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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Recent advances in the application of Diels–Alder reactions involving o-quinodimethanes, aza-o-quinone methides and o-quinone methides in natural product total synthesis

Chemical Society Reviews, Journal Year: 2018, Volume and Issue: 47(21), P. 7926 - 7953

Published: Jan. 1, 2018

In recent decades, transient and highly reactive ortho-quinodimethanes (o-QDMs), ortho-quinone methides (o-QMs) aza-ortho-quinone (aza-o-QMs) have attracted much attention been extensively studied applied in organic synthesis, especially natural product total synthesis. This review summarizes advances Diels-Alder reactions involving situ-generated o-QDMs, o-QMs aza-o-QMs, highlighting the power potential of this strategy synthesis An overview methods for generating these intermediates is also available.

Language: Английский

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Iridium-Catalyzed Asymmetric Synthesis of Functionally Rich Molecules Enabled by (Phosphoramidite,Olefin) Ligands

Accounts of Chemical Research, Journal Year: 2019, Volume and Issue: 52(9), P. 2657 - 2672

Published: June 19, 2019

ConspectusThe catalytic, asymmetric synthesis of complex molecules has been a core focus our research program for some time because developments in the area can have an immediate impact on identification novel strategies value-added molecules. In concert with this central interest, we emphasized design ligand scaffolds as tactic to discover and develop chemistry overcome well-recognized synthetic challenges. Based group's work chiral pool-derived diolefin ligands, designed implemented class hybrid (phosphoramidite,olefin) which combines properties both phosphoramidite olefin motifs impact, fine-tune, even override inherent reactivity metal center. Specifically, utilized these unique modifying ligands address several recognized limitations field iridium-catalyzed, allylic substitution. The methods documented typically employ branched, unprotected alcohols substrates obviate need rigorous exclusion air moisture.Following Takeuchi's seminal report demonstrating high aptitude Ir(I)-phosphite catalysts branch-selective substitution, concerted efforts from numerous laboratories led broadening utility reaction class. first section Account outlines process leading discovery unprecedented its validation iridium-catalyzed amination alcohols. This continues involving heteroatom-based nucleophiles within inter- intramolecular etherification, thioetherification spiroketalization processes. second highlights use readily available carbon possessing sp, sp2, sp3 hybridization series enantioselective carbon–carbon bond-forming reactions. We describe how alkylzinc, allylsilane, classes organotrifluoroborate be coupled enantioselectively enable construction key including 1,5-dienes, 1,4-dienes, 1,4-enynes. Since electronic steric renders (η3-allyl)-Ir(III) intermediate highly electrophilic, weak such alkyl olefins used. also show that more nucleophilic alkene enamines situ generated ketene acetals smoothly participate substitution reactions yield valuable piperidines γ,δ-unsaturated esters, respectively.The concept stereodivergent dual catalysis, synergistically amine catalysis iridium furnish α-allylated aldehydes containing two independently controllable stereocenters is then discussed. enabled independent, stereoselective all four possible product stereoisomers single set starting materials, was highlighted Δ9-tetrahydrocannabinol. concludes overview organometallic mechanistic studies regarding relevant intermediates catalytic cycle These allowed us better understand origin characteristics exhibited by catalyst comparison related systems.

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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Enantioselective formation of quaternary carbon stereocenters in natural product synthesis: a recent update

Natural Product Reports, Journal Year: 2019, Volume and Issue: 37(2), P. 276 - 292

Published: Sept. 13, 2019

The enantioselective formation of quaternary carbon stereocenters in complex natural product synthesis the latest six years is reviewed, with particular emphasis on analysis stereochemical model each transformation.

Language: Английский

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Recent Developments in Transition Metal‐Catalyzed Dearomative Cyclizations of Indoles as Dipolarophiles for the Construction of Indolines

Advanced Synthesis & Catalysis, Journal Year: 2018, Volume and Issue: 361(3), P. 405 - 425

Published: Aug. 20, 2018

Abstract Fused polycyclic indoline skeletons are found in many natural products and bioactive molecules. Several approaches, including dearomative cyclization of functionalized indoles, have been developed for the rapid synthesis these skeletons. As a result extensive research over past few decades, numerous elegant efficient protocols transition metal‐catalyzed indoles to afford indolines reported, recent developments this area discussed detail review. magnified image

Language: Английский

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Progress in organocatalytic asymmetric (4+3) cycloadditions for the enantioselective construction of seven-membered rings

Science China Chemistry, Journal Year: 2023, Volume and Issue: 66(4), P. 966 - 992

Published: Feb. 15, 2023

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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Visible‐Light‐Driven Aza‐ortho‐quinone Methide Generation for the Synthesis of Indoles in a Multicomponent Reaction

Angewandte Chemie International Edition, Journal Year: 2017, Volume and Issue: 56(32), P. 9527 - 9531

Published: June 21, 2017

A visible-light-driven radical-mediated strategy for the in situ generation of aza-ortho-quinone methides from 2-vinyl-substituted anilines and alkyl radical precursors is described. This process enables an efficient multicomponent reaction 2-vinylanilines, halides, sulfur ylides, has a wide substrate scope good functional group tolerance. Treatment cycloaddition products with base leads to densely functionalized indoles single-flask operation.

Language: Английский

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Synergetic iridium and amine catalysis enables asymmetric [4+2] cycloadditions of vinyl aminoalcohols with carbonyls

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

Published: June 20, 2019

Abstract Catalytic asymmetric cycloadditions via transition-metal-containing dipolar intermediates are a powerful tool for synthesizing chiral heterocycles. However, within the field of palladium catalysis, compared with well-developed normal electron-demand electrophilic dipolarophiles, general strategy inverse ones nucleophilic dipolarophiles remains elusive, due to inherent linear selectivity in key palladium-catalyzed intermolecular allylations. Herein, based on switched regioselectivity iridium-catalyzed allylations, we achieved two [4+2] vinyl aminoalcohols aldehydes and β,γ-unsaturated ketones through synergetic iridium amine catalysis. The activation by catalysts carbonyls provide foundation subsequent resulting iridium-containing 1,4-dipoles (di)enamine dipolarophiles. former provides straightforward route diverse set enantio-enriched hydroquinolines bearing quaternary stereocenters, later represent an enantio- diastereodivergent synthesis hydroquinolines.

Language: Английский

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