The Selective N‐Functionalization of Indoles via aza‐Michael Addition in the Ligand Sphere of a Chiral Nickel(II) Complex: Asymmetric Synthesis of (S)‐1H‐Indole‐Alanine Derivatives DOI
Vladimir A. Larionov,

Tat’yana F. Savel’yeva,

Michael G. Medvedev

и другие.

European Journal of Organic Chemistry, Год журнала: 2019, Номер 2019(22), С. 3699 - 3703

Опубликована: Май 8, 2019

The selective addition of electrophilic C=C double bonds to the N–H bond indoles is a challenging task due high nucleophilicity at their C3‐position. Herein, we report successful intermolecular N ‐functionalization various via aza ‐Michael dehydroalanine Schiff base, which takes place in ligand sphere chiral Ni II complex presence sodium hydride. resulting hydroaminated complexes were isolated 55–82 % yields with excellent diastereoselectivity ( dr > 99:1) (8 examples). And actual products interest, namely S )‐2‐amino‐3‐(1 H ‐indol‐1‐yl)propanoic acids, subsequently released from aqueous HCl treatment and enantioselectivity (> 99 ee ). auxiliary [( )‐BPB = )‐2‐( ‐benzylprolyl)aminobenzophenone] ions can be easily recovered after acidic cleavage step reused for synthesis starting complex. Moreover, indole′s preference nucleophilic attack its N1‐ over C3‐position was rationalized by DFT calculations.

Язык: Английский

NHC-Catalyzed Generation of α,β-Unsaturated Acylazoliums for the Enantioselective Synthesis of Heterocycles and Carbocycles DOI

Santigopal Mondal,

Santhivardhana Reddy Yetra, Subrata Mukherjee

и другие.

Accounts of Chemical Research, Год журнала: 2019, Номер 52(2), С. 425 - 436

Опубликована: Янв. 17, 2019

ConspectusThis Account is aimed at highlighting the recent developments in N-heterocyclic carbene (NHC)-catalyzed generation of α,β-unsaturated acylazolium intermediates and their subsequent reactivity with (bis)nucleophiles thereby shedding light on power this NHC-bound intermediate organocatalysis. This key can be generated by addition NHCs to aldehyde or acid derivatives. A wide variety bisnucleophiles add across acylazoliums form various five six-membered heterocycles carbocycles. Moreover, suitably substituted nucleophiles result valuable products following cascade processes. Employing chiral process enantioselective synthesis compounds.In 2013, we developed a unified strategy for dihydropyranones dihydropyridinones NHC-catalyzed formal [3 + 3] annulation 2-bromoenals readily available 1,3-dicarbonyl compounds primary vinylogous amides. reaction takes place under mild conditions low catalyst loading. Interestingly, employing enolizable aldehydes as afforded 4,5-disubstituted spite competing benzoin/Stetter pathways. use cyclic such 4-hydroxy coumarin/pyrazolone coumarin/pyrazole-fused dihydropyranones. In addition, 2] spiro γ-butyrolactones was demonstrated using 3-hydroxy oxindoles bisnucleophile.The interception malonic ester derivatives having γ-benzoyl group resulted functionalized cyclopentenes via involving Michael-intramolecular aldol-β-lactonization-decarboxylation sequence. The β-ketoamides coupling partner catalytically spiro-glutarimide proceeds Michael addition-intramolecular amidation pathway.We have recently tricyclic δ-lactones three contiguous stereocenters enals dinitrotoluene bearing electron-withdrawing groups, oxidative conditions. atom-economic Michael/Michael/lactonization sequence tolerating range functional groups. technique also used N–H functionalization indoles pyrroloquinolines aza-Michael/Michael/lactonization sequence.The α-arylidene pyrazolinones tandem dienolate/enolates combined pyrazolone-fused spirocyclohexadienones. Michael/spiroannulation/dehydrogenation afford spirocyclic an all-carbon quaternary stereocenter.It reasonable believe that chemistry acylazoliums, through NHCs, will continue flourish lead amazing results. Future challenges area include applications biologically active natural drugs.

