Cross-Electrophile Couplings of Activated and Sterically Hindered Halides and Alcohol Derivatives

Accounts of Chemical Research, Journal Year: 2020, Volume and Issue: 53(9), P. 1833 - 1845

Published: Aug. 25, 2020

ConspectusTransition metal catalyzed cross-electrophile coupling of alkyl electrophiles has evolved into a privileged strategy that permits the facile construction valuable C(sp3)–C bonds. Numerous elegant Ni-catalyzed methods, for example, arylation, allylation, acylation, and vinylation primary secondary halides have been developed. This prior work provided important mechanistic insights selectivity reactivity partners, which are largely dictated by both catalysts reactants. In spite advances made to date, number challenging issues remain, including (1) achieving stereoselective syntheses C–C bonds rely primarily on functionalized or activated precursors, (2) diversifying electrophiles, (3) gaining underlying reaction mechanisms.In this Account, we summarize Ni- Fe-catalyzed reductive bond forming methods developed in our laboratory, allowed us couple activated, sterically hindered tertiary C(sp3)–O access methylated trifluoromethylated products, esters, C-glycosides, quaternary carbon centers. We will begin with brief discussion chemoselective unactivated alkyl–alkyl bonds, focus effects ligands reductants, along leaving group-directed reactivities halides, role they play promoting methyl, trifluoromethyl, glycosyl chloroformates. Matching these suitable partners is considered essential success; something can be tuned means appropriate Ni catalysts. Second, detail how tuning steric electronic nickel labile pyridine-type additives (primarily MgCl2) effective creation arylated all-carbon centers through aryl encumbered halides. contrast, use bulkier bipyridine terpyridine incorporation relative small-sized acyl allyl groups acylated allylated Finally, show knowledge gained halide enabled develop permit oxalates allyl, aryl, vinyl wherein Barton C–O radical fragmentation mediated Zn MgCl2 promoted The same protocol applicable arylation derived from α-hydroxyl carbonyl substrates, involves formation relatively stable α-carbonyl centered radicals. Thus, Account not only summarizes synthetic allow using but also provides insight relationship between structure substrates catalysts, as well additives.

Language: Английский

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Ni-electrocatalytic Csp3–Csp3 doubly decarboxylative coupling

Nature, Journal Year: 2022, Volume and Issue: 606(7913), P. 313 - 318

Published: April 5, 2022

Language: Английский

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Nickel-Catalyzed Reductive Cross-Couplings: New Opportunities for Carbon–Carbon Bond Formations through Photochemistry and Electrochemistry

