Nitrogen-Centered Radicals in Functionalization of sp² Systems: Generation, Reactivity, and Applications in Synthesis

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(9), P. 8181 - 8260

Published: March 14, 2022

The chemistry of nitrogen-centered radicals (NCRs) has plentiful applications in organic synthesis, and they continue to expand as our understanding these reactive species increases. utility intermediates is demonstrated the recent advances C–H amination (di)amination alkenes. Synthesis previously challenging structures can be achieved by efficient functionalization sp2 moieties without prefunctionalization, allowing for faster more streamlined synthesis. This Review addresses generation, reactivity, application NCRs, including, but not limited to, iminyl, aminyl, amidyl, aminium species. Contributions from early discovery up most examples have been highlighted, covering radical initiation, thermolysis, photolysis, and, recently, photoredox catalysis. Radical-mediated intermolecular (hetero)arenes occur with a variety complex amine precursors, generating aniline derivatives, an important class drug development. Functionalization olefins achievable high anti-Markovnikov regioselectivity allows access difunctionalized when intermediate carbon are trapped. Additionally, reactivity NCRs harnessed rapid construction N-heterocycles such pyrrolidines, phenanthridines, quinoxalines, quinazolinones.

Language: Английский

---

Electro-/photocatalytic alkene-derived radical cation chemistry: recent advances in synthetic applications

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(16), P. 7206 - 7237

Published: Jan. 1, 2022

This review covers the recent progress in electro-/photo-catalytic alkene-derived radical cation chemistry for organic synthesis, including synthetic strategies, plausible mechanisms and further research outlook.

Language: Английский

---

Arenethiolate as a Dual Function Catalyst for Photocatalytic Defluoroalkylation and Hydrodefluorination of Trifluoromethyls

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(7), P. 4103 - 4109

Published: March 18, 2022

Thiol is known to act as a hydrogen atom transfer catalyst working in synergy with photocatalyst photoredox catalysis, but we report herein that an arene thiolate appropriate substituent can be photoactivated under visible light function both strongly reducing electron-donating redox and HAT enable catalytic C–F activation of trifluoromethyl substrates for selective hydrodefluorination coupling various alkenes the presence formate salts. These reactions demonstrate promising utility arenethiolates dual photocatalysts. The synthetic this method demonstrated by broad scope amenable substrates, including trifluoromethylated (hetero)arenes, trifluoroacetates, trifluoroacetamides, which exhibited high levels chemoselectivity. reaction efficacy allows site-selective late-stage functionalization multitrifluoromethylated bioactive compounds pharmaceuticals

Language: Английский

---

Progression of Hydroamination Catalyzed by Late Transition-Metal Complexes from Activated to Unactivated Alkenes

Accounts of Chemical Research, Journal Year: 2023, Volume and Issue: 56(12), P. 1565 - 1577

Published: June 5, 2023

ConspectusCatalytic intermolecular hydroamination of alkenes is an atom- and step-economical method for the synthesis amines, which have important applications as pharmaceuticals, agrochemicals, catalysts, materials. However, hydroaminations in high yield with selectivity are challenging to achieve because these reactions often lack a thermodynamic driving force accompanied by side reactions, such alkene isomerization, telomerization, oxidative amination. Consequently, early examples were generally limited additions N-H bonds conjugated or strained alkenes, catalytic unactivated late transition metals has only been disclosed recently. Many classes including metals, rare-earth acids, photocatalysts, reported hydroamination. Among them, transition-metal complexes possess several advantages, their relative ease handling compatibility substrates containing polar sensitive functional groups.This Account describes progression our laboratory catalyzed from initial activated more recent alkenes. Our developments include Markovnikov anti-Markovnikov vinylarenes palladium, rhodium, ruthenium, dienes trienes nickel hydroanimation bicyclic neutral iridium, terminal internal cationic iridium ruthenium. Enantioselective form enantioenriched, chiral amines also developed.Mechanistic studies elucidated elementary steps turnover-limiting reactions. The nickel, ruthenium occurs nucleophilic attack amine on coordinated benzyl, allyl, alkene, arene ligand. On other hand, unconjugated migratory insertion into metal-nitrogen bond. In addition, pathways formation products, isomeric enamines, identified during studies. During enantioselective hydroamination, reversibility shown erode enantiopurity products. Based mechanistic understandings, new generations catalysts that promote higher rates, chemoselectivity, enantioselectivity developed. We hope discoveries insights will facilitate further development selective, practical, efficient

