1131912-76-9Relevant articles and documents
A Copper(I)-Catalyzed Radical-Relay Reaction Enabling the Intermolecular 1,2-Alkylborylation of Unactivated Olefins
Akiyama, Sota,Oyama, Natsuki,Endo, Tsubura,Kubota, Koji,Ito, Hajime
, p. 5260 - 5268 (2021)
The first catalytic intermolecular 1,2-alkylborylation reaction via a radical-relay mechanism between unactivated olefins, bis(pinacolato)diboron, and an alkyl electrophile is reported. Successful implementation of this method requires that the competing boryl substitution of the alkyl electrophile is retarded to facilitate the radical relay. This challenge was overcome using electronically or sterically demanding alkyl electrophiles, which results in the simultaneous and highly regioselective introduction of a gem-difluoro, monofluoro, tertiary, or secondary alkyl group and a boryl group across the C=C double bond.
Zinc-catalyzed borylation of primary, secondary and tertiary alkyl halides with alkoxy diboron reagents at room temperature
Bose, Shubhankar Kumar,Fucke, Katharina,Liu, Lei,Steel, Patrick G.,Marder, Todd B.
, p. 1799 - 1803 (2014)
A new catalytic system based on a ZnII NHC precursor has been developed for the cross-coupling reaction of alkyl halides with diboron reagents, which represents a novel use of a Group XII catalyst for C=X borylation. This approach gives borylations of unactivated primary, secondary, and tertiary alkyl halides at room temperature to furnish alkyl boronates, with good functional-group compatibility, under mild conditions. Preliminary mechanistic investigations demonstrated that this borylation reaction seems to involve one-electron processes. Coupling a la carte: A catalytic system based on a ZnII N-heterocyclic carbene precursor has been developed for the cross-coupling reaction of alkyl halides with diboron reagents (see scheme). This is a novel use of a Group 12 catalyst for C=X borylation. IMes=1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene. Copyright
Photoinduced decarboxylative borylation of carboxylic acids
Fawcett, Alexander,Pradeilles, Johan,Wang, Yahui,Mutsuga, Tatsuya,Myers, Eddie L.,Aggarwal, Varinder K.
, p. 283 - 286 (2017)
The conversion of widely available carboxylic acids into versatile boronic esters would be highly enabling for synthesis. We found that this transformation can be effected by illuminating the N-hydroxyphthalimide ester derivative of the carboxylic acid under visible light at room temperature in the presence of the diboron reagent bis(catecholato)diboron. A simple workup allows isolation of the pinacol boronic ester. Experimental evidence suggests that boryl radical intermediates are involved in the process. The methodology is illustrated by the transformation of primary, secondary, and tertiary alkyl carboxylic acids as well as a diverse range of natural-product carboxylic acids, thereby demonstrating its broad utility and functional group tolerance.
Chromium-Catalyzed Borylative Coupling of Aliphatic Bromides with Pinacolborane by Hydrogen Evolution
Fu, Aiping,Li, Chao,Luo, Meiming,Zeng, Xiaoming,Zhao, Lixing
supporting information, p. 2204 - 2208 (2021/06/28)
The chromium-catalyzed borylative coupling between aliphatic bromides and pinacolborane (HBpin) is described. This reaction was promoted by low-cost and bench-stable CrCl3as a precatalyst combined with 4,4′-di-tert-butyl-2,2′-dipyridyl and aluminum, presenting a rare example of using HBpin as a borane reagent by coupling with alkyl bromides in forming borylated alkanes. Mechanistic studies indicate that aluminum plays important roles in the formation of reactive Cr species and aliphatic radicals, which lead to (alkyl)Cr by reaction with HBpin to give the products.
Transition metal- And light-free radical borylation of alkyl bromides and iodides using silane
Mo, Fanyang,Sun, Beiqi,Zheng, Sihan
supporting information, p. 5674 - 5677 (2021/06/16)
We report operationally simple and neutral conditions for borylation of alkyl bromides and iodides to alkyl boronic esters under transition metal- and light-free conditions. A series of substrates with a wide range of functional groups were effectively transformed into the borylation products in moderate to good yields. Mechanistic studies, including radical clock experiments and DFT calculations, gave detailed insight into the radical borylation process.
