Light opens a new window for N-heterocyclic carbene catalysis

Chemical Science, Journal Year: 2020, Volume and Issue: 11(39), P. 10605 - 10613

Published: Jan. 1, 2020

N-Heterocyclic carbenes (NHCs) are efficient Lewis basic catalysts for the umpolung of various polarized unsaturated compounds usually including aldehydes, imines, acyl chlorides and activated esters. NHC catalysis involving electron pair transfer steps has been extensively studied; however, through single-electron (SET) processes, despite having potential to achieve chemical transformations inert bonds using green reagents, long a challenging task in organic synthesis. In parallel, visible-light-induced photocatalysis photoexcitation have established as powerful tools facilitate sustainable synthesis, they enable generation reactive radical intermediates under extremely mild conditions. Recently, number elegant visible-light-induced, NHC-catalyzed were developed accessing valuable compounds. As result, this minireview will highlight recent advances field.

Language: Английский

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Direct Enantioselective C(sp³)–H Acylation for the Synthesis of α-Amino Ketones

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(45), P. 19058 - 19064

Published: Oct. 30, 2020

A direct enantioselective acylation of α-amino C(sp3)-H bonds with carboxylic acids has been achieved via the merger transition metal and photoredox catalysis. This straightforward protocol enables cross-coupling a wide range acids, one class feedstock chemicals, readily available N-alkyl benzamides to produce highly valuable ketones in high enantioselectivities under mild conditions. The synthetic utility this method is further demonstrated by gram scale synthesis application late-stage functionalization. provides an unprecedented solution address challenging stereocontrol metallaphotoredox catalysis Mechanistic studies suggest α-C(sp3)-H bond benzamide coupling partner cleavage photocatalytically generated bromine radicals form alkyl radicals, which subsequently engages nickel-catalyzed asymmetric acylation.

Language: Английский

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Enantio‐ and Diastereodivergent Synthesis of Spirocycles through Dual‐Metal‐Catalyzed [3+2] Annulation of 2‐Vinyloxiranes with Nucleophilic Dipoles

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(47), P. 24941 - 24949

Published: Sept. 17, 2021

The development of efficient and straightforward methods for obtaining all optically active isomers structurally rigid spirocycles from readily available starting materials is great value in drug discovery chiral ligand development. However, the stereodivergent synthesis bearing multiple stereocenters remains an unsolved challenge owing to steric hindrance ring strain. Herein, we report enantio- diastereodivergent through dual-metal-catalyzed [3+2] annulation oxy π-allyl metallic dipoles with less commonly employed nucleophilic (imino esters). A series spiro compounds a pyrroline olefin were easily synthesized manner (up 19:1 dr, >99 % ee), which showed promise as new type N-olefin ligand. Preliminary mechanistic studies also carried out understand process this bimetallic catalysis.

Language: Английский

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High-order dipolar annulations with metal-containing reactive dipoles

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(10), P. 4146 - 4174

Published: Jan. 1, 2022

The advances on metal-catalysed high-order dipolar annulations were comprehensively summarized in this review. To further exploit the potential of unique annulation strategy, a research outlook was also proposed.

Language: Английский

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Advances in heterocycle synthesis through photochemical carbene transfer reactions

Chemical Communications, Journal Year: 2024, Volume and Issue: 60(16), P. 2125 - 2136

Published: Jan. 1, 2024

In this feature article, we focus on the photochemical strategy for construction of heterocyclic skeletons, specifically highlighting methods that employ visible light-promoted carbene transfer reactions.

Language: Английский

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Regiodivergent Synthesis of Spirocyclic Compounds through Pd‐Catalyzed Regio‐ and Enantioselective [3+2] Spiroannulation

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(11), P. 5806 - 5810

Published: Jan. 21, 2021

Abstract A novel Pd 0 ‐catalyzed highly regio‐ and enantioselective [3+2] spiroannulation reaction has been developed for rapid assembly of a new class [5,5] spirocyclic carbo‐ heterocycles. Notably, the regioselectivity could be dominated by fine‐tuning Pd‐π‐allyl intermediate. An array coupling partners well‐tolerated with excellent regio‐, enantioselectivities. Moreover, potential application this was exemplified several further transformations.

Language: Английский

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Evolution in heterodonor P-N, P-S and P-O chiral ligands for preparing efficient catalysts for asymmetric catalysis. From design to applications

Coordination Chemistry Reviews, Journal Year: 2021, Volume and Issue: 446, P. 214120 - 214120

Published: July 19, 2021

The success of phosphine-oxazoline ligands (PHOX) inspired the progress in P-oxazoline ligand families by modifying either backbone, electronic and/or steric properties phosphine group or exchanging to a phosphinite phosphite group. In this respect, structures chiral have become more diverse and new very efficient emerged, which improved catalytic performance some asymmetric transformations, with an increased versatility, both range reactions substrates/reagents. addition, most are synthesized from easily accessible amino alcohols, maintaining short synthetic route developed for PHOX ligands. New been replacing oxazoline functionality several other N-donor groups, e.g. imidazole, thiazole, oxazole, pyridine, etc., O- S-groups. This review offers critical overview utility these successful bidentate heterodonor P-N, P-O P-S applied metal-mediated processes. We illustrate how, through proper design, can be excellent source ligands, superior many than best C2-symmetric N,N P,P-ligands reported so far.

Language: Английский

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Recent advances in Pd-catalyzed asymmetric cyclization reactions

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 53(2), P. 883 - 971

Published: Dec. 18, 2023

This review aims to collect advancements in enantioselective palladium-catalyzed cyclization reactions over the past eleven years, and it is organized into thirteen sections depending on different types of transformations involved.

Language: Английский

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Synthesis of Chiral Endocyclic Allenes and Alkynes via Pd-Catalyzed Asymmetric Higher-Order Dipolar Cycloaddition

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 18, 2024

A Pd-catalyzed asymmetric higher-order dipolar cycloaddition between allenyl carbonates and azadienes is achieved by exploiting novel alkylidene-π-allyl-Pd dipoles. This research provides a modular platform for the synthesis of challenging chiral endocyclic allenes bearing medium-sized heterocyclic motif centrally stereocenter in good yields with high enantio- diastereoselectivities (29 examples, up to 97% yield, 97:3 er >19:1 dr). Experimental computational studies elucidate possible reaction mechanism observed stereochemical results. Based on mechanistic understanding, new π-propargyl-Pd dipole was designed further extend success higher order strategy 10-membered alkynes from propargyl (13 98% yield 94.5:5.5 er).

Language: Английский

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Catalytic asymmetric photocycloaddition reactions mediated by enantioselective radical approaches

Chemical Society Reviews, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

The use of olefins in the construction cyclic compounds represents a powerful strategy for advancing pharmaceutical industry.

Language: Английский

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