Language: Английский

---

Energy-transfer-induced [3+2] cycloadditions of N–N pyridinium ylides

Nature Chemistry, Journal Year: 2023, Volume and Issue: 15(8), P. 1091 - 1099

Published: June 26, 2023

Language: Английский

---

Energy- and atom-efficient chemical synthesis with endergonic photocatalysis

Nature Reviews Chemistry, Journal Year: 2022, Volume and Issue: 6(10), P. 745 - 755

Published: Sept. 23, 2022

Language: Английский

---

Photocatalytic Late-Stage Functionalization of Sulfonamides via Sulfonyl Radical Intermediates

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(10), P. 6060 - 6067

Published: May 6, 2022

A plethora of drug molecules and agrochemicals contain the sulfonamide functional group. However, sulfonamides are seldom viewed as synthetically useful groups. To confront this limitation, a late-stage functionalization strategy is described, which allows to be converted pivotal sulfonyl radical intermediates. This methodology exploits metal-free photocatalytic approach access chemistry, harnessed by combining pharmaceutically relevant with an assortment alkene fragments. Additionally, sulfinate anion can readily obtained, further broadening options for functionalization. Mechanistic studies suggest that energy-transfer catalysis (EnT) in operation.

Language: Английский

---

Recent advances in visible light-induced C(sp3)–N bond formation

Nature Reviews Chemistry, Journal Year: 2022, Volume and Issue: 6(8), P. 544 - 561

Published: July 11, 2022

Language: Английский

---

Recent Advances in C–H Functionalisation through Indirect Hydrogen Atom Transfer

Molecules, Journal Year: 2023, Volume and Issue: 28(16), P. 6127 - 6127

Published: Aug. 18, 2023

The functionalisation of C–H bonds has been an enormous achievement in synthetic methodology, enabling new retrosynthetic disconnections and affording simple equivalents for synthons. Hydrogen atom transfer (HAT) is a key method forming alkyl radicals from substrates. Classic reactions, including the Barton nitrite ester reaction Hofmann–Löffler–Freytag reaction, among others, provided early examples HAT. However, recent developments photoredox catalysis electrochemistry have made HAT powerful tool capable introducing wide range functional groups into bonds. Moreover, greater mechanistic insights stimulated development increasingly site-selective protocols. Site-selectivity can be achieved through tuning electron density at certain using additives, judicious choice reagent, solvent system. Herein, we describe latest methods functionalizing C–H/Si–H/Ge–H indirect between 2018–2023, as well critical discussion reagents, aspects, substrate scopes, background contexts

Language: Английский

---

Radical thioesterification via nickel-catalysed sensitized electron transfer

Nature Synthesis, Journal Year: 2023, Volume and Issue: 2(11), P. 1116 - 1126

Published: July 10, 2023

Abstract Multi-catalytic reaction modes have attracted widespread attention in synthetic chemistry. The merger of nickel catalysis with photoredox has offered a powerful platform for synthesis molecules attractive properties. Nonetheless, the conceptual development nickel-catalysed, sensitized electron transfer is pivotal relevance, but still greatly limited. Here we describe radical cross-thioesterification process by nickel-catalysed transfer. strategy can produce diverse methyl thioesters, which are not only found natural products, materials and pharmaceuticals also precursors chemistry biological processes. This catalytic mode features high chemoselectivity, good functional group tolerance excellent scalability. Perhaps more important was finding that various drugs amino acids were successfully functionalized this system. Experimental studies, nanosecond transient spectroscopic analysis, density theory calculations reveal photocatalytic transfer, energy plays an essential role thioesterification reaction.

Language: Английский

---