Direct Light‐Enabled Access to α‐Boryl Radicals: Application in the Stereodivergent Synthesis of Allyl Boronic Esters** DOI Creative Commons

Alessandro Marotta,

Fang Hao,

Callum E. Adams

et al.

Angewandte Chemie, Journal Year: 2023, Volume and Issue: 135(34)

Published: June 16, 2023

Abstract Operationally simple strategies to assemble boron containing organic frameworks are highly enabling in synthesis. While conventional retrosynthetic logic has engendered many platforms focusing on the direct formation of C−B bonds, α‐boryl radicals have recently reemerged as versatile open‐shell alternatives access organoborons via adjacent C−C bond formation. Direct light‐enabled α‐activation is currently contingent photo‐ or transition metal‐catalysis activation efficiently generate radical species. Here, we disclose a facile α‐halo boronic esters using only visible light and Lewis base enable homolytic scission. Intermolecular addition styrenes facilitates rapid construction E ‐allylic esters. The simplicity permits strategic merger this construct with selective energy transfer catalysis complimentary stereodivergent synthesis Z

Language: Английский

The Impact of Boron Hybridisation on Photocatalytic Processes DOI Creative Commons

Alessandro Marotta,

Callum E. Adams,

John J. Molloy

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(38)

Published: June 24, 2022

Recently the fruitful merger of organoboron chemistry and photocatalysis has come to forefront organic synthesis, resulting in development new technologies access complex (non)borylated frameworks. Central success this combination is control boron hybridisation. Contingent on photoactivation mode, as its neutral planar form or tetrahedral boronate can be used regulate reactivity. This Minireview highlights current state art photocatalytic processes utilising compounds, paying particular attention role hybridisation for target transformation.

Language: Английский

Citations

55
Palladium‐Catalyzed Cascade Heck Coupling and Allylboration of Iododiboron Compounds via Diboryl Radicals DOI
Wei Yi, Xiaoyu Xie, Jiabin Liu

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(18)

Published: March 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.

Language: Английский

Citations

14
Photogeneration of α-Bimetalloid Radicals via Selective Activation of Multifunctional C1 Units DOI Creative Commons

Lewis McGhie,

Alessandro Marotta,

Patrick O. Loftus

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(23), P. 15850 - 15859

Published: May 28, 2024

Light-driven strategies that enable the chemoselective activation of a specific bond in multifunctional systems are comparatively underexplored comparison to transition-metal-based technologies, yet desirable when considering controlled exploration chemical space. With current drive discover next-generation therapeutics, reaction design enables strategic incorporation an sp3 carbon center, containing multiple synthetic handles for subsequent space would be highly enabling. Here, we describe photoactivation ambiphilic C1 units generate α-bimetalloid radicals using only Lewis base and light source directly activate C–I bond. Interception these transient with various SOMOphiles rapid synthesis organic scaffolds (B, Si, Ge) orthogonal activation. In-depth theoretical mechanistic studies reveal prominent role 2,6-lutidine forming photoactive charge transfer complex stabilizing situ generated iodine radicals, as well influential boron p-orbital activation/weakening This simple efficient methodology enabled expedient access functionalized 3D frameworks can further derivatized available technologies C–B C–Si

Language: Английский

Citations

13
PolyBorylated Alkenes as Energy‐Transfer Reactive Groups: Access to Multi‐Borylated Cyclobutanes Combined with Hydrogen Atom Transfer Event DOI Creative Commons
Nicole Hanania, Nadim Eghbarieh, Ahmad Masarwa

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(25)

Published: April 11, 2024

Abstract While polyborylated alkenes are being recognized for their elevated status as highly valuable reagents in modern organic synthesis, allowing efficient access to a diverse array of transformations, including the formation C−C and C‐heteroatom bonds, potential energy‐transfer reactive groups has remained unexplored. Yet, this holds key generating elusive biradical species, which can be captured by olefins, thereby leading construction new highly‐borylated scaffolds. Herein, we report designed strategy photosensitized [2+2]‐cycloadditions poly‐borylated with various olefins enabling regioselective synthesis cyclobutane motifs, 1,1‐di‐, 1,1,2‐tri‐, 1,1,2,2‐tetra‐borylated cyclobutanes. In fact, these compounds belong family that presently lacks synthetic pathways. Interestingly, when α‐methylstyrene was used, reaction involves an interesting 1,5‐hydrogen atom transfer (HAT). Mechanistic deuterium‐labeling studies have provided insight into outcome process. addition, cyclobutanes then demonstrated useful selective oxidation processes resulting cyclobutanones γ‐lactones.

Language: Английский

Citations

10
Construction of 1,3‐Diboryl Allenes from gem‐Iododiboron Compounds via Intermolecular Boryl Group Transfer† DOI Open Access
Ming Li, Yi Wei, Du Chen

et al.

Chinese Journal of Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 23, 2025

Comprehensive Summary Allenylboronates are valuable synthetic building blocks and have garnered significant interest. However, their 1,3‐diboyl substituted analogs not been reported. Herein, we disclosed a novel method for creating allenes from gem ‐iododiboron compounds alkynyl Grignard reagents. The starting materials initially converted into the corresponding propargylic ‐bis(boronates), which then undergo an intermolecular boryl group transfer to afford allenes, as confirmed by mechanistic studies. This features good tolerance steric hindrance is compatible with wide variety of functional groups.

