Iridium-Catalyzed Asymmetric Allylic Substitution Reactions

Chemical Reviews, Journal Year: 2018, Volume and Issue: 119(3), P. 1855 - 1969

Published: Dec. 24, 2018

In this review, we summarize the origin and advancements of iridium-catalyzed asymmetric allylic substitution reactions during past two decades. Since first report in 1997, Ir-catalyzed have attracted intense attention due to their exceptionally high regio- enantioselectivities. been significantly developed recent years many respects, including ligand development, mechanistic understanding, substrate scope, application synthesis complex functional molecules. an explicit outline ligands, mechanism, scope nucleophiles, applications is presented.

Language: Английский

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Intermolecular Metal-Catalyzed Reductive Coupling of Dienes, Allenes, and Enynes with Carbonyl Compounds and Imines

Chemical Reviews, Journal Year: 2018, Volume and Issue: 118(12), P. 6026 - 6052

Published: June 13, 2018

Metal-catalyzed reductive coupling has emerged as an alternative to the use of stoichiometric organometallic reagents in increasingly diverse range carbonyl and imine additions. In this review, diene, allene, enyne pronucleophiles intermolecular couplings are surveyed, along with related hydrogen autotransfer processes.

Language: Английский

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CuH-Catalyzed Olefin Functionalization: From Hydroamination to Carbonyl Addition

Accounts of Chemical Research, Journal Year: 2020, Volume and Issue: 53(6), P. 1229 - 1243

Published: May 13, 2020

ConspectusIn organic synthesis, ligand-modified copper(I) hydride (CuH) complexes have become well-known reagents and catalysts for selective reduction, particularly toward Michael acceptors carbonyl compounds. Recently, our group others found that these undergo migratory insertion (hydrocupration) with relatively unactivated electronically unpolarized olefins, producing alkylcopper intermediates can be leveraged to forge a variety of useful bonds. The resulting formal hydrofunctionalization reactions formed the basis resurgence research in CuH catalysis. This Account chronicles development this concept group, highlighting its origin context asymmetric hydroamination, evolution more general C–X bond-forming reactions, applications addition olefin-derived nucleophiles derivatives.Hydroamination, an olefin into N–H bond amine, is process significant academic industrial interest, due potential transform widely available alkenes alkynes valuable complex amines. We developed polarity-reversed strategy catalytic enantioselective hydroamination relying on reaction olefins generate chiral organocopper intermediates, which are intercepted by electrophilic amine reagents. By engineering auxiliary ligand, electrophile, conditions, scope method has since been extended include many types including challenging internal olefins. Further, expanded enable synthesis primary, secondary, tertiary amines as well amides, N-alkylated heterocycles, anilines. All exhibit high regio- stereoselectivity and, mild conditions required, excellent tolerance heterocycles polar functional groups.Though generation species from was originally devised means solve problem, we soon could react efficiently unexpectedly broad range electrophiles, alkyl halides, silicon reagents, arylpalladium species, derivatives. ability function precursors nucleophilic proved advantageous because it overcomes disadvantages associated traditional organometallic removing need pregeneration nucleophile separate operation, CuH-catalyzed feature improved step economy, enhanced tolerance, catalyst control over stereoselectivity. Following paradigm, feedstock such allene, butadiene, styrene employed alkylation ketones, imines, aldehydes.

Language: Английский

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Diastereoselective Allylation of Aldehydes by Dual Photoredox and Chromium Catalysis

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(40), P. 12705 - 12709

Published: Sept. 14, 2018

Herein, we report the redox-neutral allylation of aldehydes with readily available electron-rich allyl (hetero-) arenes, β-alkyl styrenes and allyl-diarylamines. This process was enabled by combination photoredox chromium catalysis, which allowed a range homoallylic alcohols to be prepared high levels selectivity for anti diastereomer. Mechanistic investigations support formation an intermediate from allylic C(sp3)–H bonds thus significantly extends scope venerable Nozaki–Hiyama–Kishi reaction.

