Phosphine‐Catalyzed [4+1] Cycloadditions of Allenes with Methyl Ketimines, Enamines, and a Primary Amine DOI

Ze‐Hun Cao,

Yu‐Hao Wang,

Subarna Jyoti Kalita

et al.

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(5), P. 1884 - 1890

Published: Nov. 20, 2019

Abstract Unprecedented phosphine‐catalyzed [4+1] cycloadditions of allenyl imides have been discovered using various N‐based substrates including methyl ketimines, enamines, and a primary amine. These transformations provide one‐pot access to cyclopentenoyl enamines imines, or (chiral) γ‐lactams through two geminal C−C bond C−N formations, respectively. Several P‐based key intermediates 1,4‐(bis)electrophilic α,β‐unsaturated ketenyl phosphonium species detected by 31 P NMR HRMS analyses, which shed light on the postulated catalytic cycle. The synthetic utility this new chemistry has demonstrated gram‐scaling up reaction as well regioselective hydrogenation double condensation form cyclopentanoyl fused pyrazole building blocks,

Language: Английский

Advances in Catalytic Asymmetric Dearomatization DOI Creative Commons
Chao Zheng, Shu‐Li You

ACS Central Science, Journal Year: 2021, Volume and Issue: 7(3), P. 432 - 444

Published: Feb. 22, 2021

Asymmetric catalysis has been recognized as the most enabling strategy for accessing chiral molecules in enantioenriched forms. Catalytic asymmetric dearomatization is an emerging and dynamic research subject catalysis, which received considerable attention recent years. The direct transformations from readily available aromatic feedstocks to structurally diverse three-dimensional polycyclic make catalytic reactions of broad interest both organic synthesis medicinal chemistry. However, inherent difficulty disruption aromaticity demands a large energy input during process, might be incompatible with conditions generally required by catalysis. In this Outlook, we will discuss representative strategies examples various compounds try convince readers that overcoming above obstacles, could advance chemical sciences many respects.

Language: Английский

Citations

302
Phosphorus-Based Catalysis DOI Creative Commons
Changmin Xie, Andrew J. Smaligo,

Xian-Rong Song

et al.

ACS Central Science, Journal Year: 2021, Volume and Issue: 7(4), P. 536 - 558

Published: March 16, 2021

Phosphorus-based organocatalysis encompasses several subfields that have undergone rapid growth in recent years. This Outlook gives an overview of its various aspects. In particular, we highlight key advances three topics: nucleophilic phosphine catalysis, organophosphorus catalysis to bypass oxide waste, and compound-mediated single electron transfer processes. We briefly summarize five additional chiral phosphoric acid Lewis base iminophosphorane super phosphonium salt phase frustrated pair catalysis. Although it is not catalytic nature, also discuss novel discoveries are emerging phosphorus(V) ligand coupling. conclude with some ideas about the future

Language: Английский

Citations

236
Progresses in organocatalytic asymmetric dearomatization reactions of indole derivatives DOI Open Access

Feng‐Tao Sheng,

Jing‐Yi Wang, Wei Tan

et al.

Organic Chemistry Frontiers, Journal Year: 2020, Volume and Issue: 7(23), P. 3967 - 3998

Published: Jan. 1, 2020

This review summarizes the progresses in organocatalytic asymmetric dearomatization reactions of indole derivatives and their applications total synthesis natural products, gives some insights into challenging issues this research field.

Language: Английский

Citations

210
Recent advances in phosphine catalysis involving γ-substituted allenoates DOI
Er‐Qing Li, You Huang

Chemical Communications, Journal Year: 2019, Volume and Issue: 56(5), P. 680 - 694

Published: Dec. 10, 2019

Organophosphine catalysis of allenoates has doubtlessly been one the most ideal and powerful synthetic strategies for generation highly functionalized carbo-/hetero-cycle motifs, which are important structural motifs in biologically active natural products pharmaceuticals. Because their diverse amazing reactivity, chemists usually pay more attention to study 2,3-butadienoates α-substituted allenoates. More recently, there is a growing interest phosphine γ-substituted allenoates, have low reactivity selectivity. This feature article will describe selected examples organophosphine with wide range electrophiles.