Language: Английский

Citations

1
Alkyne synthesis through coupling of gem-diborylalkanes with carboxylic acid esters DOI
Wei Sun,

Liangxuan Xu,

Yucheng Qin

et al.

Nature Synthesis, Journal Year: 2023, Volume and Issue: 2(5), P. 413 - 422

Published: Feb. 23, 2023

Language: Английский

Citations

21
Direct Light‐Enabled Access to α‐Boryl Radicals: Application in the Stereodivergent Synthesis of Allyl Boronic Esters** DOI Creative Commons

Alessandro Marotta,

Fang Hao,

Callum E. Adams

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(34)

Published: June 16, 2023

Abstract Operationally simple strategies to assemble boron containing organic frameworks are highly enabling in synthesis. While conventional retrosynthetic logic has engendered many platforms focusing on the direct formation of C−B bonds, α‐boryl radicals have recently reemerged as versatile open‐shell alternatives access organoborons via adjacent C−C bond formation. Direct light‐enabled α‐activation is currently contingent photo‐ or transition metal‐catalysis activation efficiently generate radical species. Here, we disclose a facile α‐halo boronic esters using only visible light and Lewis base enable homolytic scission. Intermolecular addition styrenes facilitates rapid construction E ‐allylic esters. The simplicity permits strategic merger this construct with selective energy transfer catalysis complimentary stereodivergent synthesis Z

Language: Английский

Citations

21
Stereodefined polymetalloid alkenes synthesis via stereoselective boron-masking of polyborylated alkenes DOI Creative Commons
Nadim Eghbarieh, Nicole Hanania, Ahmad Masarwa

et al.

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: April 11, 2023

Polyborylated-alkenes are valuable polymetalloid reagents in modern organic synthesis, providing access to a wide array of transformations, including the construction multiple C-C and C-heteroatom bonds. However, because they contain similar boryl groups, many times their transformation faces main challenge controlling chemo-, regio- stereoselectivity. One way overcome these limitations is by installing different boron groups that can provide an opportunity tune reactivity toward better Yet, preparation polyborylated-alkenes containing has been rare. Herein we report concise, highly site-selective, stereoselective boron-masking strategies polyborylated alkenes. This achieved designed trifluorination MIDA-ation reactions readily available starting Additionally, trifluoroborylated-alkenes undergo stereospecific interconversion Bdan-alkenes. These transition-metal free general efficient method for conversion alkenes 1,1-di-, 1,2-di-, 1,1,2-tris-(borylated) BF

Language: Английский

Citations

18
Stereoselective Diels–Alder Reactions of gem-Diborylalkenes: Toward the Synthesis of gem-Diboron-Based Polymers DOI Creative Commons
Nadim Eghbarieh, Nicole Hanania, Alon Zamir

et al.

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(16), P. 6211 - 6220

Published: April 14, 2021

Although gem-diborylalkenes are known to be among the most valuable reagents in modern organic synthesis, providing a rapid access wide array of transformations, including construction C–C and C-heteroatom bonds, their use as dienophile-reactive groups has been rare. Herein we report Diels–Alder (DA) reaction (unsymmetrical) gem-diborylalkenes. These reactions provide general efficient method for stereoselective conversion rapidly 1,1-bisborylcyclohexenes. Using same DA manifold with borylated-dienes gem-diborylalkenes, also developed concise, highly regioselective synthesis 1,1,2-tris- 1,1,3,4-tetrakis(boronates)cyclohexenes, family compounds that currently lack synthetic access. Furthermore, DFT calculations provided insight into underlying factors control chemo-, regio-, stereoselectivity these reactions. This provides stereodivergent syntheses gem-diborylnorbornenes. The utility gem-diborylnorbornene building blocks was demonstrated by ring-opening metathesis polymerization (ROMP), modular approach first gem-diboron-based polymers. Additionally, polymers have successfully submitted postpolymerization modification Given its simplicity versatility, believe this novel ROMP holds great promise organoboron well organoboron-based it will result more transformations both academic industrial research.

Language: Английский

Citations

35
Photoredox/Cu‐Catalyzed Decarboxylative C(sp3)−C(sp3) Coupling to Access C(sp3)‐Rich gem‐Diborylalkanes DOI Creative Commons
Mingming Huang, Huaxing Sun,

Florian Seufert

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(33)

Published: May 31, 2024

Abstract gem ‐Diborylalkanes are highly valuable building blocks in organic synthesis and pharmaceutical chemistry due to their ability participate multi‐step cross‐coupling transformations, allowing for the rapid generation of molecular complexity. While progress has been made synthetic metholodology, construction β‐tertiary C(sp 3 )‐rich ‐diborylalkanes remains a challenge substrate limitations steric hindrance issues. An approach is presented that utilizes synergistic photoredox copper catalysis achieve efficient )−C(sp ) alkyl N ‐hydroxyphthalimide esters, which can easily be obtained from carboxylic acids, with diborylmethyl species, providing series 1°, 2°, even 3° β positions. Furthermore, this also applied complex medicinal compounds natural products, offering access complexity late‐stage functionalization drug candidates. Mechanistic experiments revealed Cu(I) species participated both process key bond‐forming step.

Language: Английский

Citations

5