Language: Английский

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A Radical Approach to Anionic Chemistry: Synthesis of Ketones, Alcohols, and Amines

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(16), P. 6726 - 6739

Published: April 3, 2019

Historically accessed through two-electron, anionic chemistry, ketones, alcohols, and amines are of foundational importance to the practice organic synthesis. After placing this work in proper historical context, Article reports development, full scope, a mechanistic picture for strikingly different way forging such functional groups. Thus, carboxylic acids, once converted redox-active esters (RAEs), can be utilized as formally nucleophilic coupling partners with other derivatives (to produce ketones), imines benzylic amines), or aldehydes alcohols). The reactions uniformly mild, operationally simple, and, case ketone synthesis, broad scope (including several applications simplification synthetic problems parallel synthesis). Finally, an extensive study synthesis is performed trace elementary steps catalytic cycle provide end-user clear understandable rationale selectivity, role additives, underlying driving forces involved.

Language: Английский

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Selective Hydrogen Atom Abstraction through Induced Bond Polarization: Direct α‐Arylation of Alcohols through Photoredox, HAT, and Nickel Catalysis

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 57(19), P. 5369 - 5373

Published: Feb. 28, 2018

The combination of nickel metallaphotoredox catalysis, hydrogen atom transfer and a Lewis acid activation mode, has led to the development an arylation method for selective functionalization alcohol α-hydroxy C-H bonds. This approach employs zinc-mediated deprotonation activate bonds while simultaneously suppressing C-O bond formation by inhibiting alkoxide species. use Zn-based acids also deactivates other hydridic such as α-amino α-oxy facilitates rapid access benzylic alcohols, important motif in drug discovery. A 3-step synthesis Prozac exemplifies utility this new method.

Language: Английский

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Catalytic Enantio- and Regioselective Addition of Nucleophiles in the Intermolecular Hydrofunctionalization of 1,3-Dienes

ACS Catalysis, Journal Year: 2019, Volume and Issue: 10(2), P. 1060 - 1076

Published: Dec. 12, 2019

Catalytic enantioselective synthesis of small-molecule building blocks with allylic stereogenic centers is an important objective in organic synthesis, but preparing this motif wherein the adjacent olefin 1,2-disubstituted a single step tremendous challenge. Late-transition-metal-catalyzed intermolecular couplings nucleophiles and 1,3-dienes hydrofunctionalization reactions have quickly emerged as compelling approach to these related compounds. In Perspective, we illustrate how diene hydrofunctionalizations provided avenue complex, highly desirable chemical space that not readily accessed by other technologies. We also aim provide some insight into varying mechanistic pathways nuances myriad help inform future reaction catalyst design.

Language: Английский

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Catalytic asymmetric allylation of aldehydes with alkenes through allylic C(sp³)–H functionalization mediated by organophotoredox and chiral chromium hybrid catalysis

Chemical Science, Journal Year: 2019, Volume and Issue: 10(12), P. 3459 - 3465

Published: Jan. 1, 2019

We have developed a catalytic asymmetric nucleophilic allylation of aldehydes using simple alkenes as pronucleophiles without relying on stoichiometric metals.

Language: Английский

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Visible light-induced direct α C–H functionalization of alcohols

Nature Communications, Journal Year: 2019, Volume and Issue: 10(1)

Published: Jan. 28, 2019

Abstract Considering the synthetic value of introducing active alcoholic hydroxyl group, developing C–H functionalization alcohols is significance. Herein, we present a photochemical method that under visible light irradiation, selectfluor can effectively promote oxidative cross-coupling between and heteroarenes without external photocatalysis, achieving selective α sp 3 arylation alcohol, even in presence ether. The N-F activation blue LEDs irradiation evidenced by electron paramagnetic resonance (EPR) study, which key process for alcohols. observed reactivity may have significant implications chemical transformations.

Language: Английский

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Dialkylation of 1,3-Dienes by Dual Photoredox and Chromium Catalysis

ACS Catalysis, Journal Year: 2019, Volume and Issue: 10(2), P. 1621 - 1627

Published: Dec. 18, 2019

The direct conversion of feedstock chemicals into value-added products is broad interest in chemical research. Herein, we present a regioselective and diastereoselective three-component dialkylation 1,3-dienes with Hantzsch esters aldehydes for the synthesis homoallylic alcohols. reaction enabled by dual photoredox chromium catalysis can also be performed enantioselectively employing chromium-bisoxazoline complexes.

Language: Английский

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