Enantioselective synthesis of pyrano[2,3-c]pyrrole via an organocatalytic [4 + 2] cyclization reaction of dioxopyrrolidines and azlactones

2019 ◽  
Vol 17 (16) ◽  
pp. 3945-3950 ◽  
Author(s):  
Yichen Wang ◽  
Yuzhen Chen ◽  
Xiaoping Li ◽  
Yukang Mao ◽  
Weiwen Chen ◽  
...  
Keyword(s):  
Enantioselective Synthesis ◽  
Cyclization Reaction ◽  
Efficient Access

The present work provides a simple and efficient access to chiral pyrano[2,3-c]pyrrole via an asymmetric [4 + 2] cyclization reaction catalyzed by a cinchona-squaramide catalyst.

Enantioselective synthesis of chiral 3-alkyl-3-nitro-4-chromanones via chiral thiourea-catalysed intramolecular Michael-type cyclization

2021 ◽  
Author(s):  
Huiqing Chen ◽  
Jie Tang ◽  
Ting Liu ◽  
Li-Fang Yu ◽  
Dong Xing ◽  
...  
Keyword(s):  
Enantioselective Synthesis ◽  
Cyclization Reaction ◽  
Rapid Construction

Herein we report an enantioselective method for the rapid construction of chiral 3-nitro-4-chromanones via a chiral thiourea-catalyzed intramolecular Michael-type cyclization reaction. With this method, a series of 3,3-disubstituted-3-nitro-4-chromanones bearing contiguous...

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 Organocatalytic Discrimination of Non-Directing Aryl and Heteroaryl Groups: Enantioselective Synthesis of Bioactive Indole-Containing Triarylmethanes

2021 ◽  
Author(s):  
Qiaolin Yan ◽  
Meng Duan ◽  
Cien Chen ◽  
Zhiqin Deng ◽  
Mandi Wu ◽  
...  
Keyword(s):  
Asymmetric Catalysis ◽  
Spatial Interaction ◽  
Antiviral Drug ◽  
Kinetic Studies ◽  
Enantioselective Synthesis ◽  
Asymmetric Induction ◽  
Efficient Access ◽  
Chiral Phosphoric Acid ◽  
Biological Studies ◽  
Directing Group

Despite the enormous developments of asymmetric catalysis, the basis for asymmetric induction is largely limited to spatial interaction between substrate and catalyst. Consequently, asymmetric discrimination between two sterically similar groups remains a challenge. This is particularly formidable for enantiodifferentiation between aryl and heteroaryl groups without a directing group or electronic manipulation. Here we address this challenge by a robust organocatalytic system leading to excellent enantioselection between aryl and heteroaryl groups. With the versatile 2-indole imine methide as platform, an excellent combination of a superb chiral phosphoric acid and the optimal hydride source provided efficient access to a range of highly enantioenriched indole-containing triarylmethanes. Control experiments and kinetic studies provided important insights into the mechanism. DFT calculations also indicated that, while hydrogen bonding is important for activation, the key interaction for discrimination of the two aryl groups is mainly π-π stacking. Preliminary biological studies also demonstrated the great potential of these triarylmethanes for anticancer and antiviral drug development.

scholarly journals Transition-Metal-Free [3+2] Dehydration Cycloaddition of Donor-Acceptor Cyclopropanes With 2-Naphthols

2021 ◽  
Vol 9 ◽  
Author(s):  
Hua Zhao ◽  
Peng Shen ◽  
Dongru Sun ◽  
Hongbin Zhai ◽  
Yufen Zhao
Keyword(s):  
Transition Metal ◽  
Ring Opening ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Cyclization Reaction ◽  
Metal Free ◽  
Efficient Access ◽  
Donor Acceptor ◽  
Acid Catalyzed ◽  
Synthetic Application

A Brønsted acid-catalyzed domino ring-opening cyclization transformation of donor-acceptor (D-A) cyclopropanes and 2-naphthols has been developed. This formal [3+2] cyclization reaction provided novel and efficient access to the naphthalene-fused cyclopentanes in the absence of any transition-metal catalysts or additives. This robust procedure was completed smoothly on a gram-scale to afford the corresponding product with comparable efficiency. Furthermore, the synthetic application of the prepared product has been demonstrated by its transformation into a variety of synthetically useful molecules.

