Iridium-Catalyzed Asymmetric Allylic Substitution Reactions

Chemical Reviews, Год журнала: 2018, Номер 119(3), С. 1855 - 1969

Опубликована: Дек. 24, 2018

In this review, we summarize the origin and advancements of iridium-catalyzed asymmetric allylic substitution reactions during past two decades. Since first report in 1997, Ir-catalyzed have attracted intense attention due to their exceptionally high regio- enantioselectivities. been significantly developed recent years many respects, including ligand development, mechanistic understanding, substrate scope, application synthesis complex functional molecules. an explicit outline ligands, mechanism, scope nucleophiles, applications is presented.

Язык: Английский

---

Synergistic Dual Transition Metal Catalysis

Chemical Reviews, Год журнала: 2020, Номер 120(24), С. 13382 - 13433

Опубликована: Ноя. 29, 2020

Synergistic catalysis, a type of plural catalysis which utilizes at least two different catalysts to enable reaction between separately activated substrates, has unlocked plethora previously unattainable transformations and novel chemical reactivity. Despite the appreciable utility synergistic specific examples involving transition metals have been limited, as ensuring judicious choice parameters prevent deactivation catalysts, undesirable monocatalytic event(s) leading side products, or premature termination other potentially troublesome outcomes present formidable challenge. Excluding those driven by photocatalytic mechanisms, this review will highlight reported reactions that make use simultaneous catalytic cycles metal catalysts.

Язык: Английский

---

Stereodivergent Coupling of 1,3-Dienes with Aldimine Esters Enabled by Synergistic Pd and Cu Catalysis

Journal of the American Chemical Society, Год журнала: 2019, Номер 141(37), С. 14554 - 14559

Опубликована: Сен. 3, 2019

Herein we describe the use of synergistic Pd and Cu catalysis for stereodivergent coupling reactions between 1,3-dienes aldimine esters. By using different enantiomers two metal catalysts, all four stereoisomers products, which have vicinal stereocenters, could be accessed with high diastereo- enantioselectivity. This atom-economical cross-coupling reaction has a wide substrate scope good functional group tolerance. Our work highlights power asymmetric involving Pd-hydride catalysts.

Язык: Английский

---

Challenges and Opportunities in Multicatalysis

ACS Catalysis, Год журнала: 2021, Номер 11(7), С. 3891 - 3915

Опубликована: Март 15, 2021

Multicatalysis is an emerging field targeting the development of efficient catalytic transformations to quickly convert relatively simple starting materials into more complex value-added products. Within multicatalytic processes either multiple catalysts execute single reactions or precise sequences occur in a "one-pot" fashion. Attractively, protocols not only enable that are inaccessible through classic approaches but also able significantly reduce time, waste, and cost synthetic processes, making organic synthesis resources efficient. In this Perspective article, we review different strategies multicatalysis bring distinct challenges opportunities. We divide overarching three main categories: cooperative, domino, relay catalysis. Each category described along with representative examples highlight its features. Special emphasis dedicated catalysis, which further discussed subcategories. Lastly, provide analysis systems incorporate higher levels complexity underscore potential systems.

Язык: Английский

---

Stereodivergent Construction of Tertiary Fluorides in Vicinal Stereogenic Pairs by Allylic Substitution with Iridium and Copper Catalysts

Journal of the American Chemical Society, Год журнала: 2019, Номер 141(33), С. 13066 - 13073

Опубликована: Июль 25, 2019

Although much effort has been spent on the enantioselective synthesis of tertiary alkyl fluorides, compounds containing such a stereogenic center within an array stereocenters, particularly two vicinal ones, remains synthetic challenge, and no method to control configuration each independently reported. We describe strategy achieve stereodivergent centers, one fluorine atom, by forming connecting carbon-carbon bond with catalyst system comprising iridium complex that controls at electrophilic carbon copper nucleophilic fluorine-containing carbon. These reactions occur alkyl- aryl-substituted allylic esters unstabilized enolates azaaryl ketones, esters, amides in high yield, diastereoselectivity, enantioselectivity (generally >90% >20:1 dr, 97-99% ee). Access all four stereoisomers products demonstrates precise configurations independently. This methodology extends construction quaternary stereocenters similarly yield selectivity. DFT calculations uncover origin stereoselectivity enolate substitution.

Язык: Английский

---

Stereodivergent Pd/Cu Catalysis for the Dynamic Kinetic Asymmetric Transformation of Racemic Unsymmetrical 1,3-Disubstituted Allyl Acetates

Journal of the American Chemical Society, Год журнала: 2020, Номер 142(18), С. 8097 - 8103

Опубликована: Апрель 19, 2020

A stereodivergent Pd/Cu catalyst system has been developed for the unprecedented dynamic kinetic asymmetric transformation (DyKAT) of racemic unsymmetrical 1,3-disubstituted allylic acetates with prochiral aldimine esters. series α,α-disubstituted α-amino acids bearing vicinal stereocenters were easily prepared excellent enantioselectivities (up to >99% ee) and diastereoselectivities >20:1 dr). Moreover, all four stereoisomers product can be readily obtained simply by switching configurations two chiral metal catalysts. Furthermore, present work highlights power synergistic catalysis consisting common bidentate ligands synthesis.

Язык: Английский

---

Stereodivergent Synthesis of Tertiary Fluoride-Tethered Allenes via Copper and Palladium Dual Catalysis

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(19), С. 7285 - 7291

Опубликована: Май 10, 2021

Herein we describe a protocol for the unprecedented stereodivergent synthesis of tertiary fluoride-tethered allenes bearing stereogenic center and axis via Cu/Pd synergistic catalysis. A broad scope conjugated enynes are coupled with various α-fluoroesters in high yields diastereoselectivities generally >99% ee. In addition, four stereoisomers allene products ensure precise access to corresponding fluorinated hydrofurans novel axial-to-central chirality transfer process.

Язык: Английский

---

Enantio- and Diastereodivergent Construction of 1,3-Nonadjacent Stereocenters Bearing Axial and Central Chirality through Synergistic Pd/Cu Catalysis

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(32), С. 12622 - 12632

Опубликована: Авг. 5, 2021

In contrast to the widely explored methods for asymmetric synthesis of molecules bearing a single stereocenter or adjacent stereocenters, concurrent construction 1,3-stereogenic centers in an enantio- and diastereoselective manner remains challenge, especially acyclic systems. Herein, we report diastereodivergent 1,3-nonadjacent stereocenters allenyl axial central chirality through synergistic Pd/Cu-catalyzed dynamic kinetic allenylation with racemic allenylic esters. The protocol is suitable wide range substrates including challenging esters less sterically bulky substituents provided chiral products high levels diastereoselectivities (up >20:1 dr >99% ee). Furthermore, several representative transformations involving axial-to-central transfer were conducted, affording useful structural motifs containing nonadjacent manner.

Язык: Английский

---

Bimetallic Catalysis in Stereodivergent Synthesis

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(45)

Опубликована: Авг. 2, 2022

Abstract Bimetallic catalysis has emerged as an efficient strategy for the development of new chemical reactions. Importantly, this also provides a simple and powerful platform stereodivergent synthesis, whereby all possible stereoisomers products bearing two stereocenters can be easily prepared from same set starting materials. In Minireview, allylic substitution, propargylic hydrofunctionalization, annulation based on bimetallic been summarized. It is expected that more catalytic systems will developed applied synthesis valuable molecules.

Язык: Английский

---

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

Angewandte Chemie International Edition, Год журнала: 2021, Номер 60(47), С. 24941 - 24949

Опубликована: Сен. 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.

Язык: Английский

---