68716-52-9Relevant articles and documents
Development and Mechanistic Studies of Iron-Catalyzed Construction of Csp2-B Bonds via C-O Bond Activation
Geng, Shasha,Zhang, Juan,Chen, Shuo,Liu, Zhengli,Zeng, Xiaoqin,He, Yun,Feng, Zhang
supporting information, p. 5582 - 5588 (2020/07/08)
Herein we describe an iron-catalyzed borylation of alkenyl and aryl carbamates through the activation of a C-O bond. This protocol exhibits high efficiency, a broad substrate scope, and the late-stage borylation of biorelevant compounds, thus providing potential applications in medicinal chemistry. Moreover, this method enables orthogonal transformations of phenol derivatives and also offers good opportunities for the synthesis of multisubstituted arenes. Preliminary mechanistic studies suggest that a FeII/FeIII catalytic cycle via a radical pathway might be involved in the reaction.
Visible-Light-Induced Ni-Catalyzed Radical Borylation of Chloroarenes
Tian, Ya-Ming,Guo, Xiao-Ning,Krummenacher, Ivo,Wu, Zhu,Nitsch, J?rn,Braunschweig, Holger,Radius, Udo,Marder, Todd B.
supporting information, p. 18231 - 18242 (2020/11/02)
A highly selective and general photoinduced C-Cl borylation protocol that employs [Ni(IMes)2] (IMes = 1,3-dimesitylimidazoline-2-ylidene) for the radical borylation of chloroarenes is reported. This photoinduced system operates with visible light (400 nm) and achieves borylation of a wide range of chloroarenes with B2pin2 at room temperature in excellent yields and with high selectivity, thereby demonstrating its broad utility and functional group tolerance. Mechanistic investigations suggest that the borylation reactions proceed via a radical process. EPR studies demonstrate that [Ni(IMes)2] undergoes very fast chlorine atom abstraction from aryl chlorides to give [NiI(IMes)2Cl] and aryl radicals. Control experiments indicate that light promotes the reaction of [NiI(IMes)2Cl] with aryl chlorides generating additional aryl radicals and [NiII(IMes)2Cl2]. The aryl radicals react with an anionic sp2-sp3 diborane [B2pin2(OMe)]- formed from B2pin2 and KOMe to yield the corresponding borylation product and the [Bpin(OMe)]?- radical anion, which reduces [NiII(IMes)2Cl2] under irradiation to regenerate [NiI(IMes)2Cl] and [Ni(IMes)2] for the next catalytic cycle.
Iron-Catalyzed Borylation of Aryl Chlorides in the Presence of Potassium t-Butoxide
Yoshida, Takumi,Ilies, Laurean,Nakamura, Eiichi
, p. 3199 - 3203 (2017/06/09)
A catalytic amount of an inorganic iron salt such as Fe(acac)3 catalyzes borylation of various aryl and heteroaryl chlorides with bis(pinacolato)diboron, where the presence of potassium t-butoxide is crucially important. The alkoxide is considered to produce in situ an electron-rich iron alkoxide complex as the active species. The reaction requires only an iron salt and potassium t-butoxide as promoters and is easily scalable. The arylboron compound prepared by this reaction can be further coupled in situ with an aryl halide under the Suzuki-Miyaura conditions.
Radical Metal-Free Borylation of Aryl Iodides
Pinet, Sandra,Liautard, Virginie,Debiais, Mégane,Pucheault, Mathieu
, p. 4759 - 4768 (2017/10/03)
A simple metal-free borylation of aryl iodides mediated by a fluoride sp 2 -sp 3 diboron adduct is described. The reaction conditions are compatible with various functional groups. Electronic effects of substituents do not affect the borylation while steric hindrance does. The reaction proceeds via a radical mechanism in which pyridine serves to stabilize the boryl radicals, generated in situ.
Application of cooperative iron/copper catalysis to a palladium-free borylation of aryl bromides with pinacolborane
Labre, Flavien,Gimbert, Yves,Bannwarth, Pierre,Olivero, Sandra,Dunach, Elisabet,Chavant, Pierre Y.
supporting information, p. 2366 - 2369 (2014/05/20)
A new cooperative copper/iron catalysis for the borylation of various aryl bromides with pinacolborane, at -10 °C, is reported. Use of the toxic, precious metal Pd is avoided. The mechanism of the protodebromination side reaction is discussed.
Palladium-catalyzed borylation of aryl halides or triflates with dialkoxyborane: A novel and facile synthetic route to arylboronates
Murata, Miki,Oyama, Takashi,Watanabe, Shinji,Masuda, Yuzuru
, p. 164 - 168 (2007/10/03)
A direct borylation of aryl halides or triflates with dialkoxyborane was investigated. The coupling reaction of pinacolborane with aryl halides or triflates in the presence of a catalytic amount of PdCl2(dppf) together with a base provided arylboronates in high yields. The product distributions were strongly dependent on the base employed, and the tertiary amine, especially Et3N, was effective for the selective formation of the boron-carbon bond. The reaction conditions were so mild that arylboronates having a variety of functional groups such as carbonyl, cyano, and nitro groups were readily prepared.
