scholarly journals Organocatalytic enantioselective dearomatization of thiophenes by 1,10-conjugate addition of indole imine methides

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xingguang Li ◽  
Meng Duan ◽  
Peiyuan Yu ◽  
K. N. Houk ◽  
Jianwei Sun
Keyword(s):  
Hydrogen Bonding ◽  
Phosphoric Acid ◽  
Nucleophilic Addition ◽  
Acid Catalysis ◽  
Conjugate Addition ◽  
Mild Conditions ◽  
Rapid Construction ◽  
Chiral Phosphoric Acid ◽  
Cyclic Molecules ◽  
Selectivity Control

AbstractCatalytic asymmetric dearomatization (CADA) is a powerful tool for the rapid construction of diverse chiral cyclic molecules from cheap and easily available arenes. This work reports an organocatalytic enantioselective dearomatization of substituted thiophenes in the context of a rare remote asymmetric 1,10-conjugate addition. By suitable stabilization of the thiophenyl carbocation with an indole motif in the form of indole imine methide, excellent remote chemo-, regio-, and stereocontrol in the nucleophilic addition can be achieved with chiral phosphoric acid catalysis under mild conditions. This protocol can be successfully extended to the asymmetric dearomatization of other heteroarenes including selenophenes and furans. Control experiments and DFT calculations demonstrate a possible pathway in which hydrogen bonding plays an important role in selectivity control.

The first catalytic asymmetric thioacetalization by chiral phosphoric acid catalysis

2016 ◽  
Vol 14 (7) ◽  
pp. 2205-2209 ◽  
Author(s):  
Jin-Sheng Yu ◽  
Wen-Biao Wu ◽  
Feng Zhou
Keyword(s):  
Phosphoric Acid ◽  
Acid Catalysis ◽  
Mild Conditions ◽  
Chiral Phosphoric Acid ◽  
Catalytic Asymmetric

We report here the first catalytic asymmetric thioacetalization of salicylaldehyde and dithiol. Chiral phosphoric acid STRIP C5 is identified as a powerful catalyst for this reaction to afford various chiral dithioacetals in high to excellent yields and enantioselectivities under mild conditions.

scholarly journals Catalytic Enantioselective Synthesis of 4-Amino-1,2,3,4-tetrahydropyridine Derivatives from Intramolecular Nucleophilic Addition Reaction of Tertiary Enamides

Synlett ◽  
2018 ◽  
Vol 30 (04) ◽  
pp. 483-487 ◽  
Author(s):  
Shuo Tong ◽  
Mei-Xiang Wang
Keyword(s):  
Phosphoric Acid ◽  
Asymmetric Catalysis ◽  
Nucleophilic Addition ◽  
Addition Reaction ◽  
Enantioselective Synthesis ◽  
Chiral Phosphoric Acid ◽  
Substrate Engineering ◽  
Nucleophilic Addition Reaction ◽  
Engineering Strategy ◽  
Acid Catalyzed

A general and efficient method for the synthesis of highly enantiopure 4-amino-1,2,3,4-tetradydropyridine derivatives based on chiral phosphoric acid catalyzed intramolecular nucleophilic addition of tertiary enamides to imines has been developed. We have also demonstrated a substrate engineering strategy to significantly improve the enantioselectivity of asymmetric catalysis

Asymmetric C-H and N-H functionalization of Indoles involving Central Chirality via Chiral Phosphoric Acid Catalysis

2021 ◽  
Vol 18 ◽  
Author(s):  
Alemayehu Gashaw ◽  
Dereje Kebebew Debeli ◽  
Meseret Chemeda
Keyword(s):  
Phosphoric Acid ◽  
Organic Compounds ◽  
Organic Synthesis ◽  
Acid Catalysis ◽  
Bond Formation ◽  
Acid Catalysts ◽  
Asymmetric Syntheses ◽  
Chiral Phosphoric Acid ◽  
Great Progress ◽  
Interesting Area

: The C-H and N-H functionalization of indoles is an interesting area of research that has a useful impact on organic synthesis due to the availability of chiral indole scaffolds in the discovery of drugs, synthetic bioactive compounds, and natural products. The chiral phosphoric acid catalysts (CPAs) have proven to be a powerful and versatile class of enantioselective organocatalysts. Many asymmetric syntheses of organic compounds have been carried out with these catalysts in C–C and C-N bond formation reactions, and great progress has been reported. By 2011, several reviews were published covering some important topics and recent achievements in this field. Therefore, in this review, the most recent advances, research breakthroughs with key examples involving mechanisms of CPA-catalyzed C-H and N-H functionalization of indoles to form central chirality via Friedel Crafts, Michael type, and rearrangement reactions were reviewed and reported.

