scholarly journals Enantioselective synthesis of 3-substituted dihydrobenzofurans through iridium-catalyzed intramolecular hydroarylation

2021 ◽  
Author(s):  
Kana Sakamoto ◽  
Takahiro Nishimura
Keyword(s):  
Enantioselective Synthesis ◽  
Iridium Complex ◽  
High Yields ◽  
Chiral Bisphosphine Ligand

The enantioselective cyclization was efficiently catalyzed by a cationic iridium complex coordinated with a conventional chiral bisphosphine ligand to give benzofurans in high yields with high enantioselectivity.

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.

Enantioselective synthesis of tetrahydroisoquinolines via catalytic intramolecular asymmetric reductive amination

2021 ◽  
Author(s):  
Ruixia Liu ◽  
Jingkuo Han ◽  
Bin Li ◽  
Xian Liu ◽  
Zhao Wei ◽  
...  
Keyword(s):  
Reductive Amination ◽  
Enantioselective Synthesis ◽  
Iridium Complex ◽  
Highly Efficient ◽  
Efficient Access

A highly efficient intramolecular asymmetric reductive amination transformation catalyzed by an iridium complex of tBu-ax-Josiphos has been realized, providing an efficient access to various THIQ alkaloids.

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.

Intramolecular Addition of a Dimethylamino C(sp3)–H Bond across C–C Triple Bonds using IrCl(DTBM-SEGPHOS)(ethylene) Catalyst: Synthesis of Indoles from 2-Alkynyl-N-methylanilines

Synthesis ◽  
2021 ◽  
Author(s):  
Toshimichi Ohmura ◽  
Kaito Yagi ◽  
Takeru Torigoe ◽  
Michinori Suginome
Keyword(s):  
Double Bond ◽  
Triple Bond ◽  
Iridium Complex ◽  
Dimethylamino Group ◽  
Catalyst Synthesis ◽  
Double Bond Isomerization ◽  
Triple Bonds ◽  
High Yields

Intramolecular addition of a C(sp3)–H bond of a dimethylamino group across a C–C triple bond in 2-alkynyl-N,N-dimethylanilines was effectively catalyzed by a new iridium complex IrCl(DTBM-SEGPHOS)(C2H4) in mesitylene at 150 °C. The intramolecular C(sp3)–H addition was followed by double bond isomerization to afford 3-substituted indoles in good to high yields.

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