Язык: Английский

Процитировано

326
Advances in organocatalytic asymmetric reactions of vinylindoles: powerful access to enantioenriched indole derivatives DOI

Man‐Su Tu,

Ke-Wei Chen, Ping Wu

и другие.

Organic Chemistry Frontiers, Год журнала: 2021, Номер 8(11), С. 2643 - 2672

Опубликована: Янв. 1, 2021

This review summarizes advances in vinylindole-based organocatalytic asymmetric reactions since 2008 and includes the applications of some methodologies total synthesis natural products, points out remaining challenges this research area.

Язык: Английский

Процитировано

92
Imines as acceptors and donors in N-heterocyclic carbene (NHC) organocatalysis DOI
Tamal Das, Akkattu T. Biju

Chemical Communications, Год журнала: 2020, Номер 56(61), С. 8537 - 8552

Опубликована: Янв. 1, 2020

The synthetic potential of imines as electrophiles or a source nucleophilic coupling partner in N-heterocyclic carbene (NHC) catalysis for the synthesis various nitrogen heterocycles and functionalized amines is highlighted this Feature Article. Electrophilic are suitable candidates intercepting NHC-derived acyl anions, homoenolate equivalents, (di)enolates α-amino ketones variety lactam derivatives. Moreover, enamines generated from bearing α-hydrogen could be trapped with α,β-unsaturated acylazoliums dihydropyridinones. NHCs also useful umpolung generation aza-Breslow intermediates thus leading to indoles, quinolines, dihydroquinoxalines etc. A concise account diverse reactivity NHC has been presented.

Язык: Английский

Процитировано

83
NHC-Catalyzed [3 + 3] Annulation of Thioamides and Modified Enals for the Enantioselective Synthesis of Functionalized Thiazinones DOI

Arghya Ghosh,

Soumen Barik,

Akkattu T. Biju

и другие.

Organic Letters, Год журнала: 2019, Номер 21(21), С. 8598 - 8602

Опубликована: Окт. 16, 2019

N-Heterocyclic carbene (NHC)-catalyzed [3 + 3] annulation of thioamides with modified enals allowing the enantioselective synthesis functionalized 1,3-thiazin-4-ones is reported. The NHC generated from chiral triazolium salt was optimal and reaction initiated by thia-Michael addition to catalytically α,β-unsaturated acylazolium intermediates derived 2-bromoenals, followed intramolecular cyclization. This operationally simple procedure offers a straightforward rapid access target compounds in moderate good yields enantiomeric ratio values.

Язык: Английский

Процитировано

59
NHC-catalyzed covalent activation of heteroatoms for enantioselective reactions DOI Creative Commons
Runjiang Song, Zhichao Jin, Yonggui Robin

и другие.

Chemical Science, Год журнала: 2021, Номер 12(14), С. 5037 - 5043

Опубликована: Янв. 1, 2021

Covalent activation of heteroatoms enabled by N-heterocyclic carbene (NHC) organic catalysts for enantioselective reactions is evaluated and summarized in this review.

Язык: Английский

Процитировано

55
Recent Advances in Catalytic Asymmetric Aza‐Michael Addition Triggered Cascade Reactions DOI
Yong‐Xing Song, Da‐Ming Du

Advanced Synthesis & Catalysis, Год журнала: 2021, Номер 363(20), С. 4667 - 4694

Опубликована: Авг. 28, 2021

Abstract As an important branch of the Michael addition reaction, aza‐Michael cascade reaction has been developed rapidly in recent years. This is because serves as method for effectively constructing functionalized C−N bonds, which can be widely used synthesis chiral drugs and their intermediates natural products. Given importance this topic, review highlights developments triggered reactions asymmetric synthesis, including aza‐Michael/Michael, aza‐Michael/Aldol, aza‐Michael/Henry, aza‐Michael/hemiacetal, aza‐Michael/Mannich, aza‐Michael/alkylation, aza‐Michael/cyclization, aza‐Michael/ring‐opening, aza‐Michael‐IED/HAD, aza‐Michael/INCR, aza‐Michael/1,6‐conjugate reactions. In paper, mechanism derivatization experiments different are timely introduced to provide a more comprehensive theoretical basis subsequent studies. magnified image

