Lithiated three-membered heterocycles as chiral nucleophiles in the enantioselective synthesis of 1-oxaspiro[2,3]hexanes

2021 ◽  
Author(s):  
Andrea Cocco ◽  
Maria Grazia Rubanu ◽  
Maria Laura Sechi ◽  
Angelo Frongia ◽  
Pietro Mastrorilli ◽  
...  
Keyword(s):  
Styrene Oxide ◽  
Enantioselective Synthesis ◽  
High Yields

Enantiomerically enriched oxaspiro- and azaspirohexanes were synthesized through a two-step addition of configurably stable Li-styrene oxide (or aziridine) to 3-substituted cyclobutanones and base-mediated Payne rearrangement sequence with high yields and selectivity.

scholarly journals Enantioselective synthesis of seven-membered carbo- and heterocyles by organocatalyzed intramolecular Michael addition

RSC Advances ◽  
2016 ◽  
Vol 6 (36) ◽  
pp. 30166-30169 ◽  
Author(s):  
James O. Guevara-Pulido ◽  
José M. Andrés ◽  
Deisy P. Ávila ◽  
Rafael Pedrosa
Keyword(s):  
Michael Addition ◽  
Enantioselective Synthesis ◽  
High Yields

Enantioenriched seven membered rings have been prepared in high yields and stereoselectivities by intramolecular Michael addition of functionalized enals catalyzed by Jorgensen–Hayashi catalyst.

Catalytic Enantioselective Synthesis of Chiral Spirocyclic 1,3-Diketones via Organo-Cation Catalysis

2021 ◽  
Author(s):  
Xiao-Yan Zhang ◽  
Ya-Ping Shao ◽  
Bao-Kuan Guo ◽  
Kun Zhang ◽  
Fu-Min Zhang ◽  
...  
Keyword(s):  
Enantioselective Synthesis ◽  
High Yields ◽  
Convenient Access

An SPA-triazolium bromide catalyzed transannular C-acylation of enol lactones is presented. This methodology provides convenient access to a range of enantioenriched spirocyclic 1,3-diketones in moderate to high yields and enantioselectivities...

scholarly journals Organocatalytic Asymmetric Aldol Reaction of Arylglyoxals and Hydroxyacetone: Enantioselective Synthesis of 2,3-Dihydroxy-1,4-diones

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 648
Author(s):  
Yu-Hao Zhou ◽  
Yu-Zu Zhang ◽  
Zhu-Lian Wu ◽  
Tian Cai ◽  
Wei Wen ◽  
...  
Keyword(s):  
Primary Amine ◽  
Aldol Reaction ◽  
Enantioselective Synthesis ◽  
Asymmetric Aldol ◽  
Highly Efficient ◽  
Asymmetric Aldol Reaction ◽  
Aldol Addition ◽  
High Yields

A highly efficient quinine-derived primary-amine-catalyzed asymmetric aldol addition of hydroxyacetone to arylglyoxals is described. Structurally diverse anti-2,3-dihydroxy-1,4-diones were generated in high yields, with good diastereoselectivities and enantioselectivities.

Catalytic Asymmetric Substitution Reaction of 3-Substituted 2-Indolylmethanols with 2-Naphthols

Synthesis ◽  
2020 ◽  
Vol 52 (23) ◽  
pp. 3684-3692
Author(s):  
Feng Gao ◽  
Yu-Chen Zhang ◽  
Feng Shi ◽  
Jin-Ping Lan ◽  
Yi-Nan Lu ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Substitution Reaction ◽  
Enantioselective Synthesis ◽  
Chiral Phosphoric Acid ◽  
Catalytic Asymmetric ◽  
High Yields

A catalytic asymmetric substitution of 3-substituted 2-indolylmethanols with 2-naphthols has been established under the catalysis of chiral phosphoric acid. By this approach, a series of structurally diversified triarylmethane derivatives were obtained in moderate to high yields with good enantioselectivities (up to 97% yield, 95:5 er). This approach not only enriches the chemistry of 2-indolylmethanol-inolved catalytic asymmetric substitutions, but also provides a useful method for the enantioselective synthesis of chiral triarylmethane derivatives.

Enantioselective synthesis of fluorinated branched allylic compounds via Ir-catalyzed allylations of functionalized fluorinated methylene derivatives

2016 ◽  
Vol 14 (30) ◽  
pp. 7183-7186 ◽  
Author(s):  
Hongbo Zhang ◽  
Jiteng Chen ◽  
Xiao-Ming Zhao
Keyword(s):  
Enantioselective Synthesis ◽  
High Yields

Introduction of the functionalized monofluorinated methylenes into the allylic fragment under Ir catalysis gave the fluorinated branched allyl products in good to high yields with excellent regio- and enantioselectivities.