Language: Английский

Citations

167
Transformations of Modified Morita‐Baylis‐Hillman Adducts from Isatins Catalyzed by Lewis Bases DOI

Zhi‐Chao Chen,

Zhi Chen, Wei Du

et al.

The Chemical Record, Journal Year: 2019, Volume and Issue: 20(6), P. 541 - 555

Published: Oct. 14, 2019

The development of synthetic protocols to access architectures with broad structural and functional diversity from readily available starting materials is very attractive in both organic medicinal chemistry fields. Toward this objective, the multifunctional isatin-derived Morita-Baylis-Hillman (MBH) adducts provide opportunities construct a variety complex scaffolds containing "privileged" oxindole motif through several catalytic pathways. By forming ammonium or phosphonium salts Lewis bases, MBH can undergo allylic substitutions range nucleophiles, usually SN 2'-SN 2' pattern. Besides, assisted by Brønsted corresponding onium be converted into ylide intermediates, which various annulation reactions even 1,3-difunctionalizations. Moreover, recent cooperative catalysis bases transition metal complexes further puts forward application adducts. This tutorial review covers significant transformations adducts, mostly an asymmetric version, catalyzed over past decade.

Language: Английский

Citations

115
Recent Advances in the Catalytic Functionalization of “Electrophilic” Indoles DOI

Alessandro Cerveri,

Marco Bandini

Chinese Journal of Chemistry, Journal Year: 2019, Volume and Issue: 38(3), P. 287 - 294

Published: Dec. 12, 2019

When “dark” is bright : the scarcely explored electrophilic profile of indolyl core ( dark‐side ) continues to inspire developments in organic synthesis by means new catalytic methodologies. Recent advancements field enabled molecular diversity and complexity be effectively realized within heterocyclic chemistry.

Language: Английский

Citations

95
π‐Lewis‐Base‐Catalyzed Asymmetric Vinylogous Umpolung Reactions of Cyclopentadienones and Tropone DOI

Xing‐Xing Yang,

Ru‐Jie Yan,

Guang‐Yao Ran

et al.

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(51), P. 26762 - 26768

Published: Oct. 8, 2021

We disclose that the carbonates of 4-hydroxy-2-cyclopentenones can form π-allylpalladium-based 1,2-carbodipoles, which isomerize to interesting η2 -Pd0 -cyclopentadienone complexes. Compared with labile parent cyclopentadienone, HOMO energy related -complex was significantly raised via back-bonding Pd0 as a π-Lewis base, rendering uncoordinated C=C bond an electron-richer dienophile in inverse-electron-demand aza-Diels-Alder-type reactions diverse 1-azadienes. The vinylogous (aza)Morita-Baylis-Hillman or cross Rauhut-Currier addition (imine)carbonyls activated alkenes, respectively, also realized afford chiral [4+2] [2+2] cycloadducts, after trapping re-generated π-allylpalladium species. New C1 -symmetric ligands from simple sources were developed, exhibiting high stereoselectivity even racemic substrates unusual dynamic kinetic resolution process. Besides, tropone could be similarly by complex.

Language: Английский

Citations

56
Site- and Enantioselective Manganese-Catalyzed Benzylic C–H Azidation of Indolines DOI
Min Cao, Hongliang Wang,

Yingang Ma

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(33), P. 15383 - 15390

Published: Aug. 11, 2022

A manganese-catalyzed highly site- and enantioselective benzylic C–H azidation of indolines has been described. The practical method is applicable for a tertiary bond with good functional group tolerance, allowing facile access to structurally diverse azide-containing in high efficiency excellent site-, chemo-, enantioselectivity. generality the was further demonstrated by secondary range indolines. allows straightforwardly enantioselectively install variety nitrogen-based groups bioactive molecules at C3 position indoline frameworks through post-azidation manipulations. Gram-scale synthesis also demonstrated, highlighting synthetic potential method. Mechanistic studies combined experiments computations elucidated reaction mechanism origins stereoselectivity.

