Transition-Metal-Catalyzed Asymmetric Allylic Dearomatization Reactions

Accounts of Chemical Research, Journal Year: 2014, Volume and Issue: 47(8), P. 2558 - 2573

Published: June 18, 2014

ConspectusDearomatization reactions serve as powerful methods for the synthesis of highly functionalized, three-dimensional structures starting with simple planar aromatic compounds. Among processes this type, catalytic asymmetric dearomatization (CADA) are attractive owing to large number compounds that readily available and fact they enable direct access enantiopure polycycles spirocycles, which frequently key structural motifs in biologically active natural products pharmaceuticals. However, a consequence their high stabilities, arenes only difficultly participate take place levels enantioselectivity.Transition-metal-catalyzed allylic substitution have been demonstrated be enantioselective formation C–C C–X (X = O, N, S, etc.) bonds. scope these has explored mainly using soft carbon nucleophiles, some hard nucleophiles such enolates preformed organometallic reagents, heteroatom nucleophiles. Readily accessible rarely used directly reactions.In Account, we present results studies conducted aimed at development transition-metal-catalyzed reactions. By utilizing general process, devised indoles, pyrroles, phenols, naphthols, pyridines, pyrazines, produce various functionalized bearing all-carbon quaternary stereogenic centers straightforward manner. In mechanistic investigations found five-membered spiroindolenines intermediates, undergo stereospecific migration form corresponding tetrahydro-1H-carbazoles upon treatment amount TsOH. It is worth noting no notable loss enantiomeric excess spiroindolenine derivatives takes during rearrangement process intervention "three-center–two-electron"-type transition state, proposal gained support from DFT calculations. Equally intriguing, tuning electronic nature tethers, pyrroles or indoles unprecedented Ir Ru catalyzed intramolecular alkylation promoted dearomatization/migration The operation novel reaction pathway provides additional information leading greater understanding functionalizations indoles. combined effort provide not efficient enantioenriched fused spiro but also strategies field catalysis.

Language: Английский

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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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Catalytic Asymmetric Dearomatization by Transition-Metal Catalysis: A Method for Transformations of Aromatic Compounds

Chem, Journal Year: 2016, Volume and Issue: 1(6), P. 830 - 857

Published: Dec. 1, 2016

Language: Английский

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Stereodivergent α-Allylation of Linear Aldehydes with Dual Iridium and Amine Catalysis

Journal of the American Chemical Society, Journal Year: 2014, Volume and Issue: 136(8), P. 3020 - 3023

Published: Feb. 9, 2014

We describe the fully stereodivergent, dual catalytic α-allylation of linear aldehydes. The reaction proceeds via direct iridium-catalyzed substitution racemic allylic alcohols with enamines generated in situ. use an Ir(P,olefin) complex and a diarylsilyl prolinol ether as catalysts presence dimethylhydrogen phosphate promoter proved to be crucial for achieving high enantio- diastereoselectivity (>99% ee, up >20:1 dr). utility method is demonstrated concise enantioselective synthesis antidepressant (-)-paroxetine.

Language: Английский

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Catalytic asymmetric dearomatization (CADA) reaction-enabled total synthesis of indole-based natural products

Natural Product Reports, Journal Year: 2019, Volume and Issue: 36(11), P. 1589 - 1605

Published: Jan. 1, 2019

The recent enantioselective total syntheses of natural products enabled by catalytic asymmetric dearomatization reactions indole derivatives are presented.