Язык: Английский

Процитировано

51
Carbene‐Catalyzed Enantioselective Hydrophosphination of α‐Bromoenals to Prepare Phosphine‐Containing Chiral Molecules DOI

Rakesh Maiti,

Jia‐Lei Yan, Xing Yang

и другие.

Angewandte Chemie International Edition, Год журнала: 2021, Номер 60(51), С. 26616 - 26621

Опубликована: Окт. 2, 2021

Disclosed herein is the first carbene-organocatalyzed asymmetric addition of phosphine nucleophiles to in situ generated α,β-unsaturated acyl azolium intermediates. Our reaction enantioselectively constructs carbon-phosphine bonds and prepares chiral phosphines with high optical purities. The products are suitable for transforming ligands or catalysts applications catalysis. diarylalkyl trialkyl from our catalytic reactions, air-sensitive reactive nature, can be trapped (and stored) their sulfur-oxidized form operational simplicities.

Язык: Английский

Процитировано

44
Enantioselective Indole N–H Functionalization Enabled by Addition of Carbene Catalyst to Indole Aldehyde at Remote Site DOI
Xing Yang, Guoyong Luo, Liejin Zhou

и другие.

ACS Catalysis, Год журнала: 2019, Номер 9(12), С. 10971 - 10976

Опубликована: Окт. 29, 2019

An enantioselective functionalization of the indole NH group is developed. The reaction stereoselectivity controlled by an N-heterocyclic carbene catalyst that adds to aldehyde moiety at C7-carbon indole. participating in carbene-catalyzed part heteroaromatic rings substrate. Our reactions afford multicyclic products bearing pyrroloquinazoline or oxazinoindole scaffolds widely present bioactive molecules. study will encourage further exploration aromatic molecules and asymmetric transformation heteroatoms various functional

Язык: Английский

Процитировано

44
Catalytic, Enantioselective C2-Functionalization of 3-Aminobenzofurans Using N-Heterocyclic Carbenes DOI

Shilpa Barik,

Sayan Shee,

Arghya Ghosh

и другие.

Organic Letters, Год журнала: 2020, Номер 22(10), С. 3865 - 3869

Опубликована: Май 4, 2020

N-Heterocyclic carbene catalyzed enantioselective functionalization of 3-aminobenzofurans at the C2-position was realized using 2-bromoenals as coupling partner. The reaction proceeds via generation chiral α,β-unsaturated acylazoliums and follows an aza-Claisen rearrangement. initially formed dihydropyridinone undergoes ring-opening by Mg to afford δ-amino acid derivatives. worked with 3-aminobenzothiophenes well, C2-alkylated products were in moderate high yields selectivity.

Язык: Английский

Процитировано

43
Phosphine-Mediated Sequential [2+4]/[2+3] Annulation to Construct Pyrroloquinolines DOI

Junhui Lin,

Yannan Zhu, Wei Cai

и другие.

Organic Letters, Год журнала: 2022, Номер 24(8), С. 1593 - 1597

Опубликована: Фев. 18, 2022

A domino [2+4]/[2+3] sequential annulation reaction of MBH carbonates with N-unprotected indoles has been developed to provide various pyrroloquinoline derivatives in ≤94% yield and 20:1 dr. The could be either mediated by stoichiometric PCy3 or catalyzed R3PO via PIII/PV═O redox cycling the presence phenylsilane. This method assembles polycyclic 1,7-fused one step diastereoselectively.

Язык: Английский

Процитировано

28