Enantioselective Dearomative [4+2] Cycloaddition Reaction of 1‐Naphthols with In‐Situ Generated ortho‐Quinone Methides DOI

Sushree Ranjan Sahoo,

Khushboo Gupta,

Vinod K. Singh

et al.

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(69)

Published: Sept. 14, 2023

We disclose a catalytic, enantioselective dearomative reaction of non-functionalized 1-naphthols, which poses synthetic challenge to organic chemists because the relative ease rearomatization via elimination proton. In this work, direct dearomatization 1-naphthols was achieved through chiral phosphoric acid (CPA) catalyzed [4+2] cycloaddition with in-situ generated ortho-quinone methides (o-QMs). The reported convergent method allows use readily available simple without pre-functionalization, furnishing variety naphthopyran derivatives in good yields (up 96 %) and moderate excellent enantioselectivities >99 % ee) under mild conditions. observed regio-, diastereo-, are keys success current strategy utilizing o-QM as diene surrogates, combination CPA catalysis.

Language: Английский

Synthesis of homophthalimide spironaphthalenones through [5 + 1] spiroannulation of aryl/alkenyl enaminones with diazo homophthalimides DOI

Chun Xia Yang,

Xinying Zhang, Xuesen Fan

et al.

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(17), P. 4282 - 4288

Published: Jan. 1, 2023

Presented herein is a novel synthesis of homophthalimide spironaphthalenones from the cascade reaction enaminones with diazo homophthalimides.

Language: Английский

Citations

20
Catalyst-Substrate Helical Character Matching Determines the Enantioselectivity in the Ishihara-Type Iodoarenes Catalyzed Asymmetric Kita-Dearomative Spirolactonization DOI
Hanliang Zheng, Cai Liu,

Ming Pan

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(13), P. 7301 - 7312

Published: March 20, 2023

Catalyst design has traditionally focused on rigid structural elements to prevent conformational flexibility. Ishihara's elegant of conformationally flexible C2-symmetric iodoarenes, a new class privileged organocatalysts, for the catalytic asymmetric dearomatization (CADA) naphthols is notable exception. Despite widespread use Ishihara catalysts CADAs, reaction mechanism remains subject debate, and mode induction not been well established. Here, we report an in-depth computational investigation three possible mechanisms in literature. Our results, however, reveal that this best rationalized by fourth called "proton-transfer-coupled-dearomatization (PTCD)", which predicted be strongly favored over other competing pathways. The PTCD consistent with control experiment further validated applying it rationalize enantioselectivities. Oxidation I(I) catalyst active I(III) species induces defined helical chiral environment delicate balance between flexibility rigidity. A match/mismatch effect substrate's shape transition states was observed. match allows adapt its conformation maximize attractive noncovalent interactions, including I(III)···O halogen bond, N-H···O hydrogen π···π stacking, stabilize state. stereochemical model capable rationalizing variation enantioselectivities developed. present study enriches our understanding how achieve high stereoinduction may serve as inspiration future exploration designs.

Language: Английский

Citations

17
Asymmetric Aminative Dearomatization of 2-Naphthols via Non-covalent N-Heterocyclic Carbene Catalysis DOI

Ujjwal Maji,

Bhaskar Mondal, Joyram Guin

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(13), P. 2323 - 2327

Published: March 30, 2023

Herein, successful utilization of non-covalent N-heterocyclic carbene (NHC) catalysis toward asymmetric aminative dearomatization naphthols is presented. The NHC-catalyzed process offers enantioselective synthesis cyclic enones possessing a nitrogen-containing α-quaternary stereocenter. reaction applies to various functionalized substrates including acid-labile groups and shown be scalable. Substrate activation via an O-H···NHC hydrogen-bonding interaction suggested based on the results obtained in mechanistic studies.

Language: Английский

Citations

17
Catalytic asymmetric dearomatization of phenols via divergent intermolecular (3 + 2) and alkylation reactions DOI Creative Commons
Xiang Gao,

Tian‐Jiao Han,

Beibei Li

et al.

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Aug. 25, 2023

Abstract The catalytic asymmetric dearomatization (CADA) reaction has proved to be a powerful protocol for rapid assembly of valuable three-dimensional cyclic compounds from readily available planar aromatics. In contrast the well-studied indoles and naphthols, phenols have been considered challenging substrates intermolecular CADA reactions due combination strong aromaticity potential regioselectivity issue over multiple nucleophilic sites (O, C2 as well C4). Reported herein are chiral phosphoric acid-catalyzed divergent common with azoalkenes, which deliver tetrahydroindolone cyclohexadienone products bearing an all-carbon quaternary stereogenic center in good yields excellent ee values. Notably, simply adjusting temperature leads chemo-divergent (3 + 2) alkylation reactions. Moreover, stereo-divergent synthesis four possible stereoisomers kind achieved via changing sequence catalyst enantiomers.

