Recent advances in iridium-catalyzed enantioselective allylic substitution using phosphoramidite-alkene ligands

Catalysis Science & Technology, Год журнала: 2022, Номер 12(13), С. 4100 - 4112

Опубликована: Янв. 1, 2022

This minireview describes the recent progress of iridium-catalyzed enantioselective allylic substitution using phosphoramidite-alkene ligands realizing highly carbon–carbon and carbon–heteroatom bond formation.

Язык: Английский

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Modularity in the C_sp3 Space─Alkyl Germanes as Orthogonal Molecular Handles for Chemoselective Diversification

ACS Catalysis, Год журнала: 2022, Номер 12(9), С. 4833 - 4839

Опубликована: Апрель 8, 2022

To meet the need for a rapid, streamlined, and potentially automatable molecule synthesis, modular coupling approaches are highly desired. While diversification of aromatic molecules, i.e., Csp2 space, has greatly advanced, syntheses in Csp3 space comparably much less developed. This report explores potential alternative functional handles, alkyl germanes, this context, which combine features stability synthesizability with selective reactivity. We show chemoselective functionalization germanes (R-GeEt3) under photoredox conditions (Giese addition) implementation building block, allows Csp3-halogen vs Csp3-Bpin Csp3-GeEt3 sites.

Язык: Английский

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Diborylmethyl Group as a Transformable Building Block for the Diversification of Nitrogen‐Containing Molecules

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(37)

Опубликована: Июль 18, 2022

Abstract The development of new approaches to installing diverse carbon fragments a nitrogen atom has attracted considerable attention in chemical science. While numerous strategies have been devised forge C(sp 3 )−N bonds, one conceptually powerful and straightforward approach is insert transformable sp ‐carbon unit onto for modular diversification. Here we describe the successful synthesis halo‐diborylmethanes their applications preparation nitrogen‐substituted diborylmethanes through homologative coupling with variety nucleophiles including biologically relevant molecules. This process exhibits remarkably broad substrate scope, usefulness obtained compounds demonstrated by diversification diborylmethyl group access various nitrogen‐containing

Язык: Английский

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Electrooxidative Activation of B−B Bond in B₂cat₂: Access to gem‐Diborylalkanes via Paired Electrolysis

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(14)

Опубликована: Фев. 1, 2023

This report describes the unprecedented electrooxidation of a solvent (e.g., DMF)-ligated B2 cat2 complex, whereby solvent-stabilized boryl radical is formed via quasi-homolytic cleavage B-B bond in DMF-ligated cation. Cyclic voltammetry and density functional theory provide evidence to support this novel activation strategy. Furthermore, strategy for electrochemical gem-diborylation gem-bromides paired electrolysis developed first time, affording range versatile gem-diborylalkanes, which are widely used synthetic society. Notably, reaction approach scalable, transition-metal-free, requires no external activator.

Язык: Английский

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Facile Access to Cyclopropylboronates via Stereospecific Deborylative Cyclization: A Leaving Group‐Assisted Activation of Geminal Diborons

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(21)

Опубликована: Март 24, 2023

Herein we reported a transition metal-free deborylative cyclization strategy, based on which two routes have been developed, generating racemic and enantioenriched cyclopropylboronates. The of geminal-bis(boronates) bearing leaving group was highly diastereoselective, tolerating few functional groups applicable to heterocycles. When optically active epoxides were used as the starting materials, cyclopropylboronates could be efficiently prepared with >99 % stereospecificity. Mechanistic studies showed that at γ-position played crucial role significantly promoted activation gem-diboron moiety.

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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Diborodichloromethane as Versatile Reagent for Chemodivergent Synthesis of gem‐Diborylalkanes

Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(3)

Опубликована: Дек. 8, 2023

Abstract The development of boron reagents is crucial for synthetic chemistry. Herein, we present a scalable and practical synthesis diborodichloromethane (DBDCM) through the reaction trichloromethyllithium with bis(pinacolato)diboron (B 2 pin ). resulting DBDCM reagent serves as basic unit construction various structurally diverse gem ‐diborylalkanes controllable C−Cl functionalizations. Moreover, have developed consecutive tetra‐functionalizations tertiary quaternary carbon containing molecules. use isotopically enriched 13 C‐chloroform 10 B enables C‐DBDCM B‐DBDCM reagents, which are beneficial convenient carbon‐13 boron‐10

Язык: Английский

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Ir-Catalyzed Regioselective Dihydroboration of Thioalkynes toward Gem-Diboryl Thioethers

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(4), С. 2305 - 2314

Опубликована: Янв. 19, 2023

While 1,1-diboryl (gem-diboryl) compounds are valuable synthetic building blocks, currently, related studies have mainly focused on those alkanes without a hetero functional group in the α-position. gem-Diboryl with an α-hetero substituent, though highly versatile, been limitedly accessible and thus rarely utilized. Herein, we developed first α-dihydroboration of heteroalkynes leading to efficient construction gem-diboryl, hetero-, tetra-substituted carbon centers. This straightforward, practical, mild, atom-economic reaction is attractive complement conventional multistep strategy relying deprotonation gem-diborylmethane by strong base. Specifically, [Ir(cod)(OMe)]2 was found be uniquely effective for this process thioalkynes, excellent α-regioselectivity when delivering two boryl groups, which remarkable view many competitive paths including monohydroboration, 1,2-dihydroboration, dehydrodiboration, triboration, tetraboration, etc. Control experiments combined DFT calculations suggested that involves sequential hydroboration events. The second requires higher energy barrier due severe steric repulsion generating congested α-sulfenyl gem-diboryl center, structural motif almost unknown before.

Язык: Английский

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A Novel Synthesis of Halogenated gem-Diboron Reagents

Chinese Journal of Organic Chemistry, Год журнала: 2023, Номер 43(2), С. 777 - 777

Опубликована: Янв. 1, 2023

A novel synthesis of halogenated gem-diboronates (X-CR(Bpin)2) was developed.The reagents are stable and easy to prepare in a large scale.Tetra-substituted can be prepared high yields when using alkylsubstituted gem-dihalides, providing new strategy for the gem-diboron compounds.

Язык: Английский

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Palladium‐Catalyzed Cascade Heck Coupling and Allylboration of Iododiboron Compounds via Diboryl Radicals

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(18)

Опубликована: Март 6, 2024

Geminal bis(boronates) are versatile synthetic building blocks in organic chemistry. The fact that they predominantly serve as nucleophiles the previous reports, however, has restrained their potential. Herein we disclose ambiphilic reactivity of α-halogenated geminal bis(boronates), which first catalytic utilization was accomplished by merging a formal Heck cross-coupling with highly diastereoselective allylboration aldehydes or imines, providing new avenue for rapid assembly polyfunctionalized boron-containing compounds. We demonstrated this cascade reaction is efficient and compatible various functional groups, wide range heterocycles. In contrast to classical Pd(0/II) scenario, mechanistic experiments DFT calculations have provided strong evidence cycle involving Pd(I)/diboryl carbon radical intermediates.

Язык: Английский

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