Dual Organocatalytic Activation of Isatins and Formaldehyde <i>tert</i>‐Butyl Hydrazone: Asymmetric Synthesis of Functionalized 3‐Hydroxy‐2‐oxindoles

Monge, David; Crespo-Peña, Ana M.; Martı́n-Zamora, Eloı́sa; Álvarez, Eleuterio; Fernández, Rosario; Lassaletta, José M.

doi:10.1002/chem.201301351

Cited by 35 publications

(10 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, none of these catalysts provided satisfactory results for the 1,2‐addition of DAHs to carbonyl compounds. Alternatively, we have exploited the distinct properties of FTBH in reactions with activated carbonyl compounds (α‐keto esters, α‐keto phosphonates, and isatins) to afford highly functionalized β‐hydroxydiazenes (Scheme B). Dual activation by axially chiral 1,1′‐binaphthyl‐2,2′‐diamine (BINAM) bis‐ureas (BINAM) bis‐ureas, which behaved as bifunctional organocatalysts, proved to be key to achieving good catalytic activities and stereocontrol.…”

Section: Introductionmentioning

confidence: 99%

Bifunctional Squaramide Organocatalysts for the Asymmetric Addition of Formaldehyde tert‐Butylhydrazone to Simple Aldehydes

Matador

Retamosa

Monge

et al. 2018

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

The nucleophilic addition of formaldehyde tert-butylhydrazone to simple aldehydes (a formal hetero-carbonyl-ene reaction) can be performed with good reactivity and excellent enantioselectivity by virtue of the dual hydrogen-bonding activation exerted by amide-squaramide organocatalysts. The resulting hydroxydiazenes (azo alcohols) were isolated in high yields as enantiomerically enriched azoxy compounds after a regioselective azo-to-azoxy transformation. Subsequent derivatization provides an entry to relevant amino alcohols, oxazolidinones, and derivatives thereof.

show abstract

Section: Introductionmentioning

confidence: 99%

Bifunctional Squaramide Organocatalysts for the Asymmetric Addition of Formaldehyde tert‐Butylhydrazone to Simple Aldehydes

Matador

Retamosa

Monge

et al. 2018

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

show abstract

“…Subsequently, the authors further expanded the substrate scope of this strategy by utilizing chiral bis‐urea 114a or 114c . Both isatins and acyl phosphonates were employed and furnished the corresponding 3‐hydroxy‐2‐oxindoles 116 and α‐hydroxy phosphonates 118 in excellent yields and enantioselectivities (Scheme ). However, in view of the sensitivity and instability of these compounds, they were hence further oxidized to the respective azoxy compounds 117 and 119 by magnesium monoperoxyphthalate (NMPP) without erosion of the enantioselectivity.…”

Section: Ketone‐(hetero)ene Reactionsmentioning

confidence: 99%

Recent Advances in Catalytic Asymmetric Synthesis of Tertiary Alcohols via Nucleophilic Addition to Ketones

2018

View full text Add to dashboard Cite

Chiral tertiary alcohols are an important class of organic compounds which have found wide applications in both academia and industry. Therefore, various synthetic strategies towards these compounds have already been developed. Among them, the catalytic asymmetric addition of carbon nucleophiles to ketones is the most desirable route owing to its straightforwardness as well as its economic, efficient and versatile advantages. This review summarizes and discusses the recent achievements in this field classified according to the reaction types. Special attention is paid to the mechanisms, advantages and limitations of each reaction. In addition, the applications of these catalytic processes in the synthesis of related natural products, pharmaceuticals or their analogues are briefly discussed as well.

show abstract

“…However, even in the presence of high catalyst loading (100 mol%) and in the presence of DABCO (1,4diazabicyclo[2.2.2]octane), the enantioselectivity values were moderate (up to 78% ee) [89]. Better stereocontrol was achieved with catalyst C23 (Scheme 17 b)) in the reaction of isatin derivatives and formaldehyde N-tert-butyl hydrazine, with the resulting chiral 3-hydroxy-3-substituted-oxindole derivatives presenting enantioselectivities of up to 99% ee with good to excellent yields [90].…”

Section: Urea and Thiourea Derivativesmentioning

confidence: 99%

Recent advances in the asymmetric catalytic synthesis of chiral 3-hydroxy and 3-aminooxindoles and derivatives: Medicinally relevant compounds

Brandão

Burke

2018

Tetrahedron

View full text Add to dashboard Cite

Several oxindole derivatives, of natural or synthetic origin, have been identified as medicinally appealing compounds, with a plethora of bioactivities reported. Chiral 3-hydroxy and 3-aminooxindole scaffolds have captured the attention of several research groups, due to their importance in drug discovery. In this review, we systematically address the wide variety of asymmetric catalytic methodologies employed in the preparation of these relevant chiral scaffolds, present in many biologically active compounds and/or natural products. Special focus will be given to the nature of the catalyst used.

show abstract

Dual Organocatalytic Activation of Isatins and Formaldehyde tert‐Butyl Hydrazone: Asymmetric Synthesis of Functionalized 3‐Hydroxy‐2‐oxindoles

Cited by 35 publications

References 34 publications

Bifunctional Squaramide Organocatalysts for the Asymmetric Addition of Formaldehyde tert‐Butylhydrazone to Simple Aldehydes

Bifunctional Squaramide Organocatalysts for the Asymmetric Addition of Formaldehyde tert‐Butylhydrazone to Simple Aldehydes

Recent Advances in Catalytic Asymmetric Synthesis of Tertiary Alcohols via Nucleophilic Addition to Ketones

Recent advances in the asymmetric catalytic synthesis of chiral 3-hydroxy and 3-aminooxindoles and derivatives: Medicinally relevant compounds

Contact Info

Product

Resources

About