Electrophilic Sulfur Reagent Design Enables Directed syn-Carbosulfenylation of Unactivated Alkenes

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(16), С. 7189 - 7197

Опубликована: Апрель 18, 2022

A multi-component approach to structurally complex organosulfur products is described via the nickel-catalyzed 1,2-carbosulfenylation of unactivated alkenes with organoboron nucleophiles and tailored electrophiles. The key development this transformation identification a modular N-alkyl-N-(arylsulfenyl)arenesulfonamide family sulfur Tuning electronic steric properties leaving group in these reagents controls pathway selectivity, favoring three-component coupling suppressing side reactions, as examined computational studies. unique syn-stereoselectivity differs from traditional electrophilic sulfenyl transfer processes involving thiiranium ion intermediate arises directed arylnickel(I) migratory insertion mechanism, elucidated through reaction kinetics control experiments. Reactivity regioselectivity are facilitated by collection monodentate, weakly coordinating native directing groups, including sulfonamides, alcohols, amines, amides, azaheterocycles.

Язык: Английский

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Stereocontrolled Synthesis of Fluorinated Isochromans via Iodine(I)/Iodine(III) Catalysis

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(30)

Опубликована: Май 10, 2022

The success of saturated, fluorinated heterocycles in contemporary drug discovery provides a stimulus for creative endeavor main group catalysis. Motivated by the ubiquity isochromans across bioactive small molecule spectrum, prominence anomeric effect regulating conformation, and metabolic lability benzylic position, iodine(I)/iodine(III) catalysis has been leveraged stereocontrolled generation selectively analogs. To augment current arsenal fluorocyclization reactions involving carboxylic acid derivatives, reaction readily accessible 2-vinyl benzaldehydes is disclosed (up to >95 : 05 d.r. 97 03 e.r.). Key stereoelectronic interactions manifest themselves X-ray crystal structures products, thereby validating [CH

Язык: Английский

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Recent Advances in Catalytic Asymmetric Syntheses of Functionalized Heterocycles via Halogenation/Chalcogenation of Carbon‐Carbon Unsaturated Bonds

Advanced Synthesis & Catalysis, Год журнала: 2022, Номер 364(23), С. 3974 - 4005

Опубликована: Окт. 20, 2022

Abstract Halogen (fluorine, chlorine, bromine, iodine) or chalcogen (sulfur, selenium)‐containing heterocycles are widely recognized as key building blocks in many natural products and bioactive targets. Catalytic asymmetric halogenation/chalcogenation of carbon‐carbon unsaturated bonds via onium ion transformations efficient methods to obtain diverse chiral heterocyclic backbones. In the past few years, catalytic enantioselective versions halo/thio/seleno‐functionalizations with various halogen electrophiles have experienced constant development. This review highlights those advances preparing functionalized promoted by organocatalysts metal‐based catalysts. magnified image

Язык: Английский

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Aldehydes as O-Nucleophiles in Cobalt Hydride Hydrogen Atom Transfer Catalysis: Overriding the Innate Somophilicity

Organic Letters, Год журнала: 2023, Номер 25(5), С. 889 - 894

Опубликована: Фев. 1, 2023

In metal hydride-catalyzed alkene hydrofunctionalization reactions via hydrogen atom transfer, simple carbonyl groups have been well-recognized as good somophiles at the carbon for C-C bond formation. Here we report an alternative pathway exploring O-nucleophile to make new C-O bonds during CoH-catalyzed oxidative cyclization of alkenyl aldehydes. This reaction provides a rapid, mild, modular, and stereoselective (up >20:1) entry saturated O-heterocycles nucleophilic trapping in situ-formed oxocarbenium intermediate. The key overriding carbonyl's innate somophilicity was found be promoting formation organocobalt species suppressing radical exchange.

Язык: Английский

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Enantioselective Synthesis of γ-Lactams by Lewis Base Catalyzed Sulfenoamidation of Alkenes

Organic Letters, Год журнала: 2019, Номер 22(7), С. 2501 - 2505

Опубликована: Дек. 20, 2019

A method for the catalytic, enantioselective, intramolecular 1,2-sulfenoamidation of alkenes is described. Lewis base activation a suitable sulfur electrophile generates an enantioenriched, thiiranium ion intermediate from β,γ-unsaturated sulfonyl carboxamide. This subsequently intercepted by sulfonamide nitrogen resulting in cyclization to form γ-lactams. Electron-poor required use new selenophosphoramidate catalyst. Subsequent manipulations products harness latent reactivity both amide and thioether functionality.

