The Carbene Chemistry of N-Sulfonyl Hydrazones: The Past, Present, and Future

Chemical Reviews, Год журнала: 2025, Номер unknown

Опубликована: Янв. 10, 2025

N-Sulfonyl hydrazones have been extensively used as operationally safe carbene precursors in modern organic synthesis due to their ready availability, facile functionalization, and environmental benignity. Over the past two decades, there has tremendous progress chemistry of N-sulfonyl presence transition metal catalysts, under metal-free conditions, or using photocatalysts photoirradiation conditions. Many transfer reactions are unique cannot be achieved by any alternative methods. The discovery novel development highly enantioselective new skeletal editing represent notable recent achievements hydrazones. This review describes overall made hydrazones, organized based on reaction types, spotlighting current state-of-the-art remaining challenges addressed future. Special emphasis is devoted identifying, describing, comparing scope limitations methodologies, key mechanistic scenarios, potential applications complex molecules.

Язык: Английский

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Ir‐Catalyzed Enantioselective Synthesis of gem‐Diborylalkenes Enabled by 1,2‐Boron Shift

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(32)

Опубликована: Июнь 15, 2023

Abstract Asymmetric cross‐couplings based on 1,2‐carbon migration from B‐ate complexes have been developed efficiently to access valuable organoboronates. However, enantioselective reactions triggered by 1,2‐boron shift remained be unaddressed synthetic challenge. Here, Ir‐catalyzed asymmetric allylic alkylation enabled was developed. In this reaction, we disclosed that excellent enantioselectivities were achieved through an interesting dynamic kinetic resolution (DKR) process of carbonates at the elevated temperature. Notably, highly (bis‐boryl)alkenes array diversifications versatile molecules. Extensive experimental and computational studies conducted elucidate reaction mechanism DKR clarify origin enantioselectivities.

Язык: Английский

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Asymmetric Synthesis of Chiral 1,2‐Bis(Boronic) Esters Featuring Acyclic, Non‐Adjacent 1,3‐Stereocenters

Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(5)

Опубликована: Дек. 15, 2023

The construction of acyclic, non-adjacent 1,3-stereogenic centers, prevalent motifs in drugs and bioactive molecules, has been a long-standing synthetic challenge due to acyclic nucleophiles being distant from the chiral environment. In this study, we successfully synthesized highly valuable 1,2-bis(boronic) esters featuring nonadjacent 1,3-stereocenters. Notably, reaction selectively produces migratory coupling products rather than alternative deborylative allylation or direct byproducts. This approach introduces new activation mode for selective transformations gem-diborylmethane asymmetric catalysis. Additionally, found that other gem-diborylalkanes, previously challenging steric hindrance, also participated reaction. incorporation 1,2-bis(boryl)alkenes facilitated diversification alkenyl two boron moieties our target compounds, thereby enabling access broad array versatile molecules. DFT calculations were performed elucidate mechanism shed light on factors responsible observed excellent enantioselectivity diastereoselectivity. These determined arise ligand-substrate repulsions syn-addition transition state.

Язык: Английский

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Who is Who in the Carbene Chemistry of N‐Sulfonyl Hydrazones

Chinese Journal of Chemistry, Год журнала: 2024, Номер 42(17), С. 2071 - 2108

Опубликована: Май 27, 2024

Comprehensive Summary Over the past few decades, N ‐sulfonyl hydrazones have been recognized as alternative precursors for hazardous diazo compounds in organic synthesis, allowing diverse innovative and original chemical transformations that were otherwise difficult to achieve. This critical review summarizes major advancements carbene chemistry of hydrazones. The contents this are organized based on research conducted by leading scientists who made significant contributions field. individual transfer reactions their mechanisms, well potential applications synthesis natural products complex bioactive molecules, thoroughly discussed.

Язык: Английский

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Catalytic Selective Functionalization of Poly(organoborons)^†

Chinese Journal of Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Сен. 28, 2024

Comprehensive Summary Organoborons are commonly used building blocks for rapidly increasing molecular complexity. Although significant progress has been made in the selective functionalization of mono‐organoborons, site‐selective poly(organoborons) attracted substantial interest organic synthesis, pharmaceuticals, and agrochemicals due to presence multiple potential reaction sites. This review discusses various activation modes target C–B bond, with diverse transformations being achieved both a efficient manner. Recent advances catalytic 1, n ‐diboronates through ionic radical pathways highlighted. Furthermore, we summarize existing challenges future research directions this field. Key Scientists In 1993, Suzuki, Miyaura coworkers developed pioneering example arylation towards cis‐1,2‐bis(boryl) alkenes, marking inception The Morken group contributions asymmetric diboration alkenes realized elegant these compounds since 2004. 2016, Fernández colleagues internal bond tri(boronates). Since 2019, Aggarwal Giese‐type addition at more substituted 1,2‐bis(boronic) esters photoredox catalysis. controllable regiodivergent alkynylation 1,3‐bis(boronic) was by Gao 2023. Recently, Qin conducted on programmable late‐stage bridge‐substituted bicyclo[1.1.1]pentane (BCP) bis‐boronates. 2013, stereoselective have several groups, including those led Chen. summarizes latest most developments field 1993.

