scholarly journals Multicomponent and multicatalytic asymmetric synthesis of furo[2,3-b]pyrrole derivatives: further insights into the mode of action of chiral phosphoric acid catalysts

2020 ◽  
Vol 11 (34) ◽  
pp. 9181-9190
Author(s):  
Lara Cala ◽  
Pedro Villar ◽  
Ángel R. de Lera ◽  
Francisco J. Fañanás ◽  
Rosana Álvarez ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Asymmetric Synthesis ◽  
Multicomponent Reaction ◽  
Mode Of Action ◽  
Acid Catalysts ◽  
Acid System ◽  
Pyrrole Derivatives ◽  
Chiral Phosphoric Acid ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Furo[2,3-b]pyrroles are selectively synthesized by a multicomponent reaction catalysed by a gold/chiral phosphoric acid system. The non-covalent interactions established between the acid and the reagents explain the exquisite stereoselectivity.

Organocatalytic asymmetric synthesis of benzazepinoindole derivatives with trifluoromethylated quaternary stereocenters by chiral phosphoric acid catalysts

2018 ◽  
Vol 16 (8) ◽  
pp. 1367-1374 ◽  
Author(s):  
Abdul Rahman ◽  
En Xie ◽  
Xufeng Lin
Keyword(s):  
Phosphoric Acid ◽  
Asymmetric Synthesis ◽  
Acid Catalysts ◽  
Chiral Phosphoric Acid ◽  
Quaternary Stereocenters

An enantioselective aza-Friedel–Crafts reaction of trifluoromethyl dihydrobenzoazepinoindoles with pyrroles or indoles catalyzed by a chiral spirocyclic phosphoric acid was developed.

scholarly journals Enantioselective Hydroamination of Alkenes with Sulfonamides Enabled by Proton-Coupled Electron Transfer

2020 ◽  
Author(s):  
Casey B. Roos ◽  
Joachim Demaerel ◽  
David E. Graff ◽  
Robert Knowles
Keyword(s):  
Electron Transfer ◽  
Phosphoric Acid ◽  
Open Shell ◽  
Asymmetric Induction ◽  
Bond Forming ◽  
Proton Coupled Electron Transfer ◽  
Chiral Phosphoric Acid ◽  
Non Covalent Interactions ◽  
Covalent Interactions

<div><p>An enantioselective, radical-based method for the intramolecular hydroamination of alkenes with sulfonamides is reported. These reactions are proposed to proceed <i>via</i> <i>N</i>-centered radicals formed by proton-coupled electron transfer (PCET) activation of sulfonamide N–H bonds. Non-covalent interactions between the neutral sulfonamidyl radical and a chiral phosphoric acid generated in the PCET event are hypothesized to serve as the basis for asymmetric induction in a subsequent C–N bond forming step, achieving selectivities of up to 98:2 er. These results offer further support for the ability of non-covalent interactions to enforce stereoselectivity in reactions of transient and highly reactive open-shell intermediates.</p></div>

scholarly journals Enantioselective Hydroamination of Alkenes with Sulfonamides Enabled by Proton-Coupled Electron Transfer

2020 ◽  
Author(s):  
Casey B. Roos ◽  
Joachim Demaerel ◽  
David E. Graff ◽  
Robert Knowles
Keyword(s):  
Electron Transfer ◽  
Phosphoric Acid ◽  
Open Shell ◽  
Asymmetric Induction ◽  
Bond Forming ◽  
Proton Coupled Electron Transfer ◽  
Chiral Phosphoric Acid ◽  
Non Covalent Interactions ◽  
Covalent Interactions

<div><p>An enantioselective, radical-based method for the intramolecular hydroamination of alkenes with sulfonamides is reported. These reactions are proposed to proceed <i>via</i> <i>N</i>-centered radicals formed by proton-coupled electron transfer (PCET) activation of sulfonamide N–H bonds. Non-covalent interactions between the neutral sulfonamidyl radical and a chiral phosphoric acid generated in the PCET event are hypothesized to serve as the basis for asymmetric induction in a subsequent C–N bond forming step, achieving selectivities of up to 98:2 er. These results offer further support for the ability of non-covalent interactions to enforce stereoselectivity in reactions of transient and highly reactive open-shell intermediates.</p></div>

scholarly journals QM/MM study on the enantioselectivity of spiroacetalization catalysed by an imidodiphosphoric acid catalyst: how confinement works

2016 ◽  
Vol 14 (11) ◽  
pp. 3031-3039 ◽  
Author(s):  
Luis Simón ◽  
Robert S. Paton
Keyword(s):  
Phosphoric Acid ◽  
Acid Catalyst ◽  
Acid Catalysts ◽  
Chiral Phosphoric Acid

An explanation of why confined imidodiphosphoric acid catalyst succeeds where other chiral phosphoric acid catalysts fail.

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.

Asymmetric Synthesis of t-Butyl 3-Alkyl-oxindole-3-carboxylates via Chiral Phosphoric Acid Catalyzed Desymmetrization of Di-t-butyl 2-Alkyl-2-(2-aminophenyl)malonates

Heterocycles ◽  
2019 ◽  
Vol 99 (2) ◽  
pp. 1398
Author(s):  
Takaaki Sumiyoshi ◽  
Kyoji Ishida ◽  
Masahiro Shimizu ◽  
Yu-suke Yamai ◽  
Itaru Natsutani ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Asymmetric Synthesis ◽  
Chiral Phosphoric Acid ◽  
Acid Catalyzed

Direct enantioselective Mannich reactions of α-azido cyclic ketones: asymmetric construction of chiral azides possessing an α-quaternary stereocenter

2020 ◽  
Vol 56 (1) ◽  
pp. 98-101 ◽  
Author(s):  
Xueqian Ye ◽  
Yongkai Pan ◽  
Xiaoyu Yang
Keyword(s):  
Phosphoric Acid ◽  
Asymmetric Synthesis ◽  
Cyclic Ketones ◽  
Mannich Reactions ◽  
Chiral Phosphoric Acid ◽  
Quaternary Stereocenter

Herein, we report the asymmetric synthesis of chiral azides possessing an α-quaternary stereocenter via chiral phosphoric acid catalysed direct enantioselective Mannich reactions of α-azido cyclic ketones with aldimines.

Sign in / Sign up

Export Citation Format

Share Document