Photoredox-Catalyzed Defluorinative Carboxylation of gem-Difluorostyrenes with Formate Salt

Organic Letters, Journal Year: 2024, Volume and Issue: 26(4), P. 883 - 888

Published: Jan. 22, 2024

Herein, we present a transition-metal-free, easy handling protocol for regioselective carboxylation of gem-difluorostyrenes with sodium formate as the C1 source. 30 examples α-fluoracrylates were obtained in yields to 80% under these conditions. A defluorinative monofluorovinyl intermediate and consecutive photoinduced electron transfer mechanism proposed after investigation.

Language: Английский

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Dataset Design for Building Models of Chemical Reactivity

ACS Central Science, Journal Year: 2023, Volume and Issue: 9(12), P. 2196 - 2204

Published: Dec. 8, 2023

Models can codify our understanding of chemical reactivity and serve a useful purpose in the development new synthetic processes via, for example, evaluating hypothetical reaction conditions or silico substrate tolerance. Perhaps most determining factor is composition training data whether it sufficient to train model that make accurate predictions over full domain interest. Here, we discuss design datasets ways are conducive data-driven modeling, emphasizing idea set diversity generalizability rely on choice molecular representation. We additionally experimental constraints associated with generating common types chemistry how these considerations should influence dataset building.

Language: Английский

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Photodriven Radical-Polar Crossover Cyclization Strategy: Synthesis of Pyrazolo[1,5-a]pyridines from Diazo Compounds

Organic Letters, Journal Year: 2024, Volume and Issue: 26(12), P. 2511 - 2516

Published: March 20, 2024

This work demonstrates the synthesis of a variety perfluoroalkyl heterocycles via visible-light-driven radical-polar crossover cyclization strategy. In this process, single-electron reduction/SNV-type/cyclization sequences follow radical addition reaction diazoester, which differs from current role diazoesters as precursors/acceptors. transformation excellent functional group compatibility and allows for modification many bioactive molecules with diazoesters. Such could represent novel approach to photochemical diazo compounds.

Language: Английский

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Recent Advances in Cyclization Reactions of 1,6‐Enynes

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(6), P. 1220 - 1268

Published: Jan. 22, 2024

Abstract Elaborated molecular architectures, specifically those bearing one or more carbon stereocenters, stand as an important class of carbocyclic and heterocyclic frameworks because they are frequently occurring core structures in numerous natural products biologically active pharmaceutical molecules. Over the past few decades, development versatile synthetic approaches via cascade cyclization reactions 1,6‐enynes for construction a series fused spiro compounds has been focus great deal research initiatives. These synthesis strategies peculiarly fascinating context assembly wide array molecules, products, agrochemicals, functional materials. In this review, recent developments transformations with diverse coupling reagents summarized since 2018, which could be divided into five categories: 1) Introduction; 2) Transition metal catalyzed 1,6‐enynes; 3) Metal‐free 4) Visible‐light‐induced 5) Electrocatalytic 1,6‐enynes.

Language: Английский

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Shamrock‐Shaped D₂–A–Cz Materials Featuring Trifluoromethyl Carbazole and Pyrimidine: a Tailored Host for Green Phosphorescent OLEDs

Advanced Materials Technologies, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 25, 2025

Abstract A new class of shamrock‐shaped D 2 –A–Cz and –A–D′ bipolar host materials is specifically designed to optimize performance in green phosphorescent organic light‐emitting diode (OLED) devices. These utilize 3,6‐bis(trifluoromethyl)‐9 H ‐carbazole ( CF 3 Cz ) as the donor (D), pyrimidine (Pym) or pyridine (Py) acceptor, with features structural modifications aimed at enhancing stability luminescence efficiency. In particular, introduction strong electron‐withdrawing groups helps stabilize highest occupied molecular orbital (HOMO) energy level, while electron‐donating like tert ‐butyl group, carbazole, N,N ‐dimethylamine destabilize lowest unoccupied (LUMO), resulting high triplet levels crucial for OLED performance. Cz–2CzPym exhibits outstanding electroluminescent properties when doped Ir(ppy) , achieving a maximum external quantum efficiency (EQE) 18.5% luminance 64.6 cd −1 low turn‐on voltage 2.6 V. Additionally, combined electron‐transporting material bis‐4,6‐(3,5‐di‐3‐pyridylphenyl)‐2‐methylpyrimidine (B3PyMPM) form co‐host system, these further improve charge balance efficiency, attaining EQE 19.8% peak 68.4 . The substituents 6 positions carbazole firmly stabilizes frontier orbitals energy.

