mechanism that is the same or similar to that found in C. thermoaceticum. For this purpose, the mechanism of the acetyl-CoA pathway, as found in C. thermoaceticum, is described and hypothetical mecha-nims for other organisms are presented based on the acetyl-CoA pathway of C. thermoaceticum. The available data have been reviewed to determine if the hypothetical schemes are in accord with presently known facts. We conclude that the formation of acetyl-CoA by other acetogens, the methanogens and sulphate-reducing bacteria occurs by a mechanism very similar to that of C.therrnoaceticum.

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P,N and Non‐Phosphorus Ligands

Cited by 2 publications

References 58 publications

P-Stereogenic Phosphorus Ligands in Asymmetric Catalysis

P-Stereogenic Phosphorus Ligands in Asymmetric Catalysis

The acetyl-CoA pathway of autotrophic growth

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