Recent Advances in Enantioselective Pd-Catalyzed Allylic Substitution: From Design to Applications

Chemical Reviews, Journal Year: 2021, Volume and Issue: 121(8), P. 4373 - 4505

Published: March 19, 2021

This Review compiles the evolution, mechanistic understanding, and more recent advances in enantioselective Pd-catalyzed allylic substitution decarboxylative oxidative substitutions. For each reaction, catalytic data, as well examples of their application to synthesis complex molecules, are collected. Sections which we discuss key aspects for high selectivity a comparison with other metals (with advantages disadvantages) also included. asymmetric substitution, data grouped according type nucleophile employed. Because prominent position use stabilized carbon nucleophiles heteronucleophiles, many chiral ligands have been developed. To better compare results, they presented by ligand types. reactions mainly promoted PHOX or Trost ligands, justifies organizing this section chronological order. results used.

Language: Английский

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Synergistic Dual Catalysis in Stereodivergent Synthesis

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(6), P. 3812 - 3844

Published: Feb. 23, 2024

Chiral skeletons with multiple stereogenic centers widely reside in nature and drugs, their relative absolute configuration often determine physiological or pharmacological properties. Stereodivergent synthesis of chiral molecules is not only great significance, but also highly challenging since the formation one diastereomers inherently preferred most asymmetric reactions. dual catalysis, introduced 2013 by Carreira group, perfectly catered to all requirements for full stereoselectivity control given reactions two catalysts are utilized a synergistic way act independently, has now been arguably efficient strategy realize stereodivergent synthesis. This comprehensive review presents an overview development enabled catalysis past ten years, providing readers fundamental attributes as well ability, scope, mechanism, limitations this strategy.

Language: Английский

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Palladium-Catalyzed Asymmetric Allylic Alkylation Strategies for the Synthesis of Acyclic Tetrasubstituted Stereocenters

Synthesis, Journal Year: 2018, Volume and Issue: 51(01), P. 1 - 30

Published: Dec. 5, 2018

Over the past 20 years, asymmetric synthesis of acyclic tetrasubstituted stereocenters by Pd-catalyzed allylic alkylation (Pd-AAA) strategies has seen considerable growth. Despite inherent difficulty in accessing stereocenters, creative approaches toward this problem have resulted high stereoinduction on both electrophilic and nucleophilic reaction partners. Much chemistry paved way for unique solutions Mo-, Ir-, Rh-AAA, with many complimentary methods arising due to regiochemical outcomes AAA outside Pd catalysis. 1 Introduction 2 Stereocontrol Prochiral Electrophiles 3 Nucleophiles 4 Temporary Cyclic Pronucleophiles 5 Allylic Alkylation Other Metals 6 Conclusions Outlook

Language: Английский

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Catalytic Enantioselective Alkylation of Prochiral Enolates

Chemical Reviews, Journal Year: 2021, Volume and Issue: 121(15), P. 9196 - 9242

Published: July 26, 2021

The asymmetric alkylation of enolates is a particularly versatile method for the construction α-stereogenic carbonyl motifs, which are ubiquitous in synthetic chemistry. Over past several decades, focus has shifted to development new catalytic methods that depart from classical stoichiometric stereoinduction strategies (e.g., chiral auxiliaries, alkali metal amide bases, electrophiles, etc.). In this way, enantioselective prochiral greatly improves step- and redox-economy process, addition enhancing scope selectivity these reactions. review, we summarize origin advancement enolate methods, with directed emphasis on union nucleophiles carbon-centered electrophiles derivatives. Hence, transformative developments each distinct class nucleophile ketone enolates, ester etc.) presented modular format highlight state-of-the-art current limitations area.

Language: Английский

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A Type of Structurally Adaptable Aromatic Spiroketal Based Chiral Diphosphine Ligands in Asymmetric Catalysis

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(3), P. 668 - 684

Published: Jan. 14, 2021

ConspectusWhile spectacular successes have been achieved in homogeneous catalysis with the use of achiral diphosphine ligands featuring a wide natural bite angle, such as XantPhos, chiral diphosphines that can induce large P–M–P angle their transition metal complexes are conspicuously less explored asymmetric catalysis, probably due to challenges identification and efficient construction suitable backbone. In past decade, highly synthesis aromatic spiroketals corresponding (SKPs) has developed this group.Based on one-pot catalytic tandem double hydrogenation–spiroketalization ring-closure reaction sequence, these SKP an extraordinarily long P···P distance flexible backbone readily prepared scale. Remarkably versatile coordination modes found some catalysis-relevant metals, for example, Pd, Cu, Au, Rh. Whereas enforces unusually [Pd(SKP)Cl2] [Cu(SKP)Cl] (160.1° 132.8°, respectively), it also allows bimetallic Au–Au interaction (3.254 Å) complex [Au2(SKP)Cl2] or square-planar geometry [Rh(SKP)(cod)]SbF6 complex. Such adaptable nature profound consequences demonstrated by unique performance several types reactions. One most exciting examples is SKP/Pd-catalyzed allylic amination Morita–Baylis–Hillman (MBH) adducts, which SKP/Pd excellent control regio- enantioselectivities exhibited exceptionally high efficiency (with TON up 4750) catalysis. diversity successful applications Cu-, Au-, Rh-catalyzed reactions, further attesting utilities Overall, class accessible spiroketal skeleton structures variety provided outstanding difficult transformations. The works delineated herein would be expected stimulate research efforts application type ligand provide useful clues design new angles catalyzed

