Nickel-Catalyzed Reductive Allylation of Aldehydes with Allylic Alcohols in the Presence of CO₂

Organic Letters, Journal Year: 2023, Volume and Issue: 25(45), P. 8178 - 8182

Published: Nov. 7, 2023

CO2-assisted and Ni-catalyzed direct reductive allylation of aldehydes utilizing allylic alcohols as precursor has been reported. Various homoallyl could be synthesized in excellent yield with enhanced regioselectivity stereoselectivity for alkyl- aryl-substituted under mild conditions. For different substrates, proper collocation the catalytic ligand is crucial. Preliminary mechanistic studies supported reaction pathway through a sequential allyl hydrocarbonate formation/allylnickelation/coordination insertion process by Ni(I)/Ni(III) cycle, which proven cyclic voltammetry analysis.

Language: Английский

---

Allenyl Carbonate as a Butadiene Surrogate in Cobalt-Catalyzed Crotylation of Aldehydes

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(9), P. 5893 - 5899

Published: April 18, 2023

Allenyl carbonate was used as a 1,3-butadiene surrogate to develop photocatalytically sustainable protocol for cobalt-catalyzed crotylation of aldehydes. The developed method tolerated wide range aromatic and aliphatic aldehydes with retention functional groups under mild conditions produced good-to-excellent yields crotylated secondary alcohols. Based on preliminary mechanistic studies literature precedents, plausible mechanism is proposed.

Language: Английский

---

Recent progress in stereoselective transformations enabled by thermally activated delayed fluorescence photocatalysts

Chem Catalysis, Journal Year: 2024, Volume and Issue: 4(5), P. 100915 - 100915

Published: Feb. 2, 2024

Language: Английский

---

Nickel-Catalyzed Regioselective Hydrothiolation of Allenes Enabled by Visible-Light Photoredox Catalysis

Organic Letters, Journal Year: 2024, Volume and Issue: 26(21), P. 4438 - 4442

Published: May 20, 2024

Hydrothiolation presents an attractive way to transform allenes into allylic thioethers. Herein, we described efficient visible-light photoredox-promoted nickel-catalyzed hydrothiolation of with functionalized aromatic and aliphatic thiols. This synergistic catalytic system exhibits unprecedentedly high reactivities regiocontrol for the construction thioethers, representing unique synthetic utility earth-abundant Ni-catalyzed method compared related noble-metal-catalyzed allylation reactions.

Language: Английский

---

Radical Allylation of Aldehydes with Allenes by Photoredox Cobalt and Chromium Dual Catalysis

Synthesis, Journal Year: 2024, Volume and Issue: 56(16), P. 2558 - 2564

Published: May 23, 2024

Abstract A dual cobalt and chromium photoredox-catalyzed allylation of aldehydes with allenes through a photo metal-hydride atom transfer (MHAT) process has been developed to yield homoallylic alcohols exceptional diastereoselective control. This sustainable efficient method holds significant promise for applications in the synthesis valuable organic compounds.

Language: Английский

---

Photoredox/Nickel Dual-Catalyzed Allylation of Aldehydes with Allylic Alcohols and Mechanistic Insights in the Presence of CO₂

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(16), P. 12392 - 12402

Published: Aug. 5, 2024

Direct utilization of allylic alcohols as reagents without metal reductants has drawn significant attention. Herein, we report a practical, diastereoselective photoredox/Ni(II)-dual-catalyzed reductive allylation reaction aldehydes with readily accessible in the presence CO2. This methodology allows branched regioselective direct wide range various good to high yield and up >20:1 d.r. ratio. Accurate DFT calculations revealed rationale behind diastereoselectivity differences via Zimmerman–Traxler transition state for different substrates, while also delineated energetically most favorable mechanistic pathway this reaction.

Language: Английский

---

Harnessing the potential of acyl triazoles in bifunctional cobalt-catalyzed radical cross-coupling reactions

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Aug. 13, 2024

Persistent radicals facilitate numerous selective radical coupling reactions. Here, we have identified acyl triazole as a new and versatile moiety for generating persistent intermediates through single-electron transfer processes. The efficient generation of these is facilitated by the formation substrate-coordinated cobalt complexes, which subsequently engage in cross-coupling Remarkably, triazole-coordinated complexes exhibit metal-hydride hydrogen atom (MHAT) capabilities with alkenes, enabling synthesis diverse ketone products without need external ligands. By leveraging effect, this catalytic approach also allows development other reactions two representative precursors. discovery triazoles effective substrates ligands catalysis, combined bifunctional nature system, opens up avenues design sustainable organic transformations. radical-mediated has emerged powerful tool forging C–C bonds. authors identify processes, context cobalt-catalysed carbon-carbon couplings under photoirradiation.

Language: Английский

---

Photochemical Asymmetric Palladium-Catalyzed Allylation Reaction: Expeditious Entry to Chiral 1,2-Amino Alcohols and 1,2-Diamines

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(17), P. 13352 - 13361

Published: Aug. 23, 2024

The construction of diverse alkyl amines is importance in drug discovery and natural product synthesis. Herein, we report an efficient photoredox/palladium dual catalysis for the protected 1,2-amino alcohols 1,2-diamines via asymmetric allylation α-silyl with heteroatom-substituted allenes 1,3-dienes. This protocol characterized by its mild conditions, high regio- enantioselectivities, wide substrate scope, including aliphatic or N-heterocyclic substrates especially. Computational experimental mechanistic studies indicate that reaction proceeds through a sequence oxidative addition Pd(0) catalyst PPTS, allene insertion, outer-sphere radical substitution-type C–C bond formation, reduction Pd(I) Ir(II). Thereinto, substitution enantio- regioselectivity determining step.

Language: Английский

---

Radical‐Based Enantioconvergent Reductive Couplings of Racemic Allenes and Aldehydes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 64(1)

Published: Sept. 2, 2024

Abstract Transition metal‐catalyzed radical‐based enantioconvergent reactions have become a powerful strategy to synthesize enantiopure compounds from racemic starting materials. However, existing methods primarily address precursors with central chirality, neglecting those axial chirality. Herein, we describe the reductive coupling of allenes aldehydes, facilitated by photoredox, chromium, and cobalt triple catalysis system. This method selectively affords one product sixteen possible regio‐ stereoisomers. The protocol leverages Co III −H mediated hydrogen atom transfer (MHAT) Cr‐catalyzed radical‐polar crossover for efficient stereoablation chirality asymmetric addition, respectively. Supported mechanistic insights control experiments, deuterium labeling, DFT calculations, our approach offers synthetic chemists valuable tool creating enantioenriched chiral homoallylic alcohols, promising advance strategies synthesizing complex molecules.

Language: Английский

---

Redox-neutral synthesis of π-allylcobalt complexes from alkenes for aldehyde allylation via photoredox catalysis

Green Chemistry, Journal Year: 2022, Volume and Issue: 24(23), P. 9027 - 9032

Published: Jan. 1, 2022

This work reports the first visible-light mediated cobalt-catalyzed aldehyde allylation with simple alkenes to produce homo-allylic alcohols. novel strategy directly uses easily available unactivated as allyl sources instead of pre-synthesized allylic halides.

Language: Английский

---