Language: Английский

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Photocatalytic Cyclization Cascades by Radical Relay toward Pyrrolo[1,2-a]indoles: Synthesis, Mechanism, and Application

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(5), P. 3509 - 3524

Published: Feb. 16, 2024

A photocatalytic annulation cascade of unactivated N-alkene-linked indoles with Langlois' reagent by a radical relay is developed at room temperature under blue LED irradiation. The reaction afforded series tri/difluoromethylated pyrrolo[1,2-a]indoles in moderate to good yields. DFT study suggests that the ascribed rhodamine 6G-induced cyclization involving vinyl addition-radical and hydrogen-atom-abstraction (HAA) processes, interestingly, are applied as fluorescent dyes into fluorescence spectrum live-cell imaging. This paper represents an initial example on cascades HAA process.

Language: Английский

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Radical reactions enabled by polyfluoroaryl fragments: photocatalysis and beyond

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(9), P. 4741 - 4785

Published: Jan. 1, 2024

The review summarizes advances in the radical chemistry of polyfluorinated arenes under photocatalytic conditions. fluoroaryl fragment serves as enabling motif for reaction design and efficient generation reactive intermediates.

Language: Английский

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Standardizing Substrate Selection: A Strategy toward Unbiased Evaluation of Reaction Generality

ACS Central Science, Journal Year: 2024, Volume and Issue: unknown

Published: April 8, 2024

With over 10,000 new reaction protocols arising every year, only a handful of these procedures transition from academia to application. A major reason for this gap stems the lack comprehensive knowledge about reaction's scope, i.e., which substrates protocol can or cannot be applied. Even though chemists invest substantial effort assess scope protocols, resulting tables involve significant biases, reducing their expressiveness. Herein we report standardized substrate selection strategy designed mitigate biases and evaluate applicability, as well limits, any chemical reaction. Unsupervised learning is utilized map space industrially relevant molecules. Subsequently, potential candidates are projected onto universal map, enabling structurally diverse set with optimal relevance coverage. By testing our methodology on different reactions, were able demonstrate its effectiveness in finding general reactivity trends by using few highly representative examples. The developed empowers showcase unbiased applicability novel methodologies, facilitating practical applications. We hope that work will trigger interdisciplinary discussions synthetic chemistry, leading improved data quality.

Language: Английский

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Visible‐Light‐Driven Four‐Component Radical Relay Aminocarbonylation of Unactivated Alkenes^†

Chinese Journal of Chemistry, Journal Year: 2024, Volume and Issue: 42(9), P. 990 - 996

Published: Jan. 18, 2024

Comprehensive Summary Catalytic four‐component radical carbonylation of unactivated alkenes has recently been recognized as a robust protocol for rapid construction various structurally diverse carbonyl compounds. Given the significance fluorine‐containing groups, this reaction class extensively applied to assembly variety perfluoroalkyl carboxylic acid derivatives by transition metal catalysis. Herein, we report visible‐light‐driven relay 1,2‐perfluoroalkylation aminocarbonylation using CO gas source and 4CzIPN organic photocatalyst. A wide range amines were well tolerated, providing valuable β‐perfluoroalkylated amides with generally good yields high chemoselectivity.

Language: Английский

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Iridium Photoredox-Catalyzed Stereoselective C-Glycosylation with Tetrafluoropyridin-4-yl Thioglycosides: A Facile Synthesis of C-α/β-Glucogallins and Their Antioxidant Activity

ACS Catalysis, Journal Year: 2024, Volume and Issue: unknown, P. 17727 - 17738

Published: Nov. 18, 2024

We demonstrate an efficient, scalable, and stereoselective C-glycosylation with thioglycosides possessing a unique photoactive tetrafluoropyridin-4-yl (TFPy) thio radical leaving group, affording editable medicinally biologically essential C-α-glucogallin derivatives. In the presence of silyl enol ether acceptors, desulfurative coupling reaction performs smoothly under mild conditions upon exposure to blue light irradiation. This versatile protocol permits synthesis sugar-drug chimeras by C1 ketonylation complex drug-derived ethers. The scale-up synthesis, anomeric epimerization, post-C-glycosylation modification ketone sugars showcase reaction's potential utilities. Furthermore, could be applied direct carbohydrate skeleton editing equipping group on nonanomeric position. is viable for unprotected TFPy thioglycoside, route ketonyl sugars. concise six-step assembly both configurated C-glucogallins from commercially cheap glucose pentaacetate their antioxidant reactivity investigations underline promising medicinal relevance our current protocols. mechanism was investigated through trapping experiment, oxocarbenium fluorescence quenching Stern–Volmer analysis, confirming that major glycosyl intermediates are generated thioglycoside donors, whose effectively quench excited Ir(ppy)3 oxidative process, complementary product, accounting examples moderate selectivities.

Language: Английский

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