Language: Английский

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Tandem Allylation/1,2-Boronate Rearrangement for the Asymmetric Synthesis of Indolines with Adjacent Quaternary Stereocenters

Journal of the American Chemical Society, Journal Year: 2018, Volume and Issue: 140(41), P. 13242 - 13252

Published: Sept. 21, 2018

A three-component coupling using lithiated indoles, boronate esters and allylic acetates generates chiral indolines with adjacent quaternary stereocenters. Successful stereocontrol required the use of phosphoramidite ligands not previously described for organopalladium chemistry. Mechanistic studies indicate a monodentate PdL intermediate, stepwise allylation-aryl/alkyl migration. protodeborylation strategy was used to install C–H bond in place C–B bond. photoredox replace C–C highly diastereoselective manner. In specific case methyl-vinyl ketone, novel radical-mediated annulation provides polycyclic products high enantio- diastereoselectivity.

Language: Английский

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Primary, Secondary, and Tertiary γ-C(sp³)–H Vinylation of Amides via Organic Photoredox-Catalyzed Hydrogen Atom Transfer

Organic Letters, Journal Year: 2018, Volume and Issue: 20(19), P. 6255 - 6259

Published: Sept. 24, 2018

An efficient strategy for primary, secondary and tertiary aliphatic γ-C(sp3)–H vinylation of amides with alkenylboronic acids is reported. These reactions are catalyzed by visible-light organic photoredox agents. Regioselective controlled a 1,5-hydrogen atom transfer an amidyl radical generated in situ.

Language: Английский

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Merging enzymes with chemocatalysis for amide bond synthesis

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Jan. 19, 2022

Abstract Amides are one of the most fundamental chemical bonds in nature. In addition to proteins and other metabolites, many valuable synthetic products comprise amide bonds. Despite this, there is a need for more sustainable synthesis. Herein, we report an integrated next generation multi-catalytic system, merging nitrile hydratase enzymes with Cu-catalysed N-arylation reaction single vessel, construction ubiquitous This synergistic one-pot combination chemo- biocatalysis provides bond disconnection precursors, that orthogonal those classical synthesis, obviating protecting groups delivering amides manner unachievable using existing catalytic regimes. Our approach also affords broad scope, very high (molar) substrate loading, has excellent functional group tolerance, telescoping routes natural product derivatives, drug molecules, challenging chiral under environmentally friendly conditions at scale.

Language: Английский

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Photosensitized O ₂ enables intermolecular alkene cyclopropanation by active methylene compounds

Science, Journal Year: 2023, Volume and Issue: 381(6657), P. 545 - 553

Published: Aug. 3, 2023

Cyclopropanes are key features in many preclinical, clinical, and commercial drugs, as well natural products. The most prolific technique for their synthesis is the metal-catalyzed reaction of an alkene with a diazoalkane, highly energetic reagent requiring stringent safety precautions. Discovery alternative innocuous reagents remains ongoing challenge. Herein, we report simple photoredox-catalyzed intermolecular cyclopropanation unactivated alkenes active methylene compounds. proceeds neutral solvent under air or dioxygen (O 2 ) photoredox catalyst excited by blue light-emitting diode light iodine co-catalyst that either added molecular generated situ from alkyl iodides. Mechanistic investigations indicate photosensitized O plays vital role generation carbon-centered radicals both addition compounds to ring closure.

Language: Английский

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Expanding Reaction Profile of Allyl Carboxylates via 1,2-Radical Migration (RaM): Visible-Light-Induced Phosphine-Catalyzed 1,3-Carbobromination of Allyl Carboxylates

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(15), P. 8275 - 8284

Published: April 5, 2023

Allyl carboxylates are useful synthetic intermediates in a variety of organic transformations, including catalytic nucleophilic/electrophilic allylic substitution reactions and 1,2-difunctionalization reactions. However, the 1,3-difunctionalization allyl remains elusive. Herein, we report first photoinduced, phosphine-catalyzed 1,3-carbobromination carboxylates, affording range valuable substituted isopropyl (sIPC). The transformation has broad functional group tolerance, is amenable to late-stage modification complex molecules gram-scale synthesis, expands reaction profiles phosphine catalysis. Preliminary experimental computational studies suggest non-chain-radical mechanism involving formation an electron donor-acceptor complex, 1,2-radical migration (RaM), Br-atom transfer processes. We anticipate that 1,2-RaM reactivity radical will both serve as platform for development new transformations synthesis.

Language: Английский

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