CCS Chemistry, Journal Year: 2021, Volume and Issue: 4(1), P. 9 - 30

Published: Oct. 15, 2021

Open AccessCCS ChemistryMINI REVIEW1 Jan 2022Nickel-Catalyzed Reductive Cross-Couplings: New Opportunities for Carbon–Carbon Bond Formations through Photochemistry and Electrochemistry Liang Yi†, Tengfei Ji†, Kun-Quan Chen, Xiang-Yu Chen Magnus Rueping Yi† Institute of Organic Chemistry, RWTH Aachen University, 52074 †L. Yi T. Ji contributed equally to this work.Google Scholar More articles by author , Ji† School Chemical Sciences, University the Chinese Academy Beijing 100049 Google *Corresponding authors: E-mail Address: [email protected] King Abdullah Science Technology (KAUST), Thuwal 23955 https://doi.org/10.31635/ccschem.021.202101196 SectionsAboutAbstractPDF ToolsAdd favoritesDownload CitationsTrack Citations ShareFacebookTwitterLinked InEmail Metal-catalyzed cross-electrophile couplings have become a valuable tool carbon–carbon bond formation. This minireview provides comprehensive overview recent developments in topical field couplings, explanations current state-of-the-art, highlights new opportunities arising emerging fields photoredox catalysis electrochemistry. Download figure PowerPoint Introduction Carbon–carbon formations always been one most useful reactions both industry academia gained considerable attention from many synthetic chemists who developed novel strategies achieve improved sustainable transformations. Transition metal has continually provided activation modes C–C formations1–5 fascinated long time. Many named associated with transition powerful method cross-couplings electrophiles organometallic nucleophiles (Scheme 1a). Despite progress, use reagents can cause undesired side chemical wastes. Alternatively, cross-nucleophile coupling as an efficient synthesis synthetically biologically important compounds 1b).6–8 However, lower availability carbon represents limitation. Recently, metal-catalyzed cross-coupling between two bench stable under reductive conditions emerged construction bonds. In particular, nickel (Ni) catalysts, characterized low reduction potential electronegativity, undergo rapid oxidative addition.9 As such, it is not surprising that nickel-catalyzed flourishing area organic chemistry characteristic advantages over classical synthesis, such widely available avoiding unstable time-consuming costly prefunctional processes. Scheme 1 | (a–c) cross-coupling. Thus, there significant progress development constructing The first example was published about 100 years ago Wurtz10 Tollens Fittig11 using sodium reductant mediator aryl halides alkyl halides. Stoichiometric high temperatures are needed. Therefore, functional group tolerance application limited. Another strategy electrosynthesis. Early explorations electroreductive include cross/homo-coupling halides, acyl, carboxylation cross-couplings.12 be difficult specialized laboratory equipment required. These limitations restricted further formation bonds several years. electrosynthesis recently seen renaissance cross-couplings. popular combination metallic reducing agents number Mn or Zn reductants.13–20 its success, addition scalability efficiency problems, utility powders inevitably produces excess waste. photochemical alternatives developed. impressive achievements made merging photo- electrochemistry create avoid powders. Considering construction, provide conceptual understanding 1c). Against background, we attempt give state-of-the-art highlight pathways. Alkyl–Aryl Cross-Coupling Nickel/metallic agent system viability alkyl-aryl via initially demonstrated research groups Durandetti,21 Lipshutz,22 Wangelin23 2). Specifically, Durandetti co-workers21 described α-chloroesters, well Refortmatsky reaction presence manganese metal. Lipshutz co-workers22 investigated participation zinc palladium-catalyzed halide bromide, Wangelin co-workers23 reported cobalt-catalyzed early examples combined metal/reducing systems construct milder conditions. 2 reporting catalysis. recently, more recognized general concept actively researched exciting 2010, Weix co-workers24 Ni/Mn selective equimolar quantities halide. High cross-selectivities were achieved bipyridyl phosphine ligand 3a). 3 Overview alkyl–aryl protocol, stoichiometric required, broad range tolerated. drawback, secondary bromides resulted mixed isomer products. Nevertheless, direct without intermediate organomanganese species protocol. Regarding mechanism 3b), postulated key step valent Ni(0) generates Ar–Ni(II) I. Subsequent radical affords Ar–Ni(III)–R II. Finally, elimination II desired product Ni(I) III, which could produce single-electron transfer (SET) halogen-atom abstraction. Reduction III finishes catalytic cycle. Concurrently, similar results cobalt/phosphine disclosed Amatore Gosmini25 electron-deficient bromides. After these studies, great efforts focused on different 3c).26–38 Notably, Molander co-workers39,40 successfully expanded installation fragments onto pharmaceutically relevant heterocyclic motifs. A variety aliphatic tosylates underwent moderate good yields, furnishing substituted heteroaromatic compounds. achievements, alkylamines, abundant natural feedstocks, had realized until recently. 2017, Watson co-workers41 Suzuki–Miyaura boronic acids, employing Katritzky salts C-centered-radical precursors. Very Rueping,42 Watson,43 Martin,44 Han45 independently applied cases, employed optimal reductants elevated usually Han’s Ni/Zn enabled wider substrate scope including bromoalkynes Although primary developed, tertiary easy due dominant β-hydride reaction. 2015, Gong co-workers46 resolved issue pyridine (Py) 4-(N,N-dimethylamino)pyridine (DMAP) carbene salt additives suppress enhance 4). tolerated various better obtained electron-withdrawing substituents. 