The mechanism investigation of chiral phosphoric acid-catalyzed Friedel–Crafts reactions – How the chiral phosphoric acid regains the proton

Liu, Chunhui; Han, Pan; Wu, Xiaoman; Tang, Mingsheng

doi:10.1016/j.comptc.2014.10.014

Cited by 15 publications

(3 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The second carbonyl of the ketomalonate is essential to fix the whole system in a rigid configuration. Besides, such a pathway basically coincides with the plausible mechanism provided by List and Liu et al for the addition of indolizines and N -methylpyrroles to enones and imines 38–40 .…”

Section: Resultssupporting

confidence: 88%

Phosphoric acid-catalyzed atroposelective construction of axially chiral arylpyrroles

et al. 2019

View full text Add to dashboard Cite

Axially chiral arylpyrroles are key components of pharmaceuticals and natural products as well as chiral catalysts and ligands for asymmetric transformations. However, the catalytic enantioselective construction of optically active arylpyrroles remains a formidable challenge. Here we disclose a highly efficient strategy to access enantioenriched axially chiral arylpyrroles by means of organocatalytic atroposelective desymmetrization and kinetic resolution. Depending on the remote control of chiral catalyst, the arylpyrroles were obtained in high yields and excellent enantioselectivities under mild reaction conditions. This strategy tolerates a wide range of functional groups, providing a facile avenue to approach axially chiral arylpyrroles from simple and readily available starting materials. Selected arylpyrrole products proved to be efficient chiral ligands in asymmetric catalysis and also important precursors for further synthetic transformations into highly functionalized pyrroles with potential bioactivity, especially the axially chiral fully substituted arylpyrroles.

show abstract

Section: Resultssupporting

confidence: 88%

Phosphoric acid-catalyzed atroposelective construction of axially chiral arylpyrroles

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Besides, such a pathway agrees with the mechanism theorised by other authors. 304,305 Concerning the enantioselective addition of indole derivatives to carbonyl compounds, the first example of such reaction was reported by Ma and co-workers in 2009 (Scheme 116a). 306 In particular, they discovered that the trifluoromethyl group has a double role for the enantioselective Friedel-Crafts addition to ketones.…”

Section: Friedel-crafts Reactionsmentioning

confidence: 99%

An overview of the applications of chiral phosphoric acid organocatalysts in enantioselective additions to CO and CN bonds

et al. 2022

View full text Add to dashboard Cite

show abstract

“…After TS, an irreversible proton-transfer follows, leading to the products 9 and the pyridine co-product. We have previously demonstrated [40], using an α-substituted nitroalkene giving a pro-chiral nitronate intermediate, that catalyst 5g is not able to exert significant stereocontrol in this proton-transfer process [48,49].…”

Section: Resultsmentioning

confidence: 99%

A General Catalytic Enantioselective Transfer Hydrogenation Reaction of β,β-Disubstituted Nitroalkenes Promoted by a Simple Organocatalyst

Bernardi

Fochi

2016

Molecules

View full text Add to dashboard Cite

Given its synthetic relevance, the catalytic enantioselective reduction of β,β-disubstituted nitroalkenes has received a great deal of attention. Several bio-, metal-, and organo-catalytic methods have been developed, which however are usually applicable to single classes of nitroalkene substrates. In this paper, we present an account of our previous work on this transformation, which implemented with new disclosures and mechanistic insights results in a very general protocol for nitroalkene reductions. The proposed methodology is characterized by (i) a remarkably broad scope encompassing various nitroalkene classes; (ii) Hantzsch esters as convenient (on a preparative scale) hydrogen surrogates; (iii) a simple and commercially available thiourea as catalyst; (iv) user-friendly procedures. Overall, the proposed protocol gives a practical dimension to the catalytic enantioselective reduction of β,β-disubstituted nitroalkenes, offering a useful and general platform for the preparation of nitroalkanes bearing a stereogenic center at the β-position in a highly enantioenriched form. A transition state model derived from control kinetic experiments combined with literature data is proposed and discussed. This model accounts and justifies the observed experimental results.

show abstract

The mechanism investigation of chiral phosphoric acid-catalyzed Friedel–Crafts reactions – How the chiral phosphoric acid regains the proton

Cited by 15 publications

References 37 publications

Phosphoric acid-catalyzed atroposelective construction of axially chiral arylpyrroles

Phosphoric acid-catalyzed atroposelective construction of axially chiral arylpyrroles

An overview of the applications of chiral phosphoric acid organocatalysts in enantioselective additions to CO and CN bonds

A General Catalytic Enantioselective Transfer Hydrogenation Reaction of β,β-Disubstituted Nitroalkenes Promoted by a Simple Organocatalyst

Contact Info

Product

Resources

About