Iridium-catalyzed asymmetric hydrogenation of olefins using pyridine-phosphinites derived from the chiral pool

Žalubovskis, Raivis; Hörmann, Esther; Pfaltz, Andreas; Moberg, Christina

doi:10.3998/ark.5550190.0009.e07

Cited by 11 publications

(4 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Later, a series of phosphinite-pyridine ligands, related to 31 but with a (−)-menthol moiety at the R 2 position, were prepared. However, these ligands were less enantioselective (ee’s up to 80% in the reduction of trans -α-methylstilbene S4 ) …”

Section: Aryl- and Alkyl-substituted Alkenesmentioning

confidence: 99%

Asymmetric Hydrogenation of Olefins Using Chiral Crabtree-type Catalysts: Scope and Limitations

et al. 2013

View full text Add to dashboard Cite

Section: Aryl- and Alkyl-substituted Alkenesmentioning

confidence: 99%

Asymmetric Hydrogenation of Olefins Using Chiral Crabtree-type Catalysts: Scope and Limitations

et al. 2013

View full text Add to dashboard Cite

“…It is easy to hydrogenate substrates D with relatively high enantiomeric excesses using chiral analogs of Crabtree’s catalyst. For instance, Pfaltz’s group alone have published at least 18 research papers (excluding reviews) that feature hydrogenation of this particular substrate. ,− Figure shows some of the ligands that have been used to do this, the particular ester involved, and the enantiomeric excesses obtained. Figure shows ligands that Andersson’s group have used in similar hydrogenations. ,− Stereoselectivities in these reactions are relatively tolerant of simple changes to the ester–alkyl functionality, and high conversions are the norm (Figure ).…”

Section: Carboxylate Estersmentioning

confidence: 99%

Comparison of Asymmetric Hydrogenations of Unsaturated Carboxylic Acids and Esters

Khumsubdee

Burgess

2013

ACS Catal.

View full text Add to dashboard Cite

As methodology development matures it can be difficult to discern the most effective ways of performing certain transformations from the rest. This review summarizes the most important contributions leading to asymmetric hydrogenations of simple unsaturated-acid and ester substrates, with the objective of highlighting at least the best types of catalysts for each. Achievements in the area are described and these reveal situations where further efforts should be worthwhile, and ones where more research is only likely to give diminishing returns. In general, our conclusions are that the most useful types of catalysts for unsaturated-acids and -esters tend to be somewhat different, simple substrates have been studied extensively, and the field is poised to address more complex reactions. These could be ones involving alternative, particularly cyclic, structures, chemoselectivity issues, and more complex substrate stereochemistries.

show abstract

“…The Pfaltz group, in collaboration with the Moberg group, have also reported pyridine-phosphinite ligands derived from chiral pool materials. 157 These were used for asymmetric hydrogenation of a variety of trisubstituted styrenes, but in this instance e.e. values were highly substrate dependent, with good e.e.…”

Section: Reduction Reactions 21 Alkene Hydrogenationmentioning

confidence: 99%

Synthetic methods : Part (ii) Oxidation and reduction methods

Lewis

2009

Annu. Rep. Prog. Chem., Sect. B: Org. Chem.

View full text Add to dashboard Cite

highlights advances in some of the most commonly used oxidation and reduction reactions, focusing on the literature from 2008. Significant advances in oxidation chemistry include site-selective epoxidation of polyprenols, 6 bis(hydroxamic acid) ligands for vanadium(V)-catalysed highly enantioselective epoxidation of cis-disubstituted olefins, 40 a direct catalytic aziridination of styrenes with ammonia 112 and an aerobic rutheniumcatalysed alkene to aldehyde oxidation displaying non-Wacker regiochemistry. 133 Significant advances in reduction chemistry include adaptive supramolecular ''METAMORPhos'' ligands for asymmetric alkene hydrogenation, 160 early main-group metal catalysts for alkene hydrogenation 181 and the use of ''frustrated Lewis pairs'' to effect H 2 bond scission for imine and nitrile reduction. 191 1 Oxidation reactions 1.1 Alkene epoxidation 2008 has seen the publication of reviews on aspects of epoxidation chemistry from Shi 1 (ketone and iminium organocatalysts), Linic 2 (heterogeneous catalysis), Katsuki 3 (Ti(salan) complexes) and Walsh 4 (tandem one-pot synthesis of epoxy alcohols). Oyama has also edited a book on epoxidation mechanisms. 5 Corey and Gnanadesikan have reported a strategy for the site-selective epoxidation of polyprenols that utilises silyl ether-linked aryl peracids to effect intramolecular epoxidation. 6 The method uses specific aryl motifs that may be varied to effect epoxidation of differing polyprenol double bonds (Scheme 1).The reactions are run at high dilution (0.5 mM) to minimise intermolecular oxygen transfer with respect to the desired intramolecular process. Corey and Gnanadesikan report achieving 92% selectivity for the D 14 olefin in a pentaprenol, or 89% selectivity for the D 18 olefin in a hexaprenol when employing a biaryl peracid.2008 has seen several advances in organocatalytic asymmetric alkene epoxidation. Deng and co-workers have reported a catalytic asymmetric epoxidation of a,b-unsaturated ketones, employing a cinchona alkaloid-derived catalyst for in situ iminium formation. 7 Significantly, reaction conditions have been optimised such that a simple change in reaction temperature is sufficient to alter the course of the reaction from epoxidation to peroxidation; in both instances up to 97% e.e. was achievable. (Scheme 2). The List group independently and simultaneously developed an extremely similar catalytic system.

show abstract

Iridium-catalyzed asymmetric hydrogenation of olefins using pyridine-phosphinites derived from the chiral pool

Cited by 11 publications

References 12 publications

Asymmetric Hydrogenation of Olefins Using Chiral Crabtree-type Catalysts: Scope and Limitations

Asymmetric Hydrogenation of Olefins Using Chiral Crabtree-type Catalysts: Scope and Limitations

Comparison of Asymmetric Hydrogenations of Unsaturated Carboxylic Acids and Esters

Synthetic methods : Part (ii) Oxidation and reduction methods

Contact Info

Product

Resources

About