Bimetallic Catalysis in Stereodivergent Synthesis

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(45)

Published: Aug. 2, 2022

Abstract Bimetallic catalysis has emerged as an efficient strategy for the development of new chemical reactions. Importantly, this also provides a simple and powerful platform stereodivergent synthesis, whereby all possible stereoisomers products bearing two stereocenters can be easily prepared from same set starting materials. In Minireview, allylic substitution, propargylic hydrofunctionalization, annulation based on bimetallic been summarized. It is expected that more catalytic systems will developed applied synthesis valuable molecules.

Language: Английский

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Stereodivergent Construction of 1,4‐Nonadjacent Stereocenters via Hydroalkylation of Racemic Allylic Alcohols Enabled by Copper/Ruthenium Relay Catalysis

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(36)

Published: June 28, 2022

An unprecedented hydroalkylation of racemic allylic alcohols and ketimine esters enabled by Cu/Ru relay catalysis has been developed via merging the ruthenium-catalyzed asymmetric borrowing-hydrogen reaction with a copper-catalyzed Michael addition in one-pot procedure. The current method enables efficient preparation highly functionalized δ-hydroxyesters bearing 1,4-nonadjacent stereocenters good yields high levels diastereoselectivity excellent enantioselectivity under mild conditions. full complement four stereoisomers products could be readily accessed orthogonal permutations two chiral metal catalysts. work highlights power for stereodivergent construction that were otherwise inaccessible.

Language: Английский

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Diastereodivergent Aldol‐Type Coupling of Alkoxyallenes with Pentafluorophenyl Esters Enabled by Synergistic Palladium/Chiral Lewis Base Catalysis

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(33)

Published: June 17, 2022

As a fundamental and synthetically useful C-C bond formation reaction, the aldol reaction is one of most versatile transformations in organic synthesis. However, despite extensive research on asymmetric versions unified method for stereoselective access to complementary syn anti diastereomeric products remains be developed. In this study, we developed synergistic palladium/chiral Lewis base system that overcomes inherent diastereoselectivity bias reactions and, as result, allowed us achieve first diastereodivergent coupling alkoxyallenes with pentafluorophenol esters. Computational studies suggest mechanism involving an intermolecular protonative hydropalladation pathway rather than palladium-hydride migratory insertion pathway. The origin stereochemistry catalysis rationalized by DFT calculations.

Language: Английский

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Dual Catalysis in Organic Synthesis: Current Challenges and New Trends

European Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 26(1)

Published: Dec. 9, 2022

Abstract Dual catalysis is one of the most powerful strategies for development chemical reactions in organic synthesis. This strategy can be divided into cooperative catalysis, relay and sequential according to actual mode operation communication between catalysts. In recent years, such has been applied a large number studies since it advantages of: 1) increasing reactivity enabling challenging transformations; 2) offering way controlling stereoselectivity asymmetric reactions, which traditional catalytic systems; 3) catalyze stereodivergent synthesis molecules bearing or more stereocenters from same starting materials. Perspective, intends introduce reader EurJOC special collection on Catalysis , aims summarize different categories dual demonstrate their benefits constructing new bonds selective manner. Finally, current challenges trends will also presented.

Language: Английский

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Cooperative Catalyst‐Enabled Regio‐ and Stereodivergent Synthesis of α‐Quaternary α‐Amino Acids via Asymmetric Allylic Alkylation of Aldimine Esters with Racemic Allylic Alcohols

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(46)

Published: Sept. 26, 2022

We describe cooperative bimetallic catalysis that enables regio-/stereodivergent asymmetric α-allylations of aldimine esters. By employing Et3 B as the key activator, racemic allylic alcohols can be directly ionized to form Pd or Ir-π-allyl species in presence achiral chiral Ir complexes, respectively. The less more substituted termini metal-π-allyl are amenable nucleophilic attack by Cu-azomethine ylide, formation which is simultaneously facilitated B, affording α-quaternary α-amino acids with high regioselectivity and excellent stereoselectivity. use readily available electrophilic precursors represents an improvement from environmental atom/step economy perspective. Computational mechanistic studies reveal crucial role additive origins stereo- regioselectivities analyzing steric effects, dispersion interactions, frontier orbital population.