Язык: Английский

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Lewis Base/Brønsted Acid Co‐Catalyzed Asymmetric Thiolation of Alkenes with Acid‐Controlled Divergent Regioselectivity

Chemistry - A European Journal, Год журнала: 2019, Номер 25(67), С. 15411 - 15418

Опубликована: Сен. 6, 2019

Abstract A divergent strategy for the facile preparation of various enantioenriched phenylthio‐substituted lactones was developed based on Lewis base/Brønsted acid co‐catalyzed thiolation homoallylic acids. The acid‐controlled regiodivergent cyclization (6‐ endo vs. 5‐ exo ) and acid‐mediated stereoselective rearrangement were explored. Experimental computational studies performed to clarify origins regioselectivity enantioselectivity. calculation results suggest that C−O C−S bond formation might occur simultaneously, without a commonly supposed catalyst‐coordinated thiiranium ion intermediate potential π–π stacking between substrate SPh as an important factor in enantio‐determining step. Finally, this methodology applied rapid syntheses bioactive natural products (+)‐ricciocarpin ( R )‐dodecan‐4‐olide.

Язык: Английский

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Catalytic Access to Functionalized Allylic gem‐Difluorides via Fluorinative Meyer–Schuster‐Like Rearrangement

Angewandte Chemie International Edition, Год журнала: 2020, Номер 59(27), С. 11010 - 11019

Опубликована: Апрель 14, 2020

Abstract An unprecedented approach for efficient synthesis of functionalized allylic gem‐difluorides via catalytic fluorinative Meyer–Schuster‐like rearrangement is disclosed. This transformation proceeded with readily accessible propargylic fluorides, and low‐cost B–F reagents electrophilic by sulfide catalysis. A series iodinated, brominated, trifluoromethylthiolated that were difficult to access other methods facilely produced a wide range functional groups. Importantly, the obtained iodinated products could be incorporated into different drugs natural products, expediently converted many valuable gem‐difluoroalkyl molecules as well. Mechanistic studies revealed this reaction went through regioselective fluorination alkynes followed formal 1,3‐fluorine migration under assistance give desired products.

Язык: Английский

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Chiral Bifunctional Selenide Catalysts for Asymmetric Bromolactonization

Asian Journal of Organic Chemistry, Год журнала: 2019, Номер 9(2), С. 192 - 196

Опубликована: Дек. 27, 2019

Abstract The development of chiral selenium catalysts for asymmetric transformations has become a pre‐eminent topic in the field organocatalytic chemistry. Herein, we report bifunctional selenide bearing hydroxy group and discuss their application to bromolactonization reactions. importance design enantioselective bromolactonizations was clearly demonstrated present work.

Язык: Английский

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Chalcogenide-Catalyzed Intermolecular Electrophilic Thio- and Halofunctionalization of gem-Difluoroalkenes: Construction of Diverse Difluoroalkyl Sulfides and Halides

Organic Letters, Год журнала: 2020, Номер 22(19), С. 7581 - 7587

Опубликована: Сен. 23, 2020

Thio- and halodifluoromethylated compounds are an important class of in medicinal chemistry organic synthesis. Herein, we report a facile method for the construction these via chalcogenide-catalyzed intermolecular electrophilic thio- halofunctionalization gem-difluoroalkenes. Simple treatment gem-difluoroalkenes with sulfur/halogen reagents various O- or N-nucleophiles affords diverse multifunctionalized compounds. This reaction features relatively broad substrate scope, good functional group tolerance, mild conditions.

Язык: Английский

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Enantioselective Inter- and Intramolecular Sulfenofunctionalization of Unactivated Cyclic and (Z)-Alkenes

ACS Catalysis, Год журнала: 2022, Номер 12(12), С. 7377 - 7385

Опубликована: Июнь 7, 2022

A method for the enantioselective, Lewis base-catalyzed sulfenofunctionalization of cyclic and (Z)-alkenes is reported. The intermediate thiiranium ion generated in presence a selenophosphoramide catalyst intercepted by variety nucleophiles. diverse array inter- intramolecular functionalizations proceed high yield good to enantioselectivity (86:14-98:2 er). Prior experimental computational studies indicated such enantiotopic face discrimination be poor; however, results disclosed herein remediate previous findings. Control experiments were performed investigate different behavior their more established (E)-counterparts.

Язык: Английский

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