4 Until now, cases form at ipso-carbon where regioselectivity less explored 5a). An migratory Zhu co-workers47 2017 5b). proceeded smoothly Ni(ClO4)2(H2O)6/6,6′-dimethyl-2,2′-bipyridyl catalyst nonactivated affording 1,1-diarylalkane derivatives, widespread products active molecules, excellent yields regioselectivity. 5 Nickel-catalyzed proposed transformation 5c. Initially, inactivated bromide leads Ni(II) complex following insertion steps deliver thermodynamically benzylic-Ni(I) III. Then, Ni(III) IV. Ni(I)-X V. then reduced powder close class also Yin co-workers,48 NiI2/bathocuproine reductant. Interestingly, opposite proposed. step, rather than I′. chain process II′ generated SET Ni(I)−X ( IV′). Several control experiments trapping carried out support their mechanism. electrophiles, types cross-couplings, enable modes, still highly desirable. During last few years, metal/photoredox dual witnessed remarkable offered unconventional transformations.49–65 To date, strongly dominated redox neutral pathway, wherein nucleophile partner changes oxidation state nickel/photoredox offers alternative absence 6). 6 representation pathway Nickel-photoredox 2016, MacMillan co-workers66–68 catalyzed 7a). Ni/photoredox mechanism, Concomitantly, hydrogen-atom abstraction tris(trimethylsilyl)silane (TTMSS) bromine radicals forms stabilized silyl intermediate. mediated radical, binds I, leading photo Ir(II). case, photoexcited generate radical. 7 (a–d) Lei co-workers,69 studies MacMillan, Et3N terminal 7b. complex. At same time, low-valent resulting intercepted species. species, Ir(II) cycles. used Vannucci co-workers,70 triethanolamine Based previous developments, Jensen co-workers71 continuously stirred-tank reactor platform flow. gram-scale after 13 h, opened up applications system. related approach Brill co-workers72 assembly drug-like benzylic chlorides (hetero)aryl continuous flow highlighting industrial applicability. Furthermore, co-workers73 bathocuproine 7c). Compared iodides, simple abundant, inexpensive, readily methods. they electrophilic partners nucleophilic aromatic substitutions. chlorides. involving substrates, aminosilane reductant, NiCl2(bim) Ir-based photocatalyst, afforded C(sp2)−C(sp3) coupled generally 7d).74 context series salts, aziridines, epoxides. co-workers,75 identified C(sp3) 4CzIPN photocatalyst NiBr2(DME)/4,4′-di-tert-butylbipyridine (dtbbpy) catalyst, differently substrates 8a). 8 (a–f) Doyle co-workers32 nickel/Mn-catalyzed styrenyl aziridines iodides. drawback aziridine did work 8b). study co-workers76 constituted strategy. Their way newly showed scope. iodides NiBr2(DME)/dtbbpy catalyst. able cyclic classic methods, 8c). 8d. iodide β-iodoamine IV formed ring-opening aziridine. Subsequently, 4CzIPN−• Ni(I)−I III). I Then [4-CzIPN]−• nickel/Mn gave MnI2 instead β-iodoamine; thus, no obtained. Continued co-workers77 epoxides 8e). Ni/Ti/photoredox Various styrene oxides, epoxides, all reacted regioselectivities. Allylic carbonates proven suitable cross-couplings.78–80 nice Chu co-workers81 allylic vinyl triflates 8f). E- Z-configured 1,4-dienes choice photocatalysts. When Ir(ppy)2(dtbbpy)+ photoinduced contra-thermodynamic E→Z isomerization would occur (Z)-1,4-diene product.81 strategies, them rely potentials photocatalysts furnish addition, appealing when considering toxicity cost photoactive electron-donor-acceptor (EDA) allows generation mild based-photocatalysts dyes. strategy, co-workers82 EDA N-hydroxyphthalimide (NHPI) esters. proceeds NHPI ester Hantzsch (HE), upon radiation-induced (eq 1).82 Electrochemical may offer economical Recent ability bond-forming reactions. Within area, electrochemically induced integrating 9). seminal chloroesters electrochemical strategy.12 breakthrough very Hansen co-workers83 10a). sacrificial anode tuning found crucial cooperative circumvented need temperatures. exhibited generality. 9 10 aryl–alkyl Further Bio co-workers84 Hansen’s method, esters source amine divided cell 10b). Later, one-pot C(sp2)–C(sp3) Loren co-workers85 10c), redox-active situ carboxylates tetramethyluronium hexafluorophosphate. Sevov co-workers86 shuttles protect reduction, thus improving suppressing side-product 10d). across wide aryl, heteroaryl, Given importance concurrently, Rueping87 Mei88 11a). Both methods scope, giving rise corresponding derivatives yields. experimental density theory (DFT) co-workers87 plausible 11b). 11 (a b) cathode surface. gives Ar−Ni(I) occurs Ar−Ni(II)−Br cathodic will benzylic-Ni(II) release regenerate Ni(0). Aryl–Aryl Cross-Couplings comparison bonds, C(sp2)–C(sp2) challenging result subtle difference electrophiles. 2008, Gosmini89 unsymmetrical biaryl success reactivity profiles allowed extended 2-halopyridine group.90 co-workers91 selectivities controlled catalysts electronic properties reports 12a). Mechanistically, react exclusively Pd(0) Pd(II) transmetalation complex, Ar1–Pd(II)–Ar2 IV, asymmetrical biaryls. additive potassium fluoride (KF) achieving selectivity, presumably selectivity palladium triflate bromide. Olivares Weix92 other triflates, triflates,93 tosylates,94 ortho-fluoro-substituted amides,95 difluoromethyl 2-pyridyl sulfone,96 bromides, 2,2-difluorovinyl tosylate.97 12 aryl–aryl co-workers98 polyfluorinated arenes 12b). protocol opens entry multifluorinated starts generating [C5F5N]•− C5F5N, trapped II′. III′, Also, Ni(0)/Ni(I)/Ni(III)/Ni(I) cycle possible, involves Ni(I)–C5F4N IV′) Besides aryl-heteroarybond regard, Léonel co-workers99–102 heteroaryls, 3-chloro-6-methoxypyridazines, 3-amino-6-chloropyridazines, chloropyrimidines 12c). Alkyl–Alkyl discussed above,

