Modular Access to Chiral α-(Hetero)aryl Amines via Ni/Photoredox-Catalyzed Enantioselective Cross-Coupling

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(19), P. 8797 - 8806

Published: May 3, 2022

Chiral α-aryl N-heterocycles are commonly found in natural products, pharmaceutical agents, and chiral catalysts but remain challenging to access via asymmetric catalysis. Herein, we report a general modular approach for the direct enantioselective α-arylation of saturated azacycles acyclic N-alkyl benzamides nickel/photoredox dual This process exploits hydrogen atom transfer ability photoeliminated chlorine radicals convert corresponding α-amino alkyl that then coupled with ubiquitous inexpensive (hetero)aryl chlorides. These coupling reactions require no oxidants or organometallic reagents, feature feedstock starting materials, broad substrate scope, high enantioselectivities, applicable late-stage diversification medicinally relevant complex molecules. Mechanistic studies suggest nickel catalyst uncommonly plays multiple roles, accomplishing radical generation, capture, cross-coupling, induction.

Language: Английский

---

Nickel-Catalyzed Enantioselective Electrochemical Reductive Cross-Coupling of Aryl Aziridines with Alkenyl Bromides

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(11), P. 6270 - 6279

Published: March 7, 2023

An electrochemically driven nickel-catalyzed enantioselective reductive cross-coupling of aryl aziridines with alkenyl bromides has been developed, affording enantioenriched β-aryl homoallylic amines excellent E-selectivity. This electroreductive strategy proceeds in the absence heterogeneous metal reductants and sacrificial anodes by employing constant current electrolysis an undivided cell triethylamine as a terminal reductant. The reaction features mild conditions, remarkable stereocontrol, broad substrate scope, functional group compatibility, which was illustrated late-stage functionalization bioactive molecules. Mechanistic studies indicate that this transformation conforms stereoconvergent mechanism aziridine is activated through nucleophilic halide ring-opening process.

Language: Английский

---

Photoinduced Cobalt-Catalyzed Desymmetrization of Dialdehydes to Access Axial Chirality

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(12), P. 6944 - 6952

Published: March 15, 2023

Enantioselective metallaphotoredox catalysis, which combines photoredox catalysis and asymmetric transition-metal has become an effective approach to achieve stereoconvergence under mild conditions. Although many impressive synthetic approaches have been developed access central chirality, the construction of axial chirality by still remains underexplored. Herein, we report two visible light-induced cobalt-catalyzed reductive couplings biaryl dialdehydes synthesize axially chiral aldehydes (60 examples, up 98% yield, >19:1 dr, >99% ee). This protocol shows good functional group tolerance, broad substrate scope, excellent diastereo- enantioselectivity.

Language: Английский

---

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

---

Desymmetrization–Addition Reaction of Cyclopropenes to Imines via Synergistic Photoredox and Cobalt Catalysis

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(28), P. 18892 - 18898

Published: July 5, 2024

Herein, we designed a reaction for the desymmetrization-addition of cyclopropenes to imines by leveraging synergy between photoredox and asymmetric cobalt catalysis. This protocol facilitated synthesis series chiral functionalized cyclopropanes with high yield, enantioselectivity, diastereoselectivity (44 examples, up 93% yield >99% ee). A possible mechanism involving cyclopropene desymmetrization Co-H species imine addition Co-alkyl was proposed. study provides novel route important extends frontier metallaphotoredox

Language: Английский

---

Three-component enantioselective alkenylation of organophosphonates via nickel metallaphotoredox catalysis

Chem, Journal Year: 2022, Volume and Issue: 9(1), P. 154 - 169

Published: Oct. 14, 2022

Language: Английский

---

Synthesis of P-stereogenic cyclicphosphinic amidesviaelectrochemically enabled cobalt-catalyzed enantioselective C–H annulation

Green Chemistry, Journal Year: 2023, Volume and Issue: 25(9), P. 3606 - 3614

Published: Jan. 1, 2023

We describe a cobalta-electro-catalyzed enantioselective C–H annulation of arylphosphinamides with alkynes for P-stereogenic compounds via desymmetrization and kinetic resolution processes.

Language: Английский

---

Regio- and Stereoselective Reductive Coupling of Alkynes and Crotononitrile

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(50), P. 23001 - 23009

Published: Dec. 8, 2022

A new regio- and stereoselective reductive coupling of alkynes crotononitrile has been developed via visible light organophotoredox cobalt dual catalysis. variety enantioenriched homoallylic nitriles bearing a stereodefined trisubstituted alkene have easily synthesized with good to excellent (up >20:1 rr), stereo- (>20:1 E/Z), enantioselectivity 98% ee) control under mild conditions. The corresponding nitrile products were smoothly converted into various chiral building blocks. Remarkably, simple organic base together water utilized as hydrogen sources in this photoinduced reaction.

Language: Английский

---

A general copper-catalysed enantioconvergent radical Michaelis–Becker-type C(sp3)–P cross-coupling

Nature Synthesis, Journal Year: 2023, Volume and Issue: 2(5), P. 430 - 438

Published: Feb. 23, 2023

Language: Английский

---

Metal-Catalyzed Enantioconvergent Transformations

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(20), P. 11817 - 11893

Published: Oct. 4, 2023

Enantioconvergent catalysis has expanded asymmetric synthesis to new methodologies able convert racemic compounds into a single enantiomer. This review covers recent advances in transition-metal-catalyzed transformations, such as radical-based cross-coupling of alkyl electrophiles with nucleophiles or alkylmetals and reductive two mainly under Ni/bis(oxazoline) catalysis. C–H functionalization can be performed an enantioconvergent manner. Hydroalkylation alkenes, allenes, acetylenes is alternative reactions. Hydrogen autotransfer been applied amination alcohols C–C bond forming reactions (Guerbet reaction). Other metal-catalyzed involve addition allylic systems carbonyl compounds, propargylation phenols, 3-bromooxindoles, allenylation allenolates propargyl bromides, hydroxylation 1,3-dicarbonyl compounds.

Language: Английский

---