Enantioselective C(sp³)–C(sp³) Reductive Cross-Electrophile Coupling of Unactivated Alkyl Halides with α-Chloroboronates via Dual Nickel/Photoredox Catalysis

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(4), P. 2081 - 2087

Published: Jan. 23, 2023

Substantial advances in enantioconvergent C(sp3)-C(sp3) bond formations have been made with nickel-catalyzed cross-coupling of racemic alkyl electrophiles organometallic reagents or nickel-hydride-catalyzed hydrocarbonation alkenes. Herein, we report an unprecedented enantioselective reductive by the direct utilization two different halides dual nickel/photoredox catalysis system. This highly selective coupling α-chloroboronates and unactivated iodides furnishes chiral secondary boronic esters, which serve as useful important intermediates realm organic synthesis enable a desirable protocol to fast construction enantioenriched complex molecules.

Language: Английский

---

Nickel Chain-Walking Catalysis: A Journey to Migratory Carboboration of Alkenes

Accounts of Chemical Research, Journal Year: 2023, Volume and Issue: 56(22), P. 3246 - 3259

Published: Nov. 1, 2023

ConspectusChain-walking offers extensive opportunities for innovating synthetic methods that involve constructing chemical bonds at unconventional sites. This approach provides previously inaccessible retrosynthetic disconnections in organic synthesis. Through chain-walking, transition metal-catalyzed alkene difunctionalization reactions can take place a 1,n-addition (n ≠ 2) mode. Unlike classical 1,2-regioselective reactions, there remains scarcity of reports regarding migratory patterns. Moreover, the range olefins utilized these studies is quite limited.About five years ago, our research group embarked on project aimed developing valuable alkenes through chain-walking. Our focus was carboboration utilizing nickel catalysis. The reaction commences with insertion an olefin into Ni-Bpin species. Subsequently, thermodynamically stable alkyl complex generated chain-walking process. then couples carbon-based electrophile, leading to formation alkylboron compound. It worth highlighting success transformations relies significantly utilization bisnitrogen-based ligand and LiOMe as B2pin2 activator. Synthetically, establish robust platform rapid efficient synthesis wide structurally diverse organoboron compounds, which are not facially accessed by conventional methods. incorporation versatile boron introduces wealth possibilities subsequent diversifications, enhancing value resulting products allowing creation broader derivatives applications.This Account comprehensive overview efforts advancements field unactivated using We begin outlining development series 1,1-regioselective terminal alkenes. A significant placed initial integration boronate, only triggers metal species but also exerts control over remote stereochemistry involving substituted methylenecyclohexenes. Continuing exploration, remarkable achieved 1,3-regio- cis-stereoselectivity when dealing cyclic Remarkably, catalysis enables heterocyclic be viable coupling partners within transformations. it grants us ability achieve regioselectivity cyclohexenes unattainable, thus expanding horizons regiochemical reactions. Lastly, we present evolution ligand-modulated regiodivergent allylarenes. By gaining insights underlying mechanisms driving regiodivergence, lay strong foundation tackling challenges related selecting specific sites especially multiple factors. anticipate findings, coupled mechanistic we've gained, will advance realm contribute understanding selectivity this nature. advancement catalyze intricate functional molecules, contributing compounds chemistry.

Language: Английский

---

Enantioselective Reductive Cross-Couplings of Olefins by Merging Electrochemistry with Nickel Catalysis

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(44), P. 23910 - 23917

Published: Oct. 26, 2023

The merger of electrochemistry and transition metal catalysis has emerged as a powerful tool to join two electrophiles in an enantioselective manner. However, the development electroreductive cross-couplings olefins remains challenge. Inspired by advantages synergistic use with nickel catalysis, we present here Ni-catalyzed cross-coupling acrylates aryl halides alkyl bromides, which affords chiral α-aryl carbonyls good excellent enantioselectivity. Additionally, this catalytic reaction can be applied (hetero)aryl chlorides, is difficult achieve other methods. combination cyclic voltammetry analysis electrode potential studies suggests that NiI species activates oxidative addition bromides single-electron transfer.

Language: Английский

---

Dual Ni/photoredox-catalyzed asymmetric cross-coupling to access chiral benzylic boronic esters

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: March 12, 2021

Abstract The flourishing Ni/photoredox-catalyzed asymmetric couplings typically rely on redox-neutral reactions. In this work, we report a reductive cross-coupling of aryl iodides and α-chloroboranes under dual catalytic regime to further enrich the metallaphotoredox chemistry. This approach proceeds mild conditions (visible light, ambient temperature, no strong base) access versatile benzylic boronic esters with good functional group tolerance excellent enantioselectivities.

