Palladium‐Catalyzed Alkyne Hydrocyanation toward Ligand‐Controlled Stereodivergent Synthesis of (E)‐ and (Z)‐Trisubstituted Acrylonitriles

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(26)

Опубликована: Апрель 27, 2023

We herein describe a palladium-catalyzed hydrocyanation of propiolamides for the stereodivergent synthesis trisubstituted acrylonitriles. This synthetic method tolerated various primary, secondary and tertiary propiolamides. The cautious selection suitable ligand is essential to success this process. Control experiments indicate intermediacy E-acrylonitriles, which lead Z-acrylonitriles via isomerization. density functional theory calculations suggests that bidentate L2 enables feasible cyclometallation/isomerization pathway E Z isomerization, while monodentate L1 inhibits leading divergent stereoselectivity. usefulness can be demonstrated by readily derivatization products give E- Z-trisubstituted alkenes. In addition, Z-acrylonitrile have also been successfully employed in cycloaddition reactions.

Язык: Английский

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Enantioselective Ni-Catalyzed 1,2-Borylalkynylation of Unactivated Alkenes

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(25), С. 17140 - 17149

Опубликована: Июнь 12, 2024

Enantioselective three-component difunctionalization of alkenes with boron reagents represents an attractive strategy for assembling three-dimensional chiral organoboron compounds. However, regio- and enantiocontrol comprise the pivot challenges in these transformations, which predominantly require use activated conjugated alkenes. Herein, by utilizing various carbonyl directing groups, including amides, sulfinamides, ketones, esters, we succeed realizing a nickel-catalyzed 1,2-borylalkynylation unactivated to enable simultaneous incorporation entity sp-fragment across double bond. The products contain boryl, alkynyl, functional groups orthogonal synthetic reactivities, offering three handles further derivatization access valuable intermediates. utility this ligand-enabled asymmetric protocol has been highlighted through late-stage decoration drug-relevant molecules.

Язык: Английский

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Recent advances on transition-metal-catalyzed asymmetric tandem reactions with organoboron reagents

Coordination Chemistry Reviews, Год журнала: 2019, Номер 392, С. 35 - 48

Опубликована: Май 9, 2019

Язык: Английский

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Hydroboration of Nitriles, Esters, and Carbonates Catalyzed by Simple Earth‐Abundant Metal Triflate Salts

Chemistry - An Asian Journal, Год журнала: 2021, Номер 16(8), С. 999 - 1006

Опубликована: Март 17, 2021

Abstract During the past decade earth‐abundant metals have become increasingly important in homogeneous catalysis. One of reactions which found applications is hydroboration unsaturated C−C and C−X bonds (X=O or N). Within these set transformations, challenging substrates such as nitriles, carbonates esters still remain difficult often relies on elaborate ligand designs highly reactive catalysts (e. g., metal alkyls/hydrides). Here we report an effective methodology for C≡N C=O that simple applicable to a wide substrates. The based using manganese(II) triflate salt that, combination with commercially available potassium tert ‐butoxide pinacolborane, catalyzes carbonates, at room temperature near quantitative yields less than three hours. Additional studies demonstrated other salts can facilitate this reaction well, further discussed report.

Язык: Английский

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Ruthenium‐Catalyzed Geminal Hydroborative Cyclization of Enynes

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(31)

Опубликована: Май 21, 2022

Disclosed here is the first geminal (gem-) hydroborative cyclization of enynes. Different from known cyclizations, this process adds hydrogen and boron to same position, leading a new reaction mode. With [Cp*RuCl]4 as catalyst, range gem-hydroborated bicyclic products bearing cyclopropane unit could be rapidly assembled simple enyne substrates. Control experiments density functional theory (DFT) calculations provided important insights into mechanism. Notably, two major competing pathways may operate with substrate-dependence. 1,6-Enynes favor initial oxidative cyclometalation form ruthenacyclopentene intermediate prior engaging hydroborane, while other enynes (e.g., 1,7-enynes) that lack strong propensity toward prefer alkyne gem-(H,B)-addition an α-boryl ruthenium carbene followed by intramolecular olefin cyclopropanation. This also represents ruthenium-catalyzed cyclization.

Язык: Английский

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