Versatile Cobalt-Catalyzed Enantioselective Entry to Boryl-Functionalized All-Carbon Quaternary Stereogenic Centers

Journal of the American Chemical Society, Год журнала: 2018, Номер 140(34), С. 10687 - 10690

Опубликована: Авг. 16, 2018

We report an asymmetric synthesis of chiral boryl-functionalized γ-lactams containing all-carbon quaternary stereocenters via a Co-catalyzed enantioselective hydroboration/cyclization amide-tethered 1,6-enynes. These enantio-enriched γ-lactam products can be readily converted to variety cyclic and acyclic other γ-lactams, pyrrolidin-2,3-diones, β-amino acid N-carboxyanhydrides, carboxylic amides.

Язык: Английский

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Photoredox‐Coupled F‐Nucleophilic Addition: Allylation of gem‐Difluoroalkenes

Angewandte Chemie International Edition, Год журнала: 2019, Номер 58(12), С. 3918 - 3922

Опубликована: Янв. 29, 2019

A novel strategy for the expedient construction of CF3 -embeded tertiary/quarternary carbon centers was developed by taking advantage photoredox catalysis. Thanks to a key step single-electron oxidation, electron-rich gem-difluoroalkenes, which otherwise are essentially reluctant towards F-nucleoplilic addition, now readily participate in this fluoroallylation reaction. Furthermore, provides an elegant example generation, as well functionalization, α-CF3 -substituted benzylic radical intermediates using cheap and available starting materials.

Язык: Английский

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Hydrogen‐Transfer‐Mediated α‐Functionalization of 1,8‐Naphthyridines by a Strategy Overcoming the Over‐Hydrogenation Barrier

Angewandte Chemie International Edition, Год журнала: 2017, Номер 56(45), С. 14232 - 14236

Опубликована: Сен. 19, 2017

A general catalytic hydrogen transfer-mediated α-functionalization of 1,8-naphthyridines is reported for the first time that benefits from a activation mode non-activated pyridyl cores. The α-site selectively couples with C8-site various tetrahydroquinolines (THQs) to afford novel α-functionalized tetrahydro 1,8-naphthyridines, class synthetically useful building blocks and potential candidates discovery therapeutic bio-active products. utilization THQs as inactive donors (HDs) appears be key strategy overcome over-hydrogenation barrier address chemoselectivity issue. developed chemistry features operational simplicity, readily available catalyst good functional group tolerance, offers significant basis further development new protocols directly transform or functionalize inert N-heterocycles.

Язык: Английский

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Nickel/N-Heterocyclic Carbene Complex-Catalyzed Enantioselective Redox-Neutral Coupling of Benzyl Alcohols and Alkynes to Allylic Alcohols

ACS Catalysis, Год журнала: 2018, Номер 9(1), С. 1 - 6

Опубликована: Ноя. 29, 2018

The nickel-catalyzed enantioselective redox-neutral coupling of alcohols and alkynes to access chiral allylic is reported. reaction proceeds via a hydrogen transfer process under ambient temperature, converting abundant feedstock with high stereoselectivities in one chemical step. Key the success this was development bulky N-heterocyclic carbene, (R,R,R,R)-SIPE, version SIPr, as ligand for nickel. Notably, we found that utilization P(OPh)3 secondary nickel crucial inhibit isomerization products.

Язык: Английский

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Engaging Aldehydes in CuH‐Catalyzed Reductive Coupling Reactions: Stereoselective Allylation with Unactivated 1,3‐Diene Pronucleophiles

Angewandte Chemie International Edition, Год журнала: 2019, Номер 58(47), С. 17074 - 17080

Опубликована: Сен. 25, 2019

Abstract Recently, CuH‐catalyzed reductive coupling processes involving carbonyl compounds and imines have become attractive alternatives to traditional methods for stereoselective addition because of their ability use readily accessible stable olefins as surrogates organometallic nucleophiles. However, the inability aldehydes, which usually reduce too rapidly in presence copper hydride complexes be viable substrates, has been a major limitation. Shown here is that by exploiting relative concentration effects through kinetic control, this intrinsic reactivity can inverted 1,3‐dienes with aldehydes achieved. Using method, both aromatic aliphatic transformed into synthetically valuable homoallylic alcohols high levels diastereo‐ enantioselectivities, many useful functional groups. Furthermore, using combination theoretical (DFT) experimental methods, important mechanistic features reaction related stereo‐ chemoselectivities were uncovered.

