The Persistent Radical Effect in Organic Synthesis

Angewandte Chemie International Edition, Год журнала: 2019, Номер 59(1), С. 74 - 108

Опубликована: Май 22, 2019

Abstract Radical–radical couplings are mostly nearly diffusion‐controlled processes. Therefore, the selective cross‐coupling of two different radicals is challenging and not a synthetically valuable transformation. However, if have lifetimes they generated at equal rates, will become dominant process. This high cross‐selectivity based on kinetic phenomenon called persistent radical effect (PRE). In this Review, an explanation PRE supported by simulations simple model systems provided. Radical stabilities discussed within context their lifetimes, various examples PRE‐mediated radical–radical in synthesis summarized. It shown that restricted to coupling with transient radical. If one partner longer‐lived than other radical, operates achieved. important point expands scope chemistry. The Review divided into parts, namely 1) or organic 2) “radical–metal crossover reactions”; here, metal‐centered species more generally transition‐metal complexes able react discussed—a field has flourished recently.

Язык: Английский

---

Nickel-Catalyzed Reductive Dicarbofunctionalization of Alkenes

Journal of the American Chemical Society, Год журнала: 2017, Номер 139(20), С. 6835 - 6838

Опубликована: Май 10, 2017

An intermolecular, three-component reductive dicarbofunctionalization of alkenes is presented here. The combination Ni catalysis with TDAE as final reductant enables the direct formation Csp3–Csp3 and Csp3–Csp2 bonds across a variety π-systems using two different electrophiles that are sequentially activated exquisite selectivity under mild reaction conditions.

Язык: Английский

---

Tandem Difluoroalkylation‐Arylation of Enamides Catalyzed by Nickel

Angewandte Chemie International Edition, Год журнала: 2016, Номер 55(40), С. 12270 - 12274

Опубликована: Сен. 8, 2016

Abstract A nickel‐catalyzed three‐component reaction for the synthesis of difluoroalkylated compounds through tandem difluoroalkylation‐arylation enamides has been developed. The tolerates a variety arylboronic acids and widely available difluoroalkyl bromides, even relatively inert substrate chlorodifluoroacetate. significant advantages this protocol are low‐cost nickel catalyst, synthetic convenience, excellent functional‐group compatibility high efficiency.

Язык: Английский

---

Nickel-catalyzed difunctionalization of allyl moieties using organoboronic acids and halides with divergent regioselectivities

Chemical Science, Год журнала: 2017, Номер 9(3), С. 600 - 607

Опубликована: Окт. 26, 2017

We present herein a nickel-catalyzed dicarbofunctionalization of alkenes using readily available organoboronic acids and organic halides in three-component fashion.

Язык: Английский

---

Visible Light‐Induced Room‐Temperature Heck Reaction of Functionalized Alkyl Halides with Vinyl Arenes/Heteroarenes

Angewandte Chemie International Edition, Год журнала: 2017, Номер 56(45), С. 14212 - 14216

Опубликована: Сен. 22, 2017

The first visible light-induced Pd-catalyzed Heck reaction of α-heteroatom substituted alkyl iodides and -bromides with vinyl arenes/heteroarenes has been developed. This transformation efficiently proceeds at room temperature enables synthesis valuable functionalized allylic systems, such as silanes, boronates, germanes, stannanes, pivalates, phosphonates, phthalimides, tosylates from the corresponding α-substituted methyl iodides. Notably, latter substrates failed under existing thermally induced conditions, which highlights importance light for this transformation.

Язык: Английский

---

Enantioselective Nickel-Catalyzed anti-Carbometallative Cyclizations of Alkynyl Electrophiles Enabled by Reversible Alkenylnickel E/Z Isomerization

Journal of the American Chemical Society, Год журнала: 2016, Номер 138(26), С. 8068 - 8071

Опубликована: Июнь 22, 2016

Nickel-catalyzed additions of arylboronic acids to alkynes, followed by enantioselective cyclizations the alkenylnickel species onto tethered ketones or enones, are reported. These reactions reliant upon formal anti-carbonickelation alkyne, which is postulated occur reversible E/Z isomerization an species.

Язык: Английский

---

Copper-Catalyzed Radical 1,4-Difunctionalization of 1,3-Enynes with Alkyl Diacyl Peroxides and N-Fluorobenzenesulfonimide

Journal of the American Chemical Society, Год журнала: 2018, Номер 141(1), С. 548 - 559

Опубликована: Дек. 4, 2018

Many reactions involving allenyl ion species have been studied, but radicals are less well understood, perhaps because of the inconvenience associated with generation short-lived radicals. We describe here a versatile method for and their previously unreported applications in intermolecular 1,4-carbocyanation 1,4-sulfimidocyanation 1,3-enynes. With assistance trifunctional reagents, alkyl diacyl peroxides or N-fluorobenzenesulfonimide, range synthetically challenging multisubstituted allenes can be prepared high regioselectivity. These easily transformed into useful structures such as fluorinated vinyl cyanides, lactones, functionalized amides, 1-aminonaphthalenes, pyridin-2(1H)-ones, several novel transformations reported. The results radical scavenger clock experiments consistent proposed pathway. Density functional theory (DFT) IR spectroscopy studies suggest formation an isocyanocopper(II) ligand exchange step. On basis IR, DFT, diastereoselectivity studies, isocyanocopper(II)/copper(I) catalytic cycle is proposed, which differs from considered Cu(III) mechanism cyanation reactions.

Язык: Английский

---

Fluoroalkylation reactions in aqueous media: a review

Green Chemistry, Год журнала: 2018, Номер 20(8), С. 1662 - 1731

Опубликована: Янв. 1, 2018

Recent advances in aqueous fluoroalkylation using various reagents are summarized this review.

Язык: Английский

---

Dual Photoredox/Nickel‐Catalyzed Three‐Component Carbofunctionalization of Alkenes

Angewandte Chemie International Edition, Год журнала: 2019, Номер 58(35), С. 12286 - 12290

Опубликована: Июнь 26, 2019

Abstract The potential of merging photoredox and nickel catalysis to perform multicomponent alkene difunctionalizations under visible‐light irradiation is demonstrated here. Secondary tertiary alkyl groups, as well sulfonyl moieties can be added the terminal position double bond with simultaneous arylation internal carbon atom in a single step mild reaction conditions. process, devoid stoichiometric additives, benefits from use bench‐stable easy‐to‐handle reagents, operationally simple, tolerates wide variety functional groups.

Язык: Английский

---

A multicomponent synthesis of stereodefined olefins via nickel catalysis and single electron/triplet energy transfer

Nature Catalysis, Год журнала: 2019, Номер 2(8), С. 678 - 687

Опубликована: Июль 8, 2019

Язык: Английский

---