Language: Английский

---

A relay catalysis strategy for enantioselective nickel-catalyzed migratory hydroarylation forming chiral α-aryl alkylboronates

Chem, Journal Year: 2021, Volume and Issue: 7(11), P. 3171 - 3188

Published: Nov. 1, 2021

Language: Английский

---

γ-Selective C(sp3)–H amination via controlled migratory hydroamination

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: Sept. 27, 2021

Abstract Remote functionalization of alkenes via chain walking has generally been limited to C(sp 3 )–H bonds α and β polar-functional units, while γ -C(sp through controlled alkene transposition is a longstanding challenge. Herein, we describe NiH-catalyzed migratory formal hydroamination alkenyl amides achieved chelation-assisted control, whereby various amino groups are installed at the -position aliphatic chains. By tuning olefin isomerization ligand directing group optimization, -selective amination can be stabilization 6-membered nickellacycle by an 8-aminoquinoline subsequent interception aminating reagent. A range amines bond unactivated with varying alkyl lengths, enabling late-stage access value-added -aminated products. Moreover, employing picolinamide-coupled substrates, this approach further extended δ amination. The chain-walking mechanism pathway selectivity investigated experimental computational methods.

Language: Английский

---

Regio- and Stereoselective Alkylboration of Endocyclic Olefins Enabled by Nickel Catalysis

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(48), P. 20027 - 20034

Published: Nov. 4, 2021

Whereas there is a significant interest in the rapid construction of diversely substituted saturated heterocycles, direct and modular access currently limited to mono-, 2,3-, or 3,4-substitution pattern. This Communication describes straightforward 2,4-substituted heterocycles from readily available materials highly stereo- regioselective manner, which sets stage for numerous accessible drug motifs. The strategy relies on chain walking catalysis.

Language: Английский

---

Enantioselective Cobalt-Catalyzed Cascade Hydrosilylation and Hydroboration of Alkynes to Access Enantioenriched 1,1-Silylboryl Alkanes

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(33), P. 13124 - 13134

Published: Aug. 12, 2021

Enantioenriched 1,1-silylboryl alkanes possess silyl and boryl groups that are both connected to the same stereogenic carbon center at well-defined orientations. As these chiral multifunctionalized compounds potentially offer two synthetic handles, they highly valued building blocks in asymmetric synthesis as well medicinal chemistry. Despite potential usefulness, efficient approaches for their preparation scarce. Seeking address this deficiency, an enantioselective cobalt-catalyzed hydrosilylation/hydroboration cascade of terminal alkynes has been realized. This protocol constitutes impressive case chemo-, regio-, stereoselectivity wherein different hydrofunctionalization events exquisitely controlled by a single set metal catalyst ligand, operation which would usually require separate catalytic systems. Downstream transformations enantioenriched 1,1-silyboryl led various valuable compounds. Mechanistic studies suggest present reaction undergoes regioselective stereocontrolled sequential hydrosilylation hydroboration processes.

Language: Английский

---

Catalytic enantioselective reductive domino alkyl arylation of acrylates via nickel/photoredox catalysis

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: Nov. 16, 2021

Abstract Nonsteroidal anti-inflammatory drug derivatives (NSAIDs) are an important class of medications. Here we show a visible-light-promoted photoredox/nickel catalyzed approach to construct enantioenriched NSAIDs via three-component alkyl arylation acrylates. This reductive cross-electrophile coupling avoids preformed organometallic reagents and replaces stoichiometric metal reductants by organic reductant (Hantzsch ester). A broad range functional groups well-tolerated under mild conditions with high enantioselectivities (up 93% ee) good yields 90%). study the reaction mechanism, as well literature precedence, enabled working mechanism be presented. Key steps include reduction bromide radical, Giese addition radical acrylate capture α-carbonyl nickel catalyst. Reductive elimination from proposed Ni(III) intermediate generates product forms Ni(I).

Language: Английский

---

sp³Bis‐Organometallic Reagents via Catalytic 1,1‐Difunctionalization of Unactivated Olefins

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(21), P. 11740 - 11744

Published: Feb. 25, 2021

Abstract A catalytic 1,1‐difunctionalization of unactivated olefins en route to sp 3 bis ‐organometallic B,B(Si)‐reagents is described. The protocol characterized by exceptional reaction rates, mild conditions, wide scope, and exquisite selectivity pattern, constituting a new platform access ‐organometallics.

Language: Английский

---