Controllable Regiodivergent Alkynylation of 1,3‐Bis(Boronic) Esters Activated by Distinct Organometallic Reagents DOI
Ang Chen, Qiao Yang, De‐Wei Gao

и другие.

Angewandte Chemie, Год журнала: 2023, Номер 135(48)

Опубликована: Окт. 18, 2023

Abstract 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

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

Jianfei Ge,

Xi‐Zhang Zou,

Xinru Liu

и другие.

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

Процитировано

27
Cobalt‐Catalyzed Photo‐Semipinacol Rearrangement of Unactivated Allylic Alcohols DOI Creative Commons
Henry Lindner, Erick M. Carreira

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(35)

Опубликована: Июнь 7, 2024

We report a photochemical method for the semipinacol rearrangement of unactivated allylic alcohols. Aliphatic as well aromatic groups participate migrating groups, yielding variety α,α-disubstituted ketones. The reaction proceeds under mild conditions and is compatible with ethers, esters, halides, nitriles, carbamates, substituted arenes. operationally simple fully catalytic prescribe 1 mol % benzothiazinoquinoxaline organophotocatalyst, 0.5 Co-salen, 10 lutidinium triflate and, importantly, display reactivity complementary to procedures employing Brønsted acid. showcase utility protocol in late-stage drug diversifications.

Язык: Английский

Процитировано

9
β-Boron Effect Enables Regioselective and Stereospecific Electrophilic Addition to Alkenes DOI
Yin Li,

Wen‐Xin Fan,

Shuang Luo

и другие.

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(13), С. 7548 - 7558

Опубликована: Март 22, 2023

Electrophilic addition to alkenes is a textbook-taught reaction, yet it not always possible control the regioselectivity of unsymmetrical 1,2-disubstituted substrates. We report observation and applications β-boron effect that accounts for high in electrophilic reactions allylic MIDA (N-methyliminodiacetic acid) boronates. While well-established β-silicon bears partial resemblance observed reactivity, silyl group typically lost during functionalization. In contrast, boryl moiety retained product when B(MIDA) used as nucleophilic stabilizer. Mechanistic studies elucidate origin this demonstrate how σ(C–B) hyperconjugation helps stabilize incipient carbocation. This transformation represents rare example stereospecific hydrohalogenation secondary allyl MIDA-boronates proceeds syn-fashion.

Язык: Английский

Процитировано

16
Catalyst-Enabled Stereodivergence in Photochemical Atom Transfer Radical Addition (ATRA) of α-Iodoboronic Esters to Alkynes DOI

Qi Fan,

Jiawu Huang,

Shuang Lin

и другие.

ACS Catalysis, Год журнала: 2023, Номер 14(1), С. 299 - 307

Опубликована: Дек. 16, 2023

The atom transfer radical addition (ATRA) to alkynes is a valuable strategy for the synthesis of allylic substituted molecules, yet it has not been applied boronic acids or their esters, which are important building blocks in organic synthesis. inherent challenge ATRA reactions control geometric selectivity. By employing different alkene isomerization techniques, namely, photochemical uphill catalysis and manganese-catalyzed halogen-abstraction/radical rebound processes, we able synthesize both isomers iodinated esters stereoselective manner. Mechanistic investigations reveal dual functionalities catalysts, acting as catalysts processes. protocols feature broad substrate scope good functional group tolerance. Importantly, iodo boryl moieties within products provide orthogonal handles further synthetic manipulations. employed here should inspire more efforts toward alkynes.

Язык: Английский

Процитировано

12
Radical Ring-Opening Fluorosulfonylation of Methylenecyclobutanols via Electron Donor–Acceptor Photoactivation DOI
Tianyu He,

Chaoqiang Liang,

Ping Jiang

и другие.

