Merging Organocatalysis with 1,2-Boronate Rearrangement: A Lewis Base-Catalyzed Asymmetric Multicomponent Reaction

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(40), P. 27305 - 27311

Published: Sept. 24, 2024

Catalytic asymmetric multicomponent 1,2-boronate rearrangements provide a practical approach for synthesizing highly valuable enantioenriched boronic esters. When applied to alkenyl or heteroaryl boronates, these reactions have relied mainly on transition-metal catalysis. Herein, we present an organocatalytic, Lewis base-catalyzed rearrangement, involving indoles, esters, and Morita-Baylis-Hillman carbonates, leading enantioenriched, substituted indole indoline derivatives. Using cinchona alkaloid-based catalysts, high selectivity has been achieved, enabling expansion of the chemical space around pharmaceutically relevant

Language: Английский

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Lewis-Base-Catalyzed N-Allylation of Silyl Carbamate Latent Pronucleophiles with Allylic Fluorides

Organic Letters, Journal Year: 2023, Volume and Issue: 25(51), P. 9097 - 9102

Published: Dec. 15, 2023

Silyl carbamates, latent pronucleophile surrogates of undergo allylation using allylic fluorides in the presence common Lewis base catalysts. The reactions are rendered enantioselective chiral catalysts and produce suitably protected derivatives enantioenriched β-amino acids. design featuring both a silyl group an electron-deficient carbamate is instrumental lowering nucleophilicity nitrogen enabling cinchona alkaloid-based

Language: Английский

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Enantioselective Lewis Base Catalysed Allylation of Picoline- and Quinaldine-based Latent Pronucleophiles

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(33), P. 6684 - 6689

Published: Jan. 1, 2024

The concept of latent pronucleophiles enables selective allylation picolines and quinaldines with allylic fluorides in the presence Lewis base catalysts. products are isolated as single regioisomers good yields enantioselectivity.

Language: Английский

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Organocatalytic Asymmetric Allylic Benzylborylation via Fluoride-Assisted Catalytic Generation of α-Boryl Carbanionic Intermediates

Organic Letters, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 20, 2024

Herein we describe the organocatalytic asymmetric allylic benzylborylation of allyl fluorides with α-silyl benzylboronic esters. The catalytic protocol leverages singular features fluoride as an unconventional leaving group, enabling generation reactive α-boryl carbanion species through desilylative activation. It allows construction a wide set homoallylic benzylated organoboronates bearing two contiguous stereocenters. chiral boronate installed in products serves synthetic lynchpin to construct complex chemical architectures stereospecific manner.

Language: Английский

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Defluorinative Asymmetric Allylic Alkylations

Synlett, Journal Year: 2023, Volume and Issue: 35(14), P. 1613 - 1620

Published: Nov. 15, 2023

Abstract The introduction of allyl fluorides as alternative electrophiles in asymmetric allylic alkylation reactions has recently attracted significant interest. Despite the intrinsic thermodynamically demanding C–F bond-cleavage event, fluorophilic nature silicon atom is key assisting activation and cleavage bond. Thus, use silylated compounds unconventional nucleophiles, together with Lewis basicity fluorine when acting a leaving group, enables development innovative chemical transformations within mild selective catalytic schemes. This Synpacts article summarizes diverse defluorinative alkylations reported to date under both chiral base transition-metal catalysis.

Language: Английский

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Regioconvergent Nucleophilic Substitutions with Morita–Baylis–Hillman Fluorides

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(15), P. 10998 - 11002

Published: July 17, 2024

Lithium iodide enables regioconvergent C–F bond functionalization of isomeric Morita–Baylis–Hillman fluorides with carbon, sulfur, and nitrogen nucleophiles. The defluorinative carbon–carbon carbon–heteroatom formations give multifunctional compounds in excellent yields good to high diastereoselectivities at room temperature. possibility catalytic enantioselective allylation is also discussed.

Language: Английский

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Stereospecific 3‐Aza‐Cope Rearrangement Interrupted Asymmetric Allylic Substitution‐Isomerization

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 17, 2024

Transition-metal catalyzed asymmetric allylic substitution with alkyl and heteroaryl carbon nucleophiles has been well-established. However, the arylation of acyclic internal alkenes aryl remains challenging underdeveloped. Herein we report a stereospecific 3-aza-Cope rearrangement interrupted substitution-isomerization (Int-AASI) that enables arylation. By means this stepwise strategy, both enantioenriched products axially chiral could be readily obtained in high enantioselectivities. Experimental studies support mechanism involving cascade amination, alkene isomerization. Density functional theory detailed reasons achieving chemoselectivity, regioselectivity, stereoselectivity stereospecificity, respectively.

Language: Английский

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Stereospecific 3‐Aza‐Cope Rearrangement Interrupted Asymmetric Allylic Substitution‐Isomerization

Angewandte Chemie, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 17, 2024

Abstract Transition‐metal catalyzed asymmetric allylic substitution with alkyl and heteroaryl carbon nucleophiles has been well‐established. However, the arylation of acyclic internal alkenes aryl remains challenging underdeveloped. Herein we report a stereospecific 3‐aza‐Cope rearrangement interrupted substitution‐isomerization ( Int‐AASI ) that enables arylation. By means this stepwise strategy, both enantioenriched products axially chiral could be readily obtained in high enantioselectivities. Experimental studies support mechanism involving cascade amination, alkene isomerization. Density functional theory detailed reasons achieving chemoselectivity, regioselectivity, stereoselectivity stereospecificity, respectively.

Language: Английский

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Silyl Ethers as Latent Pronucleophiles in Enantioselective Lewis Base Catalyzed Synthesis of Allylic Ethers from Allylic Fluorides

Synlett, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 22, 2024

Abstract Allylic ethers are a common occurrence in natural products, and often used as intermediates target-oriented synthesis. Their synthesis relies on the use of transition-metal catalysts. Here, we report an organocatalytic method for allylation O-centered nucleophiles, Lewis base catalyzed silyl with allylic fluorides. The concept latent pronucleophiles catalysis to overcome limitations substrate scope, even permitting sterically congested O-pronucleophiles. When chiral catalysts used, allyl produced enantioenriched form through kinetic resolution fluorides, where stereoselectivity is determined by catalyst.

Language: Английский

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