Chiral Phosphoric Acid-Catalyzed Enantioselective [4+3] Cyclization Reaction of 4-Indolylmethanols and Quinone Esters

Synlett ◽  
2021 ◽  
Author(s):  
Zhouli Chen ◽  
Lei Wang ◽  
Yiheng Qian ◽  
Xufeng Lin
Keyword(s):  
Phosphoric Acid ◽  
Cyclization Reaction ◽  
Reaction Conditions ◽  
Efficient Access ◽  
Single Diastereomer ◽  
Chiral Phosphoric Acid ◽  
Acid Catalyzed ◽  
Phosphoric Acids

An asymmetric [4+3] cyclization reaction of racemic 4-indolylmethanols and quinone esters catalyzed by chiral phosphoric acids has been developed. This method provides efficient access to biologically important benzoxepino[5,4,3-cd] indoles featuring both axial and central chirality in good yields with up to 98% ee and essentially single diastereomer in mild reaction conditions.

Enantioselective total synthesis of (+)-arborescidine C and related tetracyclic indole alkaloids using organocatalysis

2017 ◽  
Vol 15 (16) ◽  
pp. 3408-3412 ◽  
Author(s):  
Vishal M. Sheth ◽  
Bor-Cherng Hong ◽  
Gene-Hsiang Lee
Keyword(s):  
Total Synthesis ◽  
Indole Alkaloids ◽  
Enantioselective Synthesis ◽  
Cyclization Reaction ◽  
Enantioselective Total Synthesis

Enantioselective synthesis of (+)-arborescidine C was achieved by the key step of Pictet–Spengler cyclization reaction with a Jacobsen-type thiourea organocatalyst.

scholarly journals Enantioselective total synthesis of (R)-(−)-complanine

2012 ◽  
Vol 8 ◽  
pp. 1695-1699 ◽  
Author(s):  
Krystal A D Kamanos ◽  
Jonathan M Withey
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Causative Agent ◽  
Enantioselective Synthesis ◽  
Marine Natural Product ◽  
Enantioselective Total Synthesis ◽  
Efficient Access

A route is described for the enantioselective synthesis of (R)-(−)-complanine, a marine natural product isolated from Eurythoe complanata, and known to be a causative agent in inflammation. An organocatalytic, asymmetric oxyamination of a homoconjugated all-Z-dienal intermediate provides versatile and efficient access to the natural product.

Rhodium-mediated asymmetric transfer hydrogenation: a diastereo- and enantioselective synthesis of syn-α-amido β-hydroxy esters

2018 ◽  
Vol 54 (3) ◽  
pp. 283-286 ◽  
Author(s):  
Long-Sheng Zheng ◽  
Charlène Férard ◽  
Phannarath Phansavath ◽  
Virginie Ratovelomanana-Vidal
Keyword(s):  
Enantioselective Synthesis ◽  
Transfer Hydrogenation ◽  
Asymmetric Transfer Hydrogenation ◽  
Keto Esters ◽  
Ru Complex ◽  
Efficient Access ◽  
Hydroxy Esters

The use of a Rh- instead of a Ru-complex in the asymmetric transfer hydrogenation of α-benzoylamino β-keto esters allowed a reversal of diastereoselectivity and an efficient access to a variety of syn α-amido β-hydroxy esters.

scholarly journals Organocatalytic Discrimination of Non-Directing Aryl and Heteroaryl Groups: Enantioselective Synthesis of Bioactive Indole-Containing Triarylmethanes

2021 ◽  
Author(s):  
Jianwei Sun ◽  
Qiaolin Yan ◽  
Meng Duan ◽  
Cien Chen ◽  
Zhiqin Deng ◽  
...  
Keyword(s):  
Asymmetric Catalysis ◽  
Spatial Interaction ◽  
Antiviral Drug ◽  
Kinetic Studies ◽  
Enantioselective Synthesis ◽  
Asymmetric Induction ◽  
Efficient Access ◽  
Chiral Phosphoric Acid ◽  
Biological Studies ◽  
Directing Group

Despite the enormous developments of asymmetric catalysis, the basis for asymmetric induction is largely limited to spatial interaction between substrate and catalyst. Consequently, asymmetric discrimination between two sterically similar groups remains a challenge. This is particularly formidable for enantiodifferentiation between aryl and heteroaryl groups without a directing group or electronic manipulation. Here we address this challenge by a robust organocatalytic system leading to excellent enantioselection between aryl and heteroaryl groups. With the versatile 2-indole imine methide as platform, an excellent combination of a superb chiral phosphoric acid and the optimal hydride source provided efficient access to a range of highly enantioenriched indole-containing triarylmethanes. Control experiments and kinetic studies provided important insights into the mechanism. DFT calculations also indicated that, while hydrogen bonding is important for activation, the key interaction for discrimination of the two aryl groups is mainly π-π stacking. Preliminary biological studies also demonstrated the great potential of these triarylmethanes for anticancer and antiviral drug development.

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