Photoredox Catalysis in Organic Chemistry

The Journal of Organic Chemistry, Journal Year: 2016, Volume and Issue: 81(16), P. 6898 - 6926

Published: Aug. 1, 2016

In recent years, photoredox catalysis has come to the forefront in organic chemistry as a powerful strategy for activation of small molecules. general sense, these approaches rely on ability metal complexes and dyes convert visible light into chemical energy by engaging single-electron transfer with substrates, thereby generating reactive intermediates. this Perspective, we highlight unique expedite development completely new reaction mechanisms, particular emphasis placed multicatalytic strategies that enable construction challenging carbon–carbon carbon–heteroatom bonds.

Language: Английский

---

Dual Catalysis Strategies in Photochemical Synthesis

Chemical Reviews, Journal Year: 2016, Volume and Issue: 116(17), P. 10035 - 10074

Published: April 25, 2016

The interaction between an electronically excited photocatalyst and organic molecule can result in the genertion of a diverse array reactive intermediates that be manipulated variety ways to synthetically useful bond constructions. This Review summarizes dual-catalyst strategies have been applied synthetic photochemistry. Mechanistically distinct modes photocatalysis are discussed, including photoinduced electron transfer, hydrogen atom energy transfer. We focus upon cooperative interactions photocatalysts with redox mediators, Lewis Brønsted acids, organocatalysts, enzymes, transition metal complexes.

Language: Английский

---

The merger of transition metal and photocatalysis

Nature Reviews Chemistry, Journal Year: 2017, Volume and Issue: 1(7)

Published: July 5, 2017

Language: Английский

---

Organic synthesis provides opportunities to transform drug discovery

Nature Chemistry, Journal Year: 2018, Volume and Issue: 10(4), P. 383 - 394

Published: March 22, 2018

Language: Английский

---

Metallaphotoredox: The Merger of Photoredox and Transition Metal Catalysis

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(2), P. 1485 - 1542

Published: Nov. 18, 2021

The merger of photoredox catalysis with transition metal catalysis, termed metallaphotoredox has become a mainstay in synthetic methodology over the past decade. Metallaphotoredox combined unparalleled capacity for bond formation broad utility photoinduced electron- and energy-transfer processes. Photocatalytic substrate activation allowed engagement simple starting materials metal-mediated bond-forming Moreover, electron or energy transfer directly key organometallic intermediates provided novel modes entirely complementary to traditional catalytic platforms. This Review details contextualizes advancements molecule construction brought forth by metallaphotocatalysis.

Language: Английский

---

Visible‐Light‐Induced Organic Photochemical Reactions through Energy‐Transfer Pathways

Angewandte Chemie International Edition, Journal Year: 2018, Volume and Issue: 58(6), P. 1586 - 1604

Published: May 18, 2018

Abstract Visible‐light photocatalysis is a rapidly developing and powerful strategy to initiate organic transformations, as it closely adheres the tenants of green sustainable chemistry. Generally, most visible‐light‐induced photochemical reactions occur through single‐electron transfer (SET) pathways. Recently, energy‐transfer (EnT) have received considerable attentions from synthetic community this provides distinct reaction pathway, remarkable achievements been made in field. In Review, we highlight recent advances EnT reactions.

Language: Английский

---

Donor–Acceptor Fluorophores for Visible-Light-Promoted Organic Synthesis: Photoredox/Ni Dual Catalytic C(sp³)–C(sp²) Cross-Coupling

ACS Catalysis, Journal Year: 2016, Volume and Issue: 6(2), P. 873 - 877

Published: Jan. 12, 2016

We describe carbazolyl dicyanobenzene (CDCB)-based donor–acceptor (D–A) fluorophores as a class of cheap, easily accessible, and efficient metal-free photoredox catalysts for organic synthesis. By changing the number position cyano groups on center benzene ring, CDCBs with wide range potentials are obtained to effectively drive energetically demanding C(sp3)–C(sp2) cross-coupling carboxylic acids alkyltrifluoroborates aryl halides via photoredox/Ni dual catalysis mechanism. This work validates utility D–A in guiding rational design visible-light-promoted

Language: Английский

---

Single-Electron Transmetalation via Photoredox/Nickel Dual Catalysis: Unlocking a New Paradigm for sp³–sp² Cross-Coupling

Accounts of Chemical Research, Journal Year: 2016, Volume and Issue: 49(7), P. 1429 - 1439

