Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(10), P. 2634 - 2639
Published: Jan. 1, 2022
By using ammonia as a hydrogen source, electrochemical pyridylation of unsaturated compounds is achieved with more than 50 examples. In particular, the β-keto ester could be converted to corresponding tertiary β-hydroxyl for first time.
Language: Английский
eScience, Journal Year: 2022, Volume and Issue: 2(3), P. 243 - 277
Published: April 23, 2022
Compared with general redox chemistry, electrochemistry using the electron as a potent, controllable, yet traceless alternative to chemical oxidants/reductants usually offers more sustainable options for achieving selective organic synthesis. With its environmentally benign features gradually being uncovered and studied, electrosynthesis is currently undergoing revival becoming rapidly growing area within synthetic community. Among electrochemical transformations, anodically enabled ones have been far extensively exploited than those driven by cathodic reduction, although both approaches are conceptually attractive. To stimulate development of cathodically reactions, this review summarizes recently developed reductive electrosynthetic protocols, discussing highlighting reaction features, substrate scopes, applications, plausible mechanisms reveal recent trends in area. Herein, reduction-enabled preparative transformations categorized into four types: reduction (1) unsaturated hydrocarbons, (2) heteroatom-containing carbon-based systems, (3) saturated C-hetero or C–C polar/strained bonds, (4) hetero-hetero linkages. Apart from net electroreductive few examples photo-electrosynthesis well paired electrolysis also introduced, which offer opportunities overcome certain limitations improve versatility. The electrochemically driven, transition metal-catalyzed cross-couplings that comprehensively discussed several other reviews not included here.
Language: Английский
Citations
140
Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(4), P. 1899 - 1909
Published: Jan. 18, 2022
The formation of carbon-carbon bonds lies at the heart synthetic organic chemistry and is widely applied to construct complex drugs, polymers, materials. Despite its importance, catalytic carbonyl arylation remains comparatively underdeveloped, due limited scope functional group tolerance. Herein we disclose an umpolung strategy achieve radical via dual catalysis. This redox-neutral approach provides a complementary method Grignard-type products from (hetero)aryl bromides aliphatic aldehydes, without need for pre-functionalization. A sequential activation, hydrogen-atom transfer, halogen atom transfer process could directly convert aldehydes corresponding ketyl-type radicals, which further react with aryl-nickel intermediates in overall polarity-reversal process. tolerates─among others─acidic groups, heteroaryl motifs, sterically hindered substrates has been late-stage modification drugs natural products.
Language: Английский
Citations
71
Nature Synthesis, Journal Year: 2022, Volume and Issue: 1(6), P. 464 - 474
Published: June 13, 2022
Language: Английский
Citations
43
Chinese Journal of Chemistry, Journal Year: 2023, Volume and Issue: 41(16), P. 1921 - 1930
Published: April 7, 2023
Comprehensive Summary The radical‐mediated reductive functionalization of aryl halides has been extensively studied. However, the related intermolecular 1,2‐diarylation alkenes, using as radical sources, remains unexplored. Herein, a new electrophotocatalytic alkenes is reported and cyanoaromatics to produce polyarylated alkanes. Using synergistic cathodic reduction visible‐light photoredox catalysis, various electron‐rich electron‐deficient are combined with characterize broad substrate scope, excellent functional group compatibility, selectivity this reaction. Mechanistic investigations reveal that reaction may proceed via process initiated by generation radicals from terminated radical‐radical coupling cyanoaromatic anions.
Language: Английский
Citations
36
ACS Organic & Inorganic Au, Journal Year: 2021, Volume and Issue: 2(2), P. 126 - 147
Published: Dec. 22, 2021
The formation of C(sp3)–C(sp3) and C(sp3)–C(sp2) bonds is one the major research goals synthetic chemists. Electrochemistry commonly considered to be an appealing means drive redox reactions in a safe sustainable fashion has been utilized for C–C bond-forming reactions. Compared anodic oxidative methods, which have extensively explored, cathodic processes are much less investigated, whereas it can pave way alternative retrosynthetic disconnections target molecules discovery new transformations. This review provides overview on recent achievements construction via since 2017. It includes electrochemical reductions convergent paired electrolyses.
Language: Английский
Citations
53
ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(4), P. 2463 - 2471
Published: Feb. 3, 2022
A simple procedure is reported for the nickel-catalyzed defluorinative alkylation of unactivated aliphatic aldehydes. The process involves catalytic reductive union trifluoromethyl alkenes with aldehydes using a nickel complex 6,6'-disubstituted bipyridine ligand zinc metal as terminal reductant. protocol distinguished by its broad substrate scope, mild conditions, and setup. Reaction outcomes are consistent intermediacy an α-silyloxy(alkyl)nickel intermediate generated low-valent catalyst, silyl electrophile, aldehyde substrate. Mechanistic findings cyclopropanecarboxaldehyde provide insights into nature reactive intermediates illustrate fundamental reactivity differences that governed subtle changes in structure.
Language: Английский
Citations
38
Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(34)
Published: July 11, 2022
Herein, we report a reductive cross-coupling reaction of α-oxy halides, simply generated from aldehydes, with series C(sp2 )- and C(sp)-electrophiles. A wide range aryl heteroatom vinyl bromides, alkynyl acyl chlorides react unhindered hindered aldehyde-derived halides by providing protected alcohols as well α-hydroxy ketones. Noteworthy, the couplings are achieved not only through thermal catalysis use metal reductants but also photocatalysis, electrochemistry, mechanochemistry. The unrestricted interchange four strategies indicates their underlying mechanistic similarities. generation NiI intermediate is proposed to be key point for ketyl radical formation via single-electron transfer (SET) event, which was rationalized an array control experiments density functional theory (DFT) calculations.
Language: Английский
Citations
33
Molecules, Journal Year: 2023, Volume and Issue: 28(2), P. 857 - 857
Published: Jan. 15, 2023
Organic electrochemistry has attracted tremendous interest within the novel sustainable methodologies that have not only reduced undesired byproducts, but also utilized cleaner and renewable energy sources. Particularly, oxidative gained major attention. On contrary, reductive electrolysis remains an underexplored research direction. In this context, we discuss advances in transition-metal-free cathodically generated radicals for selective organic transformations since 2016. We highlight electroreductive reaction of alkyl radicals, aryl acyl silyl fluorosulfonyl trifluoromethoxyl radicals.
Language: Английский
Citations
24
Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(18)
Published: Jan. 3, 2023
Alternating current (AC) electrolysis is receiving increased interest as a versatile tool for mild and selective electrochemical transformations. This work demonstrates that AC can enable the concept of stirring-free reactor where periodic switch electrode polarity, inherent to AC, provides uniform across whole volume reactor. Such design implies straightforward approach scaling up electrosynthesis. was demonstrated on range transformations performed in three different RVC-packed reactors 50-mmol scale. Redox-neutral, oxidative, reductive processes were successfully implemented using suggested applicable frequency ranges further investigated types reactions. The advantages AC-enabled - such absence stirring maximized surface area electrodes provide possibility its universal application both small-scale screening experimentation large-scale preparative electrosynthesis without significant optimization needed between.
Language: Английский
Citations
20
Green Chemistry, Journal Year: 2023, Volume and Issue: 25(4), P. 1435 - 1441
Published: Jan. 1, 2023
A phosphine-mediated deoxygenative [3 + 2] cycloaddition reaction for oxazole synthesis via electrochemical anodic oxidation is herein reported.
Language: Английский
Citations
20