Hydrogen Source Tuned Regiodivergent Asymmetric Hydroalkylations of 2‐Substituted 1,3‐Dienes with Aldehydes by Cobalt‐Catalysis

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(23)

Published: April 3, 2024

Abstract Catalytic methods allowing for the reliable prediction and control of diverse regioselectivity along with enantioselectivity to access different regio‐ enantiomers by switching least reaction parameters are one most attractive ways in organic synthesis, which provide enantioenriched architectures from identical starting materials. Herein, a Co‐catalyzed regiodivergent enantioselective reductive hydroalkylation 1,3‐dienes aldehydes has been achieved, furnishing homoallylic alcohol good levels enantioselectivity. The features switch tuned selection proton source. use an acid as source provided asymmetric 1,2‐hydroalkylation products under conditions, yet 4,3‐hydroalkylation were obtained silane hydride This catalytic protocol allows alcohols two continuous saturated carbon centers regio‐, diastereo‐,

Language: Английский

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Palladium‐Catalyzed Enantioselective Hydrofunctionalization of Alkenes: Recent Advances

European Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 26(43)

Published: Sept. 8, 2023

Abstract Palladium‐catalyzed asymmetric hydrofunctionalization of alkenes is one the most powerful and straightforward methods to forge a new C−H bond C−X (X=C, N, O, F, Si etc) bond, which provides an efficient way obtain valuable enantioenriched molecules from cheap readily available feedstocks. Catalytic simple challenging but still highly sought after. This review will mainly focus on recent advances in Palladium catalyzed over past decade, including hydroamination, hydrooxygenation, hydrofluorination, hydrosilylation, hydroarylation, hydroalkenylation hydrocarbonylation.

Language: Английский

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Chemodivergent Tandem Hydroalkylation and Hydroalkenoxylation of Conjugated Enynes

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(13), P. 9742 - 9751

Published: June 14, 2024

Due to the instability and weak O-nucleophilicity of enol, carbonyl compounds prefer function as C-nucleophiles instead O-nucleophiles in extensively studied transition metal-catalyzed hydrofunctionalizations unsaturated bonds. The corresponding hydroalkenoxylation reaction has thus long been unexplored. Here, we describe a chemodivergent protocol for challenging reactions. Dictated by Pd catalyst bearing different ligands, both 5-exo-trig 6-endo-trig processes are demonstrated be feasible between 1,3-enynes ketoesters, polysubstituted hydrofurans hydropyrans achieved good yields excellent chemoselectivities. In addition, enantioselective is also explored under an Rh moderate efficiency but with high stereoselectivities. Mechanistic studies corroborate designed tandem hydroalkylation uncover that ligand-to-ligand hydrogen transfer process might involved turnover-limiting step hydroalkenoxylation.

Language: Английский

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Asymmetric formal sp2-hydrocarbonations of dienes and alkynes via palladium hydride catalysis

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Oct. 9, 2023

Abstract Transition metal-catalyzed asymmetric hydrofunctionalizations of unsaturated bonds via π-ƞ 3 substitution have emerged as a reliable method to construct stereogenic centers, and mainly rely on the use heteroatom-based or carbon nucleophiles bearing acidic C-H bonds. In comparison, sp 2 are generally not under consideration because enormous challenges in cleaving corresponding inert Here, we report protocol achieve formal hydrocarbonations, including hydroalkenylation, hydroallenylation hydroketenimination both 1,3-dienes alkynes hydroalkylation Wittig reaction cascade. A series unachievable motifs hydrofunctionalizations, such di-, tri- tetra-substituted alkenes, allenes, tri-substituted ketenimines allyl skeletons all facilely constructed high regio-, diastereo- enantioselectivities with this cascade design. Stereodivergent synthesis four stereoisomers 1,4-diene stereocenter Z/E-controllable olefin unit highlights power present protocol. An interesting mechanistic feature is revealed that alkyne actually undergoes hydrocarbonation formation conjugated diene intermediate, different from conventional viewpoint hydrofunctionalization only involves allene species.

Language: Английский

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Modular Construction of Chiral Aminopiperidine via Palladium-Catalyzed Hydroamination of 1,2-Dihydropyridine

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 12, 2025

In this study, we describe a generally straightforward methodology for the catalytic synthesis of chiral aminopiperidine from pyridine and azoles. The key step was palladium-catalyzed regioselective N–H insertion into double bond 1,2-dihydropyridine. This hydroamination exhibits wide substrate scope functional group compatibility. Mechanistic study revealed that C═C followed cis addition. utility protocol demonstrated by diverse functionalization enamine bond.

Language: Английский

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Transition Metal-Catalyzed Asymmetric Migratory Allylic C—H Functionalization of Remote Dienes

Chinese Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: 45(2), P. 592 - 592

Published: Jan. 1, 2025

Language: Английский

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Tandem catalytic allylic C–H amination and asymmetric [2,3]-rearrangement via bimetallic relay catalysis

Chemical Science, Journal Year: 2024, Volume and Issue: 15(33), P. 13299 - 13305

Published: Jan. 1, 2024

An asymmetric tandem allylic C–H amination and [2,3]-sigmatropic rearrangement has been developed by making use of bimetallic relay catalysis with an achiral Pd(0) catalyst a chiral N,N ′-dioxide-Mg( ii ) complex.

Language: Английский

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Palladium(0) and Brønsted Acid Co‐catalyzed Enantioselective Hydro‐Cyclization of 2,4‐Dienyl Hydrazones and Oximes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(44)

Published: Aug. 6, 2024

Abstract The transition metal‐catalyzed asymmetric hydro‐functionalization of 1,3‐dienes has been well explored, but most reactions focus on electron‐neutral substrates in an intermolecular manner. Here we first demonstrate that readily available 2,4‐dienyl hydrazones and oximes can be efficiently utilized the hydro‐cyclization reaction under co‐catalysis a Brønsted acid chiral palladium complex, furnishing multifunctional dihydropyrazones dihydroisoxazoles, respectively. Diverse substitution patterns for both types electron‐deficient diene compounds are tolerated, corresponding heterocycles were generally constructed with moderate to excellent enantioselectivity, which elaborated access products higher molecular complexity diversity. Control experiments density functional theory calculations support α‐regioselective protonation dienyl by concurrent π‐Lewis base activation Pd 0 complex is energetically favoured formation active π‐allylpalladium intermediates, outer‐sphere allylic amination or etherification mode adopted deliver observed cyclized enantioselectively.

Language: Английский

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Palladium-Catalyzed Asymmetric O-1,5-Addition with Oximes via Hydroximation of Unsaturated Esters

Organic Letters, Journal Year: 2023, Volume and Issue: 26(1), P. 89 - 93

Published: Dec. 21, 2023

Different from electronically matched 1,4- and 1,6-additions, herein, we disclose an mismatched 1,5-conjugate addition process with oximes as the nucleophiles. By this design, oxime moieties are readily introduced to γ-position of electron-deficient substrates in good yields, excellent regioselectivities, high enantioselectivities. The corresponding allyl also conveniently transformed into a series valuable enantioenriched skeletons.

Language: Английский

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Stereoselective Synthesis of Polysubstituted Dihydropyrroles via 1,5‐Addition and N‐1,4‐Addition Cascade

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(38)

Published: May 3, 2024

An unprecedented 1,5-addition/N-1,4-addition cascade reaction is established via palladium hydride catalysis. A variety of polysubstituted dihydropyrrole skeletons are constructed in high yield and with exclusively >20 : 1 diastereoselectivity. enantioselective protocol this design also developed to provide a novel access enantioenriched dihydropyrroles.

Language: Английский

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