Published: July 5, 2016

The important role of transition metal-catalyzed cross-coupling in expanding the frontiers accessible chemical territory is unquestionable. Despite empowering chemists with Herculean capabilities complex molecule construction, contemporary protocols are not without their Achilles' heel: Csp(3)-Csp(2)/sp(3) coupling. underlying challenge sp(3) cross-couplings 2-fold: (i) methods employing conventional, bench-stable precursors universally reliant on extreme reaction conditions because high activation barrier transmetalation; (ii) circumvention this invariably relies use more reactive precursors, thereby sacrificing functional group tolerance, operational simplicity, and broad applicability. ubiquity problem, nature transmetalation step has remained unchanged from seminal reports Negishi, Suzuki, Kumada, Stille, thus suggesting that challenges coupling result inherent mechanistic constraints traditional paradigm. Rather than submitting to limitations conventional approach, we envisioned a process rooted single-electron reactivity could furnish same key metalated intermediate posited two-electron transmetalation, while demonstrating entirely complementary patterns. Inspired by literature susceptibility organoboron reagents toward photochemical, oxidative fragmentation, realization conceptually novel open shell framework was achieved facile benzylic trifluoroborates aryl halides via cooperative visible-light activated photoredox Ni catalysis. Following study, disclosed suite for secondary alkyl, α-alkoxy, α-amino, α-trifluoromethylbenzyltrifluoroborates. Furthermore, selective Csp(3) moieties presence Csp(2) motifs also demonstrated, highlighting nuances approach transmetalation. Computational modeling mechanism uncovered useful details about intermediates transition-state structures involved nickel catalytic cycle. Most notably, unique dynamic kinetic resolution process, characterized radical homolysis/recombination equilibrium Ni(III) intermediate, discovered. This ultimately found be responsible stereoselectivity an enantioselective variant these cross-couplings. Prompted intrinsic organotrifluoroborates, sought other feedstocks quickly identified alkylbis(catecholato)silicates as viable Ni/photoredox dual These hypervalent silicate species have several notable benefits, including favorable redox potentials allow extension primary alkyl systems incorporating unprotected amines well compatibility less expensive Ru-based photocatalysts. Additionally, exhibit amenability alkenyl halide simultaneously scope. In exploring reagents, serendipitously discovered method effect thioetherification H atom transfer mechanism. latter discovery emphasizes robust paradigm "blind" origins radical, opening opportunities wealth new discoveries. Taken together, our studies area photoredox/nickel catalysis validated powerful platform enabling conventionally challenging Csp(3)-Csp(2) More broadly, findings represent power rational design strategic knowledge manipulation development synthetic methods.

Language: Английский

---

Enantioselective cyanation of benzylic C–H bonds via copper-catalyzed radical relay

Science, Journal Year: 2016, Volume and Issue: 353(6303), P. 1014 - 1018

Published: Sept. 1, 2016

Direct methods for stereoselective functionalization of sp 3 -hybridized carbon–hydrogen [C(sp )–H] bonds in complex organic molecules could facilitate much more efficient preparation therapeutics and agrochemicals. Here, we report a copper-catalyzed radical relay pathway enantioselective conversion benzylic C–H into nitriles. Hydrogen-atom abstraction affords an achiral that undergoes asymmetric C(sp )–CN bond formation upon reaction with chiral copper catalyst. The reactions proceed efficiently at room temperature the substrate as limiting reagent, exhibit broad scope high enantioselectivity (typically 90 to 99% enantiomeric excess), afford products are key precursors important bioactive molecules. Mechanistic studies provide evidence diffusible radicals highlight difference between these oxidations mediated by enzymes other catalysts operate via rebound pathways.

Language: Английский

---

Silyl Radical Activation of Alkyl Halides in Metallaphotoredox Catalysis: A Unique Pathway for Cross-Electrophile Coupling

Journal of the American Chemical Society, Journal Year: 2016, Volume and Issue: 138(26), P. 8084 - 8087

Published: June 6, 2016

A strategy for cross-electrophile coupling has been developed via the merger of photoredox and transition metal catalysis. In this report, we demonstrate use commercially available tris(trimethylsilyl)silane with metallaphotoredox catalysis to efficiently couple alkyl bromides aryl or heteroaryl in excellent yields. We hypothesize that a photocatalytically generated silyl radical species can perform halogen-atom abstraction activate halides as nucleophilic cross-coupling partners. This protocol allows mild yet robust conditions construct Csp(3)-Csp(2) bonds generically unique pathway.

Language: Английский

---