Язык: Английский

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Catalytic Asymmetric Conjugate Protosilylation and Protoborylation of 2-Trifluoromethyl Enynes for Synthesis of Functionalized Allenes

Organic Letters, Год журнала: 2020, Номер 22(4), С. 1360 - 1367

Опубликована: Фев. 4, 2020

The Cu-catalyzed 1,4-protosilylation and protoborylation of trifluoromethyl-substituted conjugated enynes were developed to access functionalized homoallenylsilanes homoallenylboronates. This protocol also provides a general method synthesize optically active homoallenylboronates in moderate excellent yields with high enantiomeric excess by using new designed chiral bisoxazoline ligands. Simultaneously, the transformations explored useful building blocks.

Язык: Английский

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Cobalt-Catalyzed Diastereo- and Enantioselective Reductive Allyl Additions to Aldehydes with Allylic Alcohol Derivatives via Allyl Radical Intermediates

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(32), С. 12755 - 12765

Опубликована: Авг. 5, 2021

Catalytic generation of ambiphilic π-allyl–metal complexes and their utility in enantioselective transformations constitutes a powerful approach for introduction allyl groups to molecule. Herein an unprecedented cobalt-catalyzed highly site-, diastereo-, protocol stereoselective formation nucleophilic allyl–Co(II) followed by addition aldehydes is presented. The reaction features diastereo- enantioconvergent conversion easily accessible allylic alcohol derivatives diversified enantioenriched homoallylic alcohols with remarkably broad scope that can be introduced. Mechanistic studies indicated radical intermediates were involved this process. These new discoveries establish strategy development through capture radicals chiral Co complexes, pushing forward the frontier catalysis.

Язык: Английский

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Allenes and Dienes as Chiral Allylmetal Pronucleophiles in Catalytic Enantioselective C=X Addition: Historical Perspective and State‐of‐The‐Art Survey

Chemistry - A European Journal, Год журнала: 2021, Номер 27(52), С. 13107 - 13116

Опубликована: Июнь 29, 2021

Abstract The use of allenes and 1,3‐dienes as chiral allylmetal pronucleophiles in intermolecular catalytic enantioselective reductive additions to aldehydes, ketones, imines, carbon dioxide other C=X electrophiles is exhaustively catalogued together with redox‐neutral hydrogen auto‐transfer processes. Coverage limited processes that result both C−H C−C bond formation. alkynes latent multicomponent allylations involving dienes not covered. As illustrated this review, the ability serve tractable non‐metallic has evoked many useful transformations have no counterpart traditional chemistry.

Язык: Английский

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Enantioselective Hydroalkoxylation of 1,3-Dienes via Ni-Catalysis

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(7), С. 3909 - 3914

Опубликована: Фев. 10, 2023

As an advance in hydrofunctionalization, we herein report that alcohols add to 1,3-dienes with high regio- and enantioselectivity. Using Ni-DuPhos, access enantioenriched allylic ethers. Through the choice of solvent-free conditions, control reversibility C–O bond formation. This work showcases a rare example methanol as reagent asymmetric synthesis.

Язык: Английский

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Research progress in electrochemical/photochemical utilization of methanol as a C1 source

Green Chemistry, Год журнала: 2023, Номер 25(21), С. 8313 - 8327

Опубликована: Янв. 1, 2023

This review highlights the recent advances in various electrochemical and photochemical reactions using methanol as a sustainable C1 source.

Язык: Английский

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