Organic Letters, Год журнала: 2024, Номер 26(26), С. 5577 - 5581

Опубликована: Июнь 24, 2024

A visible-light-mediated catalyst- and additive-free method for radical ring-opening fluorosulfonylation of methylenecyclobutanols is reported. Sulfuryl chlorofluoride acts as a FSO

Язык: Английский

Процитировано

5
Cu-catalyzed carboboration of acetylene with Michael acceptors DOI Creative Commons

Tairan Cheng,

Boxiang Liu, Rui Wu

и другие.

Chemical Science, Год журнала: 2022, Номер 13(25), С. 7604 - 7609

Опубликована: Янв. 1, 2022

A copper-catalyzed three-component carboboration of acetylene with B 2 Pin and Michael acceptors was achieved. The small molecule enabled faster rate borylcupration easier C–C bond formation compared substituted alkynes.

Язык: Английский

Процитировано

18
Boron‐Copper 1,3‐Rearrangement: the New Concept Behind the Boryl Migration from C(sp2) in Alkenyl Boranes to C(sp3) DOI Creative Commons
Paula Dominguez‐Molano,

Rosemary Weeks,

Ricardo J. Maza

и другие.

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(30)

Опубликована: Май 11, 2023

Regioselective borylcupration of borylated skipped (Z)-dienes generates diborylated alkylcopper species that are involved in an intramolecular stereospecific B/Cu 1,3-rearrangement by migration Bpin moiety from C(sp2 ) to C(sp3 ). DFT mechanistic studies showed boryl occurs through the formation 4-membered boracycle intermediate with a moderate free-energy barrier. Moreover, use KOMe forms stable Lewis base adducts moieties blocks reaction. Subsequently 1,3-boron shift, situ electrophilic trapping allows selective C-H, C-C and C-X bonds, followed cross coupling giving access cyclic functionalized alkylidenecyclohexanes or alkylidenecyclobutanes.

Язык: Английский

Процитировано

10
Synthesis of highly substituted 1,3-dienes through halonium promoted 1,2-sulfur migration of propargylic thioethers DOI Creative Commons
Clara Martínez‐Núñez, Noelia Velasco, Roberto Sanz

и другие.

Chemical Communications, Год журнала: 2024, Номер 60(13), С. 1794 - 1797

Опубликована: Янв. 1, 2024

Highly regio- and diastereoselective synthesis of 2-thiorganyl 1-bromo or 1-iodo-1,3-dienes is reported via 1,2-sulfur migration propargylic sulfides. These dienes are precursors thiophenes selenophenes by reaction with sulfur selenium.

Язык: Английский

Процитировано

4
A Boron Scan of Ethyl Acetoacetate Leads to Versatile Building Blocks DOI Creative Commons

Alina Trofimova,

Brandon White, Diego B. Diaz

и другие.

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(15)

Опубликована: Янв. 26, 2024

Abstract Discovered in the 19th century, ethyl acetoacetate has been central to development of organic chemistry, including its pedagogy and applications. In this study, we present borylated derivatives venerable molecule. A boron handle installed at either ‐ or ‐position by homologation acyl‐MIDA ( N ‐methyliminodiacetic acid) boronates with diazoacetates. Either alkyl boryl groups were found migrate regiochemistry being a function steric bulk diazo species. Boryl ‐ketoesters can be further modified into pyrazolones oximes, thereby expanding synthetic toolkit offering opportunities for additional modifications.

Язык: Английский

Процитировано

4
Divergent Synthesis of 1,1-Carbonyl Amino Alkyl Borons from Indoles DOI

Mengyuan Hou,

Yahao Wang,

Puhui Li

и другие.

Organic Letters, Год журнала: 2023, Номер 25(22), С. 4038 - 4043

Опубликована: Май 25, 2023

α-Boryl carbonyl species and α-boryl amino compounds are valuable important frameworks in organic synthesis. However, the strategies that could merge two scaffolds into one compound, named 1,1-carbonyl alkyl boron, elusive underdeveloped. Herein, we present an efficient method address this gap produce borons from readily accessible indoles via oxidation by m-CPBA or oxone. This reaction features operational simplicity, divergent synthesis, broad substrate scope, products.

Язык: Английский

Процитировано

8