Язык: Английский

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Synthesis of 1,2-Bis- and 1,1,2-Tris-Borylalkanes under Transition Metal-Free and Solvent-Free Conditions

The Journal of Organic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Март 19, 2025

Multi(boronate) esters are useful building blocks in modern chemical synthesis. Herein, we have developed an efficient, transition metal- and solvent-free method for the regioselective boration of alkenes alkynes. The alkali metal Lewis base (NaOMe)-mediated reactions, using bis(pinacolato)diboron (B2pin2) as boron reagent, resulted diboration at room temperature triboration alkynes 60 °C to produce synthetically alkyl 1,2-bis(boronate) 1,1,2-tris(boronate) esters, respectively, excellent yields with high regioselectivity. This environmentally benign protocol demonstrates a broad substrate scope good functional group tolerance gram-scale reaction further highlights practical usefulness method. proposed pathway has been evaluated based on stoichiometric reactions DFT studies.

Язык: Английский

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Transition-Metal-Free Insertion of Diazo Compounds, N-Arylsulfonylhydrazones or Ylides into Organoboronic Acids or Their Derivatives

Synlett, Год журнала: 2023, Номер 34(18), С. 2071 - 2084

Опубликована: Июнь 5, 2023

Abstract Insertion reactions of carbenes or ylides with organoboronic acids their derivatives have emerged as valuable methods for coupling homologation organoboron compounds under metal-free conditions. The crucial steps these are coordination the electron-rich carbon centers carbene precursors to electron-poor boron center, followed by 1,2-migration corresponding tetracoordinated intermediates. This type unique transformation provides an efficient method construction C–C C–X (X = H, B) bonds. Moreover, C–B bonds generated such transformations can be utilized a handle further derivatization iterative homologations. In this Account, we summarize developments in arena according reactive diazo compound, N-arylsulfonylhydrazone ylide species involved. 1 Introduction 2 Reactions Diazo Compounds 3 N-Arylsulfonylhydrazones 4 Ylides 5 Conclusion

Язык: Английский

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Modulation of Lewis Acidity and Steric Parameters in Cyclic Boronates: Copper-Catalyzed Internal-Selective Borylation of Challenging Terminal Alkynes

ACS Catalysis, Год журнала: 2024, Номер 14(17), С. 12694 - 12703

Опубликована: Авг. 8, 2024

The installation of a boron functionality into more substituted carbon terminal alkynes in copper-catalyzed borylations with diborons is still challenging subject, primarily due to the intrinsic Lewis acidity moieties such as B(pin), which typically favor addition carbon. We disclose herein that internal-selective hydroboration variety alkynes, including sterically demanding and electron-rich aryl variants, feasible using commercially available, six-membered bis(hexylene glycolato)diboron [B2(hex)2]. This observation underscores subtle changes boronate-Lewis acidities associated ring size markedly influence regioselectivities borylcupration step. Furthermore, this study reveals reduced steric bulk boronate moieties, well diminished acidities, serve pivotal factors contributing internal selectivity. provides crucial insights regiocontrol alkynes.

Язык: Английский

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Controllable Regiodivergent Alkynylation of 1,3‐Bis(Boronic) Esters Activated by Distinct Organometallic Reagents

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(48)

Опубликована: Окт. 18, 2023

1,3-Bis(boronic) esters can be readily synthesized from alkylBpin precursors. Selective transformations of these compounds hold the potential for late-stage functionalization remaining C-B bond, leading to a diverse array molecules. Currently, there are no strategies available address reactivity and, more importantly, controllable regiodivergent 1,3-bis(boronic) esters. In this study, we have achieved alkynylation The regioselectivity has been clarified based on unique chelation patterns observed with different organometallic reagents. Remarkably, methodology effectively addresses low and bridges gap in radical chemistry, which typically yields only classical products formed via stable intermediates. Furthermore, through approach serve as potent building blocks creating molecular diversity.

Язык: Английский

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Theoretical insight into palladium-catalyzed gem‑difluorovinylation/cyclopropanation of N-methylindole and N-phenylindole with trifluoromethyl diazo compounds

Molecular Catalysis, Год журнала: 2024, Номер 564, С. 114279 - 114279

Опубликована: Июнь 13, 2024

Язык: Английский

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