Language: Английский

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Stereodivergent Construction of Csp³−Csp³Bonds Bearing Vicinal Stereocenters by Synergistic Palladium and Phase‐Transfer Catalysis

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(2)

Published: Nov. 16, 2022

Abstract Synergistic catalysis has emerged as one of the most powerful tools for stereodivergent formation Csp 3 −Csp bonds bearing vicinal stereocenters. Despite many successes that have been achieved in this field, coupling reactions involving stabilized nucleophiles remain challenging because competing single‐catalysis pathway. Herein, we report a synergistic palladium/phase‐transfer catalyst system enables diastereodivergent 1,3‐dienes with nucleophile oxindoles. Both syn and anti products, quaternary tertiary stereocenters, could be selectively produced good yields high enantio‐ diastereoselectivities. Non‐covalent activation via chiral ion pair biphasic is crucial success factor achieving diastereodivergence.

Language: Английский

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Enantioselective Synthesis of Spiroketals and Spiroaminals via Gold and Iridium Sequential Catalysis

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(26)

Published: April 21, 2022

Abstract The enantioselective cascade reaction between racemic 2‐(1‐hydroxyallyl)phenols and alkynols/alkynamides was realized by using a gold iridium sequential catalytic system. In this procedure, the in situ generated exocyclic vinyl ethers or enamides undergo asymmetric allylation/spiroketalization with π‐ally‐Ir amphiphilic species, which provides an efficient straightforward access to spiroketals spiroaminals excellent enantioselectivities. Moreover, 2‐(1‐hydroxyallyl)anilines were also suitable along kinetic resolution process, affording enantioenriched good yields. synthetic utility of method has been demonstrated synthesis analogue Paecilospirone.

Language: Английский

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Synergistic Palladium/Copper‐Catalyzed 1,4‐Difunctionalization of 1,3‐Dienes for Stereodivergent Construction of 1,5‐Nonadjacent Stereocenters

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(21)

Published: March 21, 2024

Abstract The construction of two distal stereocenters through a single catalytic process is great interest in organic synthesis. While there are some successful reports regarding stereodivergent preparation 1,3‐ or 1,4‐stereocenters, the more challenged 1,5‐nonadjacent have never been achieved fashion. Herein we describe synergistic palladium/copper catalysis for 1,4‐difunctionalization reactions 1,3‐dienes, providing access to quaternary stereocenters. Because each catalysts separately controlled one newly formed stereocenters, synthesis all four diastereomers products could readily be simply by choosing an appropriate combination chiral catalysts. Experimental and computational studies supported mechanism involving Heck/Tsuji–Trost cascade reaction, origins stereoselectivity were elucidated.

Language: Английский

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Iridium‐Catalyzed Asymmetric Allylic Substitution of Methyl Azaarenes

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(20)

Published: March 3, 2022

Abstract Herein, an Ir‐catalyzed asymmetric allylic substitution reaction of methyl azaarenes is described. Azaarenes such as (benzo)thiazole, oxazole, benzoimidazole, pyridine, and (iso)quinoline are all tolerated. The corresponding chiral azaarene derivatives obtained in good yields with high enantioselectivity (up to 96 % yield 99 ee). utilization the Knochel reagent TMPZnBr⋅LiBr warrants situ formation benzylic nucleophiles without additional activating reagents. 1 H NMR studies suggested a two‐fold function this reaction. synthetic utility method has been showcased by concise enantioselective synthesis allosteric protein kinase modulator.

Language: Английский

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Direct Asymmetric α‐C−H Addition of N‐unprotected Propargylic Amines to Trifluoromethyl Ketones by Carbonyl Catalysis

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(48)

Published: Oct. 10, 2022

Direct asymmetric functionalization of the inert α C-H bonds N-unprotected propargylic amines is a big challenge in organic chemistry, due to low acidity (pKa ≈42.6) and interruption nucleophilic NH2 group. By using chiral pyridoxal as carbonyl catalyst, we have successfully realized direct α-C-H addition trifluoromethyl ketones, producing broad range alkynyl β-aminoalcohols 54-84 % yields with excellent stereoselectivities (up 20 : 1 dr 99 ee). The are greatly activated by catalyst via formation an imine intermediate, resulting increase up 1022 times (from pKa 42.6 20.1), which become acidic enough be deprotonated under mild conditions for addition. This work presented impressive example enabled organocatalyst.

Language: Английский

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