Language: Английский

Citations

17
Catalytic Asymmetric Dearomatization of 2,3-Disubstituted Indoles by a [4 + 2] Cycloaddition Reaction with In Situ Generated Vinylidene ortho-Quinone Methides: Access to Polycyclic Fused Indolines DOI

Amit Shikari,

Chandrakanta Parida, Subhas Chandra Pan

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: 26(24), P. 5057 - 5062

Published: March 15, 2024

A protocol of enantioselective dearomatization 2,3-disubstituted indoles by an organocatalytic intermolecular (4 + 2) cycloaddition reaction with in situ generated vinylidene ortho-quinone methide has been documented. wide range polycyclic 2,3-fused indolines containing vicinal quaternary carbon stereocenters was readily prepared high yields and excellent diastereo- enantioselectivities.

Language: Английский

Citations

6
Dearomatizing [4+1] Spiroannulation of Naphthols: Discovery of Thermally Activated Delayed Fluorescent Materials DOI

Wenbo Liang,

Yudong Yang,

Mufan Yang

et al.

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(7), P. 3493 - 3497

Published: Oct. 21, 2020

Abstract Disclosed here is a palladium‐catalyzed direct [4+1] spiroannulation of ortho ‐C−H bonds naphthols with cyclic diaryliodonium salts to construct spirofluorenyl naphthalenones (SFNP) under mild reaction conditions. This directly transforms the hydroxy group into carbonyl group, and also tolerates reactive functional groups such as halo groups, which provide an opportunity rapidly assemble structurally new thermally activated delayed fluorescent (TADF) materials that feature adjacent unit acceptor. As illustrated example, OLED device utilizing assembled DMAC‐SFNP host material exhibits low turn‐on voltage 2.5 V ultra‐high external quantum efficiency 32.2 %. work provides inspiration for TADF materials, displays potential C−H activation synthetic strategy innovation optoelectronic materials.

Language: Английский

Citations

41
Chemo-, regio- and enantioselective dearomative (3+2) reaction of non-functionalized 1-naphthols DOI Creative Commons
Guang‐Jian Mei, Yixin Luo, Wai Lean Koay

et al.

Chem Catalysis, Journal Year: 2022, Volume and Issue: 2(2), P. 386 - 399

Published: Jan. 21, 2022

Language: Английский

Citations

24
Organocatalytic Asymmetric Dearomative Spirocyclization/Oxa-Michael Addition Sequence: Synthesis of Polycyclic Tetralones DOI

Ramji Meher,

Subhas Chandra Pan

Organic Letters, Journal Year: 2024, Volume and Issue: 26(15), P. 3179 - 3183

Published: April 3, 2024

Herein, an organocatalytic asymmetric dearomative spirocyclization/oxa-Michael addition sequence with a newly designed substrate having two naphthol motifs has been developed. The reaction proceeds through in situ chiral vinylidene ortho-quinone methide (VQM) intermediate formation, spirocyclization of naphthol, and oxa-Michael reaction. densely functionalized tetralone products were formed high yields diastereo- enantioselectivities.

Language: Английский

Citations

5
Radical‐Mediated Non‐Dearomative Strategies in Construction of Spiro Compounds DOI
Robert Pawłowski, Patryk Skórka, M. Stodulski

et al.

Advanced Synthesis & Catalysis, Journal Year: 2020, Volume and Issue: 362(21), P. 4462 - 4486

Published: Aug. 29, 2020

Abstract In recent years, spirocyclic compounds have attracted a significant interest in medicinal chemistry due to their considerable biological activities. The general and widely used concept for compound synthesis is related with dearomatization of starting material. However, most the libraries prepared using this comprise structure similarity. Therefore, preparation structurally distinct comprising varied functionality requires different approaches that includes non‐dearomative pathways. given review advance spirocycles via radical‐mediated strategies discussed. context, application radical initiators or photoredox catalysis described. variety presented examples indicates high potential visible‐light‐induced methodologies synthesis, which can act as very efficient green alternative known procedures, offering mild reaction conditions functional group tolerance. magnified image

Language: Английский

Citations

36
Catalytic Asymmetric Dearomative Arylation of 2‐Naphthols Enabled by o‐Quinone Diimides DOI

Yuan‐Yang Li,

Fu‐Yuan Yang,

Meng‐Yuan Wu

et al.

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(20), P. 4238 - 4243

Published: March 16, 2024

Abstract The catalytic asymmetric dearomative arylation of 2‐naphthols enabled by the unconventional reactivity o ‐quinone diimides, i. e. 1,4‐conjugate addition on quinone sp 2 hybridized carbon, has been established. Under catalysis chiral phosphoric acid, various cyclohexaenones bearing an all‐carbon quaternary stereocenter have prepared with excellent yields and enantioselectivities.

Language: Английский

Citations

4