Language: Английский

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Applications of Iridium-Catalyzed Asymmetric Allylic Substitution Reactions in Target-Oriented Synthesis

Accounts of Chemical Research, Journal Year: 2017, Volume and Issue: 50(10), P. 2539 - 2555

Published: Sept. 22, 2017

ConspectusMetal catalyzed allylic substitution is a cornerstone of organometallic and synthetic chemistry. Enantioselective versions have been developed with catalysts derived from transition metals, most notably molybdenum, nickel, ruthenium, rhodium, iridium, palladium, copper. The palladium- the iridium-catalyzed turned out to be particularly versatile in organic synthesis because very broad scope nucleophile great functional group compatibility. Assets reaction are formation branched, chiral products simple monosubstituted substrates, high degrees regio- enantioselectivity, use modular, readily available ligands. possibility carbon, nitrogen, oxygen, sulfur compounds as well fluoride nucleophiles allows wide range building blocks prepared.Our Account begins presentation fundamental schemes We will focus our discussion on reactions promoted by phosphoramidite ligands, though numerous ligands employed. subsequent section presents brief overview mechanism experimental conditions. Two emerged. In type 1 (introduced 1997), linear esters commonly used substrates under basic 2 2007), environmentally friendly branched alcohols can reacted acidic conditions; occasionally, derivatives also applied. A unique feature that highly electrophilic intermediates brought weakly activated alkenes.The text ordered according strategies followed transform desired targets, which natural or drugs. Syntheses starting an intermolecular discussed first. Some fairly complex for example, potent nitric oxide inhibitor (−)-nyasol drug (−)-protrifenbute, synthesized via less than five steps materials.Most targets cyclic compounds. Intermolecular ring closing metathesis powerful strategy their synthesis. Highlights stereodivergent syntheses Δ9-tetrahydrocannabinols (THC), wherein iridium- organocatalysis combined (dual catalysis). combination alkylation Diels–Alder was utilized synthesize ketide apiosporic acid fesoterodine (Toviaz). Sequential amination, hydroboration Suzuki–Miyaura coupling generates enones suitable conjugate addition reactions; this employed variety alkaloids, poison frog alkaloid (+)-cis-195A (pumiliotoxin C).Intramolecular substitutions offer interesting possibilities build up stereochemical complexity short routes. For diastereoselective cyclizations compounds, substrate control overruled catalyst order generate cis- trans-isomers selectively given precursor. This approach prepare piperidine pyrrolidine alkaloids. Finally, polycyclic structures, including structurally unusual indolosesquiterpenoid mycoleptodiscin A, generated diastereo- enantioselectively olefins polyene electron-rich arenes, such indoles, dearomatization reactions.

Language: Английский

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Recent progress in transition-metal-catalyzed enantioselective indole functionalizations

Organic & Biomolecular Chemistry, Journal Year: 2017, Volume and Issue: 15(17), P. 3550 - 3567

Published: Jan. 1, 2017

Numerous efficient synthetic methods for enantioselective indole functionalizations have emerged in recent years. This review summarizes the major achievements transition-metal-catalyzed functionalization reactions since 2010 and focuses on C-C bond formation processes, including alkylations, arylations, cycloaddition reactions, other reactions. It intends to give a compendious overview of significant progress achieved this area.

Language: Английский

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All-carbon quaternary centers in natural products and medicinal chemistry: recent advances

Tetrahedron, Journal Year: 2016, Volume and Issue: 72(43), P. 6729 - 6777

Published: Sept. 13, 2016

Language: Английский

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Synthesis of Cyclobutane-Fused Angular Tetracyclic Spiroindolines via Visible-Light-Promoted Intramolecular Dearomatization of Indole Derivatives

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(6), P. 2636 - 2644

Published: Jan. 17, 2019

An intramolecular dearomatization of indole derivatives based on visible-light-promoted [2+2] cycloaddition was achieved via energy transfer mechanism. The highly strained cyclobutane-fused angular tetracyclic spiroindolines, which were typically unattainable under thermal conditions, could be directly accessed in high yields (up to 99%) with excellent diastereoselectivity (>20:1 dr) mild conditions. method also compatible diverse functional groups and amenable flexible transformations. In addition, DFT calculations provided guidance the rational design substrates deep understanding reaction pathways. This process constituted a rare example functionalization by exploiting visible-light-induced reactivity at excited states.

Language: Английский

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Cascade asymmetric dearomative cyclization reactions via transition-metal-catalysis

Nature Synthesis, Journal Year: 2022, Volume and Issue: 1(3), P. 203 - 216

Published: March 14, 2022

Language: Английский

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