Alkyl radicals from diacyl peroxides: metal-/base-/additive-free photocatalytic alkylation of N-heteroaromatics

Green Chemistry, Год журнала: 2023, Номер 25(20), С. 7971 - 7977

Опубликована: Янв. 1, 2023

Alkyl diacyl peroxides were demonstrated to be efficient alkylating reagents for the visible-light-induced 4CzIPN-catalyzed direct C–H alkylation of N -heteroaromatics.

Язык: Английский

---

Decatungstate-photocatalyzed direct acylation of N-heterocycles with aldehydes

Green Chemistry, Год журнала: 2024, Номер 26(12), С. 7331 - 7336

Опубликована: Янв. 1, 2024

A novel photocatalytic acylation strategy was developed harnessing tetrabutylammonium decatungstate (TBADT) as a hydrogen atom transfer (HAT) photocatalyst to facilitate the direct coupling of aldehydes with N-heterocycles at ambient temperature.

Язык: Английский

---

Excited Organic Radicals in Photoredox Catalysis

JACS Au, Год журнала: 2025, Номер 5(2), С. 426 - 447

Опубликована: Янв. 29, 2025

Many important synthetic-oriented works have proposed excited organic radicals as photoactive species, yet mechanistic studies raised doubts about whether they can truly function photocatalysts. This skepticism originates from the formation of (photo)redox-active degradation products and picosecond decay electronically radicals, which is considered too short for diffusion-based photoinduced electron transfer reactions. From this perspective, we analyze synthetic transformations where been photocatalysts, comparing their theoretical maximum state potentials with required observed photocatalytic reactivity. We summarize structurally similar photocatalysts indicating different reaction pathways some catalytic systems, addressing cases radical exceed Additionally, perform a kinetic analysis to explain in on subpicosecond time scales. further rationalize potential anti-Kasha reactivity higher states femtosecond lifetimes, highlighting how future photocatalysis advancements could unlock new photochemical pathways.

Язык: Английский

---

Electrophotocatalytic tri- or difluoromethylative cyclization of alkenes

Organic Chemistry Frontiers, Год журнала: 2023, Номер 10(10), С. 2482 - 2490

Опубликована: Янв. 1, 2023

Photoelectrocatalysis is mild yet potent and this work unlocks the potential of unactivated alkenes for oxidant-free oxidative cyclization alkenes.

Язык: Английский

---

Visible-Light-Mediated Photoredox Carbon Radical Formation from Aqueous Sulfoxonium Ylides

Organic Letters, Год журнала: 2023, Номер 25(7), С. 1161 - 1165

Опубликована: Фев. 9, 2023

The visible-light-induced photoredox carbon radical formation from aqueous sulfoxonium ylides has been demonstrated for the first time. While direct reduction of by H2O efficiently generates corresponding hydrocarbon compounds, use additional alkenes as acceptors alters chemical reactivity to achieve alkene carboarylation N-arylacrylamides. Mechanistic studies reveal two different reaction pathways involved in resulting release dimethyl sulfone and form DMSO.

Язык: Английский

---

Catalytic Asymmetric Redox‐Neutral [3+2] Photocycloadditions of Cyclopropyl Ketones with Vinylazaarenes Enabled by Consecutive Photoinduced Electron Transfer

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(30)

Опубликована: Апрель 30, 2024

Abstract Consecutive photoinduced electron transfer (ConPET) is a powerful and atom‐economical protocol to overcome the limitations of intrinsic redox potential visible light‐absorbing photosensitizers, thereby considerably improving substrate reaction types. Likely because such an exothermic single‐electron (SET) process usually does not require aid chiral catalysts, resulting in inevitable racemic background reaction, notably, no enantioselective manifolds have been reported. Herein, we report on viability cooperative ConPET hydrogen‐bonding catalysis for [3+2] photocycloaddition cyclopropyl ketones with vinylazaarenes. In addition enabling first use olefins that preferentially interact this platform paves way efficient synthesis pharmaceutically synthetically important cyclopentyl functionalized by azaarenes high yields, ees dr. The robust capacity method can be further highlighted low loading catalyst (1.0 mol %), good compatibility both 2‐azaarene 3‐pyridine‐based olefins, successful concurrent construction three stereocenters cyclopentane rings involving elusive but all‐carbon quaternary.

Язык: Английский

---

Catalytic asymmetric photocycloaddition reactions mediated by enantioselective radical approaches

Chemical Society Reviews, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

The use of olefins in the construction cyclic compounds represents a powerful strategy for advancing pharmaceutical industry.

Язык: Английский

---

Unlocking the ConPeT Mechanism: Correspondence on “Catalytic Asymmetric Redox‐Neutral [3 + 2] Photocycloadditions of Cyclopropyl Ketones with Vinylazaarenes Enabled by Consecutive Photoinduced Electron Transfer”

Angewandte Chemie International Edition, Год журнала: 2025, Номер unknown

Опубликована: Март 21, 2025

Recently, in a communication to this journal, Qiao, Jang, and coworkers described an asymmetric photoredox reaction promoted by TADF cyanoarene photocatalysts (specifically 4DPAPN (3,4,5,6-tetrakis(diphenylamino)phthalonitrile)). The authors claimed that the high reduction potential required for acetonitrile was achieved radical anion of photocatalyst its excited state, which initiated reaction. This mechanism is usually named consecutive photoinduced electron transfer (ConPeT), two photons are involved: first one excite generate 4DPAPN•- second photon promote state *4DPAPN•-. Employing ultrafast transient absorption spectroscopy, here we report that, although indeed involved transformation, *4DPAPN•- short-lived, not emissive, quenched organic substrate employed reaction, opposite what authors. can solvated able reduce chemistry. It worth noting different photochemical likely be operative CH2Cl2, where electrons much less stabilized solvent might occur.

Язык: Английский

---

Radical-mediated photoredox hydroarylation with thiosulfonate

Chemical Communications, Год журнала: 2023, Номер 59(19), С. 2767 - 2770

Опубликована: Янв. 1, 2023

Radical-mediated photoredox hydroarylation reaction of unactivated alkenes using thiosulfonate compounds as key radical precursors to synthesize pyridyquinazolinone and pyrroloquinazolinone derivatives is described.

Язык: Английский

---

Visible-Light-Induced Cascade Arylazidation of Activated Alkenes with Trimethylsilyl Azide

Organic Letters, Год журнала: 2023, Номер 25(27), С. 5162 - 5167

Опубликована: Июнь 29, 2023

A visible-light-induced cascade arylazidation of activated alkenes with trimethylsilyl azide (TMSN3) has been developed. Mechanistic investigations reveal that the single electron transfer (SET) TMSN3 excited photocatalyst was involved in initial step, followed by radical addition/aryl migration/desulfonylation to furnish valuable α-aryl-β-azido amides and azidated oxindoles under mild conditions, which are versatile building blocks organic synthesis. With simple treatment, obtained arylazidated products were further converted β-amino amide 1,2,3-triazole derivatives.

Язык: Английский

---