Enantioselective transfer hydrogenation, a key step for the synthesis of 3-aminotetrahydroquinolines

2016 ◽  
Vol 40 (11) ◽  
pp. 9034-9037 ◽  
Author(s):  
Alexandre Aillerie ◽  
Vincent Lemau de Talencé ◽  
Clément Dumont ◽  
Sylvain Pellegrini ◽  
Frédéric Capet ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Catalytic Amount ◽  
Transfer Hydrogenation ◽  
Mild Conditions ◽  
Chiral Phosphoric Acid

An enantioselective transfer hydrogenation has been successfully achieved to furnish 3-aminotetrahydroquinolines. The reaction was conducted in the presence of Hantzsch dihydropyridine and a catalytic amount of chiral phosphoric acid under mild conditions.

Asymmetric synthesis of CF3- and indole-containing tetrahydro-β-carbolines via chiral spirocyclic phosphoric acid-catalyzed aza-Friedel–Crafts reaction

2017 ◽  
Vol 4 (7) ◽  
pp. 1407-1410 ◽  
Author(s):  
En Xie ◽  
Abdul Rahman ◽  
Xufeng Lin
Keyword(s):  
Phosphoric Acid ◽  
Asymmetric Synthesis ◽  
Acid Catalysis ◽  
Chiral Phosphoric Acid ◽  
Acid Catalyzed ◽  
Quaternary Stereocenter

An enantioselective aza-Friedel–Crafts reaction of indoles with 1-trifluoromethyl-3,4-dihydro-β-carbolines has been developed to afford tetrahydro-β-carbolines with a CF3- and indole-containing quaternary stereocenter by using chiral phosphoric acid catalysis.

Organocatalytic Stereoselective 1,6-Addition of Thiolacetic Acids to Propargylic Indole Imine Methides: Access to Axially Chiral Sulfur-containing Tetrasubstituted Allenes

2021 ◽  
Author(s):  
Ziyang Wang ◽  
Xiao Lin ◽  
Xuling Chen ◽  
Pengfei Li ◽  
Wenjun Li
Keyword(s):  
Phosphoric Acid ◽  
Conjugate Addition ◽  
Chiral Phosphoric Acid ◽  
Axially Chiral ◽  
Propargylic Alcohol ◽  
Acid Catalyzed ◽  
Sulfur Containing ◽  
Thiolacetic Acid

A chiral phosphoric acid catalyzed enantioselective 1,6-conjugate addition of thiolacetic acid to propargylic indole imine methide in situ formed from α-(3-indolyl) propargylic alcohol has been established, which enables the formation...

scholarly journals Chiral phosphoric acid-catalyzed stereodivergent synthesis of trisubstituted allenes and computational mechanistic studies

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiawen Wang ◽  
Sujuan Zheng ◽  
Subramani Rajkumar ◽  
Jinglei Xie ◽  
Na Yu ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Density Functional ◽  
Acid Catalysis ◽  
Chiral Molecules ◽  
Functional Theory ◽  
Chiral Phosphoric Acid ◽  
Acid Catalyzed ◽  
Asymmetric Additions ◽  
Formation Step ◽  
Stagger Form

Abstract Chiral molecules with multiple stereocenters are widely present in natural products and pharmaceuticals, whose absolute and relative configurations are both critically important for their physiological activities. In spite of the fact that a series of ingenious strategies have been developed for asymmetric diastereodivergent catalysis, most of these methods are limited to the divergent construction of point chirality. Here we report an enantioselective and diastereodivergent synthesis of trisubstituted allenes by asymmetric additions of oxazolones to activated 1,3-enynes enabled by chiral phosphoric acid (CPA) catalysis, where the divergence of the allenic axial stereogenicity is realized by modifications of CPA catalysts. Density functional theory (DFT) calculations are performed to elucidate the origin of diastereodivergence by the stacking- and stagger-form in the transition state (TS) of allene formation step, as well as to disclose a Münchnone-type activation mode of oxazolones under Brønsted acid catalysis.

Sign in / Sign up

Export Citation Format

Share Document