Language: Английский

Citations

43
Sadphos as Adaptive Ligands in Asymmetric Palladium Catalysis DOI
Wenbo Li, Junliang Zhang

Accounts of Chemical Research, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 31, 2024

ConspectusPalladium catalysis, as one of the most important strategies in asymmetric synthesis, has continuously attracted attention organic chemists. With development chiral ligands, increasingly challenging reactions and substantial progress catalysis are being realized.Since 2014, we have focused on exploiting a series sulfinamide phosphine ligands called "Sadphos," including Ming-Phos, Xu-Phos, Xiao-Phos, Xiang-Phos, TY-Phos, PC-Phos, GF-Phos, WJ-Phos. These can be easily prepared two to four steps using commercial materials. new types shown remarkable performance transition-metal-catalyzed reactions, especially Pd-catalyzed transformations. X-ray diffraction analysis, mechanistic studies, density functional theory calculations revealed that Sadphos coordinate with Pd0 PdII species Pd0/P, Pd0/P,S, or PdII/P,O modes.This Account summarizes our recent efforts toward palladium-catalyzed enantioselective ligands. were found privileged very crucial promote by increasing reactivity enantioselectivity. Ming-Phos is an effective ligand coupling intramolecular Heck providing highly trisubstituted allenes, axially anilides, gem-diarylmethine silanes, disubstituted dihydroisoquinolinones. Incorporation electron-rich cyclohexyl group moiety afforded which showed unique effect transformations, reductive Heck, dearomative Mizoroki–Heck, tandem Heck/Suzuki coupling, carboiodination, carboamination, cross-coupling reactions. Using similar strategy, synthesized more electron–rich TY-Phos Xiang-Phos bearing t-butyl 1-adamantyl at P atoms, respectively. Regarding stereoelectronic features, these characteristic best choice satisfy requirements fluoroarylation gem-difluoroalkenes, intermolecular α-arylation aldehydes, carboetherification alkenyl oximes, carboheterofunctionalization 2,3-dihydrofurans. Compared aforementioned attractive features high nucleophilicity originating from CH2PPh2 ortho-substituent side aryl ring, presumably responsible for its efficiency. The Pd/Xiao-Phos catalyst system shows good secondary oxides, affording P-stereogenic products multiple molecular skeletons. modification basic backbone introducing xanthene skeleton motivated us design synthesize monophosphines, named PC-Phos GF-Phos. various arylation sulfenate anions, denitrogenative cyclization benzotriazoles, dearomatization indoles. practicability GF-Phos was validated three-component N-tosylhydrazones, halides, terminal alkynes, well N-tosylhydrazones vinyl iodides pendent amines. In addition, ferrocene-derived WJ-Phos employed Suzuki–Miyaura reaction, biaryl monophosphine oxides excellent enantiomeric excesses.

Language: Английский

Citations

15
Dearomative (3 + 2) Cycloadditions of 3-Nitroheteroarenes with Allenyl Sulfones Mediated by Ion Pair Organocatalysis DOI

Léo Birbaum,

Moussa Ndiaye,

Mahmoud Hachem

et al.

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 8, 2025

We report the first example of dearomative (3 + 2) cycloadditions 3-nitro(aza)-indole, -benzofuran, and -benzothiophene derivatives in presence allenyl sulfones, using sulfinate ammonium ion pairs as organocatalytic promoters. The methodology provides a new, facile, efficient protocol for synthesis functionalized 2,3-fused cyclopentannulated indolines dihydrobenzofurans.

Language: Английский

Citations

1