Language: Английский

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Controlling Ni redox states by dynamic ligand exchange for electroreductive Csp3–Csp2 coupling

Science, Journal Year: 2022, Volume and Issue: 376(6591), P. 410 - 416

Published: April 21, 2022

Cross-electrophile coupling (XEC) reactions of aryl and alkyl electrophiles are appealing but limited to specific substrate classes. Here, we report electroreductive XEC previously incompatible including tertiary bromides, chlorides, aryl/vinyl triflates. Reactions rely on the merger an electrochemically active complex that selectively reacts with bromides through 1e

Language: Английский

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Site-Selective C–H alkylation of Complex Arenes by a Two-Step Aryl Thianthrenation-Reductive Alkylation Sequence

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(21), P. 7909 - 7914

Published: May 24, 2021

Herein, we present an undirected para-selective two-step C–H alkylation of complex arenes useful for late-stage functionalization. The combination a site-selective thianthrenation with palladium-catalyzed reductive electrophile cross-coupling grants access to diverse range synthetically alkylated which cannot be accessed otherwise comparable selectivity, diversity, and practicality. robustness this transformation is further demonstrated by thianthrenium-based coupling two fragments.

Language: Английский

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Desulfonylative Transformations of Sulfones by Transition-Metal Catalysis, Photocatalysis, and Organocatalysis

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(5), P. 3013 - 3032

Published: Feb. 18, 2022

Sulfones are common, readily available reagents that have recently attracted attention as versatile for cross-coupling reactions. This Review summarizes advances in desulfonylative transformations of sulfones affected by molecular catalysis, including transition-metal catalysts, photocatalysts, and organocatalysts. In addition to catalyst choice, the design sulfonyl group is a critical factor control reactivity. The concepts presented herein will provide new strategies construct diverse molecules with high efficiency modularity.

Language: Английский

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Electroreductive Cross‐Electrophile Coupling (eXEC) Reactions

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(45)

Published: June 16, 2023

Abstract Electrochemistry utilizes electrons as a potent, controllable, and traceless alternative to chemical oxidants or reductants, typically offers more sustainable option for achieving selective organic synthesis. Recently, the merger of electrochemistry with readily available electrophiles has been recognized viable increasingly popular methodology efficiently constructing challenging C−C C‐heteroatom bonds in manner complex molecules. In this mini‐review, we have systematically summarized most recent advances electroreductive cross‐electrophile coupling (eXEC) reactions during last decade. Our focus on electrophiles, including aryl alkyl (pseudo)halides, well small molecules such CO 2 , SO D O.

Language: Английский

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Iron-catalysed reductive cross-coupling of glycosyl radicals for the stereoselective synthesis of C-glycosides

Nature Synthesis, Journal Year: 2022, Volume and Issue: 1(3), P. 235 - 244

Published: Feb. 17, 2022

Language: Английский

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Diversifying Amino Acids and Peptides via Deaminative Reductive Cross-Couplings Leveraging High-Throughput Experimentation

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(10), P. 5684 - 5695

Published: Feb. 28, 2023

A deaminative reductive coupling of amino acid pyridinium salts with aryl bromides has been developed to enable efficient synthesis noncanonical acids and diversification peptides. This method transforms natural, commercially available lysine, ornithine, diaminobutanoic acid, diaminopropanoic alanines homologated derivatives varying chain lengths. Attractive features include ability transverse scales, tolerance pharma-relevant (hetero)aryls biorthogonal functional groups, the applicability beyond monomeric short macrocyclic peptide substrates. The success this work relied on high-throughput experimentation identify complementary reaction conditions that proved critical for achieving a broad scope range substrates including

Language: Английский

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Overview of Recent Scale-Ups in Organic Electrosynthesis (2000–2023)

Organic Process Research & Development, Journal Year: 2024, Volume and Issue: 28(2), P. 338 - 366

Published: Jan. 18, 2024

This review summarizes examples of organic electrosynthesis from the peer-reviewed literature 2000 to 2023 that have been conducted on scales 20 g or above. A significant portion these were a ≤100 scale, while detailed reports kilogram-scale remain scarce in pharmaceutical industry. In addition chemical transformation, this also highlights type reactor used and projected productivity metric as ways compare different reports. The selected scale-ups described herein illustrate remaining challenges currently preventing routine use large-scale

Language: Английский

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