Novel enantioselective synthesis of (S)-ketamine using chiral auxiliary and precursor Mannich base

2019 ◽  
Vol 97 (5) ◽  
pp. 331-336 ◽  
Author(s):  
Seyed Jamaladdin Gohari ◽  
Abdollah Javidan ◽  
Abolghasem Moghimi ◽  
Mohammad Javad Taghizadeh ◽  
Maryam Iman
Keyword(s):  
Acid Solution ◽  
Nucleophilic Addition ◽  
Grignard Reagent ◽  
Mannich Base ◽  
Enantioselective Synthesis ◽  
Chiral Auxiliary ◽  
Chiral Auxiliaries ◽  
Anesthetic Drug ◽  
Directing Group ◽  
High Yields

Ketamine has been extensively used as an anesthetic drug. Chiral auxiliaries such as tert-butanesulfinamide (TBSA) can be used for the asymmetric synthesis of (S)-ketamine. Condensation of TBSA with ketones provides tert-butanesulfinylimines in consistently high yields. The tert-butanesulfinyl group actuates the imine for nucleophilic addition, is a potent chiral directing group, and after nucleophilic addition is easily dissociated by intervention with acid solution. To prepare 2-(N-piperidinomethyl)-1-phenylcyclohexylamine (1), we started with the cyclohexanone and using Mannich reaction achieved an aminoketone. Then, we made the sulfiniylamin (2) by the condensation of TBSA with aminoketone. By using salts such as Ti(OEt)4, we obtained N-tert-butanesulfinylketimine in 85% yield. Next, we provided a new chiral center (3) using Grignard reagent as nucleophile at −78 °C (80% yield). Finally, after many steps, the (S)-ketamine synthesized under ozonolysis conditions, with good yield and enantioselectivity (75% yield and 75% ee).

Highly enantioselective synthesis of naphthoquinones and pyranonaphthoquinones catalyzed by bifunctional chiral bis-squaramides

2015 ◽  
Vol 13 (18) ◽  
pp. 5243-5254 ◽  
Author(s):  
Nagaraju Molleti ◽  
Vinod K. Singh
Keyword(s):  
Conjugate Addition ◽  
Enantioselective Synthesis ◽  
High Yields

A variety of enantioenriched naphthoquinones has been synthesized in high yields and excellent enantioselectivities (up to >99% ee) using a bifunctional chiral bis-squaramide catalyzed conjugate addition of 2-hydroxy-1,4-naphthoquinone to 2-enoylpyridines.

Asymmetric Brønsted Acid-catalyzed Intramolecular aza-Michael Reaction – Enantioselective Synthesis of Dihydroquinolinones

2012 ◽  
Vol 67 (10) ◽  
pp. 1021-1029 ◽  
Author(s):  
Magnus Rueping ◽  
Stefan A. Moreth ◽  
Michael Bolte
Keyword(s):  
Michael Addition ◽  
Heterocyclic Compounds ◽  
Michael Reaction ◽  
Biological Activities ◽  
Enantioselective Synthesis ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Brönsted Acid ◽  
Acid Catalyzed ◽  
High Yields

The enantioselective synthesis of 2-aryl-substituted 2,3-dihydroquinolin-4-ones, a class of heterocyclic compounds with interesting biological activities, has been achieved through a Brønsted acidcatalyzed enantioselective intramolecular Michael addition. The products are available in moderate to high yields and with good enantioselectivities.

Enantioselective synthesis of chiral α,β-unsaturated γ-substituted butyrolactams by organocatalyzed direct asymmetric vinylogous Michael addition of α,β-unsaturated γ-butyrolactam to 2-enoylpyridines

2016 ◽  
Vol 14 (27) ◽  
pp. 6568-6576 ◽  
Author(s):  
Zhen-Hua Wang ◽  
Zhi-Jun Wu ◽  
Deng-Feng Yue ◽  
Yong You ◽  
Xiao-Ying Xu ◽  
...  
Keyword(s):  
Michael Addition ◽  
Optically Active ◽  
Enantioselective Synthesis ◽  
High Yields

Approach providing a series of optically active α,β-unsaturated γ-substituted butyrolactams in high yields with excellent diastereo- and enantioselectivities.

Enantioselective synthesis of dihydroquinazolinone derivatives catalyzed by a chiral organocatalyst

2017 ◽  
Vol 41 (16) ◽  
pp. 7980-7986 ◽  
Author(s):  
Siva Ayyanar ◽  
Ponmuthu Kottala Vijaya ◽  
Madhappan Mariyappan ◽  
Veeramanoharan Ashokkumar ◽  
Velu Sadhasivam ◽  
...  
Keyword(s):  
Cascade Reaction ◽  
Enantioselective Synthesis ◽  
Amine Addition ◽  
High Yields

The asymmetric condensation/amine addition cascade reaction catalysed by a effective chiral organocatalyst for the formation of 2,3-dihydroquinazolinones with high yields (up to 99%) and ee's (up to 97%).

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