87100-28-5Relevant academic research and scientific papers
Cu-mediated: vs. Cu-free selective borylation of aryl alkyl sulfones
Hu, Jiefeng,Huang, Mingming,Marder, Todd B.,Radius, Udo,Tang, Man,Westcott, Stephen A.
supporting information, p. 395 - 398 (2022/01/19)
A Cu-catalysed borylation of aryl alkyl sulfones was developed for the high yield synthesis of versatile arylboronic esters using a readily prepared NHC-Cu catalyst. In addition, the selective cleavage of either alkyl(C)-sulfonyl or aryl(C)-sulfonyl bonds
Selective Benzylic CH-Borylations by Tandem Cobalt Catalysis
Bauer, Matthias,Ghosh, Pradip,Jacobi von Wangelin, Axel,Schoch, Roland
, (2021/11/27)
Metal-catalyzed C?H activations are environmentally and economically attractive synthetic strategies for the construction of functional molecules as they obviate the need for pre-functionalized substrates and minimize waste generation. Great challenges reside in the control of selectivities, the utilization of unbiased hydrocarbons, and the operation of atom-economical dehydrocoupling mechanisms. An especially mild borylation of benzylic CH bonds was developed with the ligand-free pre-catalyst Co[N(SiMe3)2]2 and the bench-stable and inexpensive borylation reagent B2pin2 that produces H2 as the only by-product. A full set of kinetic, spectroscopic, and preparative mechanistic studies are indicative of a tandem catalysis mechanism of CH-borylation and dehydrocoupling via molecular CoI catalysts.
Evaluation of the role of graphene-based Cu(i) catalysts in borylation reactions
Cid, M. B.,Díaz, Cristina,Franco, Mario,Lamsabhi, Al Mokhtar,Sainz, Raquel,Tortosa, Mariola
, p. 3501 - 3513 (2021/06/06)
Carbon-supported catalysts have been considered as macromolecular ligands which modulate the activity of the metallic catalytic center. Understanding the properties and the factors that control the interactions between the metal and support allows a fine tuning of the catalyzed processes. Although huge effort has been devoted to comprehending binding energies and charge transfer for single atom noble metals, the interaction of graphenic surfaces with cheap and versatile Cu(i) salts has been scarcely studied. A methodical experimental and theoretical analysis of different carbon-based Cu(i) materials in the context of the development of an efficient, general, scalable, and sustainable borylation reaction of aliphatic and aromatic halides has been performed. We have also examined the effect of microwave (MW) radiation in the preparation of these type of materials using sustainable graphite nanoplatelets (GNP) as a support. A detailed analysis of all the possible species in solution revealed that the catalysis is mainly due to an interesting synergetic Cu2O/graphene performance, which has been corroborated by an extensive theoretical study. We demonstrated through DFT calculations at a high level of theory that graphene enhances the reactivity of the metal in Cu2O against the halide derivative favoring a radical departure from the halogen. Moreover, this material is able to stabilize radical intermediates providing unexpected pathways not observed using homogeneous Cu(i) catalysed reactions. Finally, we proved that other common carbon-based supports like carbon black, graphene oxide and reduced graphene oxide provided poorer results in the borylation process.
The functionalization of benzene by boranes using trispyrazolylborate complexes
Vetter, Andrew J.,DiBenedetto, Tarah A.,Ritz, Mikhaila D.,Jones, William D.
, (2021/02/03)
The catalytic C[sbnd]H activation and borylation of arenes by trispyrazolylborate complexes is reported. Trispyrazolylborate rhodium and iridium complexes have been previously shown to activate a variety of C[sbnd]H bonds. Here, we show the catalytic borylation of arenes by the trispyrazolylborate ethylene complexes Tp'Rh(C2H4)2, and Tp'Ir(C2H4)2.
Carbon-carbon bond activation by B(OMe)3/B2pin2-mediated fragmentation borylation
Chen, Quan,Jiang, Jiachen,Wang, Li,Wu, Aizhen,Yin, Youzhi,Zhang, Hua,Zhang, Ke,Zhao, Mengzhen,Zhong, Qi,Zou, Youliang
, p. 15104 - 15109 (2021/12/09)
Selective carbon-carbon bond activation is important in chemical industry and fundamental organic synthesis, but remains challenging. In this study, non-polar unstrained Csp2-Csp3 and Csp2-Csp2 bond activation was achieved by B(OMe)3/B2pin2-mediated fragmentation borylation. Various indole derivatives underwent C2-regioselective C-C bond activation to afford two C-B bonds under transition-metal-free conditions. Preliminary mechanistic investigations suggested that C-B bond formation and C-C bond cleavage probably occurred in a concerted process. This new reaction mode will stimulate the development of reactions based on inert C-C bond activation. This journal is
Nickel-Catalyzed Ipso-Borylation of Silyloxyarenes via C-O Bond Activation
Pein, Wesley L.,Wiensch, Eric M.,Montgomery, John
supporting information, (2021/06/28)
The conversion of silyloxyarenes to boronic acid pinacol esters via nickel catalysis is described. In contrast to other borylation protocols of inert C-O bonds, the method is competent in activating the carbon-oxygen bond of silyloxyarenes in isolated aromatic systems lacking a directing group. The catalytic functionalization of benzyl silyl ethers was also achieved under these conditions. Sequential cross-coupling reactions were achieved by leveraging the orthogonal reactivity of silyloxyarenes, which could then be functionalized subsequently.
Photoinduced NaI-Promoted Radical Borylation of Alkyl Halides and Pseudohalides
Wang, Chenglan,Zhou, Lu,Yang, Kai,Zhang, Feng,Song, Qiuling
, p. 1825 - 1830 (2021/05/28)
A method for photoinduced NaI-promoted radical borylation of aliphatic halides and pseudohalides with bis(catecholato)diboron (B2cat2) as the boron source is introduced. The borylation reaction is operationally simple and shows high
(o-Phenylenediamino)borylstannanes: Efficient Reagents for Borylation of Various Alkyl Radical Precursors
Suzuki, Kensuke,Nishimoto, Yoshihiro,Yasuda, Makoto
supporting information, p. 3968 - 3973 (2020/12/30)
(o-Phenylenediamino)borylstannanes were newly synthesized to achieve radical boryl substitutions of a variety of alkyl radical precursors. Dehalogenative, deaminative, decharcogenative, and decarboxylative borylations proceeded in the presence of a radica
Arene borylation through C–H activation using Cu3(BTC)2 as heterogeneous catalyst
Dhakshinamoorthy, Amarajothi,García, Cristina Vallés,Concepcion, Patricia,Garcia, Hermenegildo
, p. 212 - 217 (2020/07/06)
C–H borylation by diborane is an important process to access organoboron compounds. Noble metals, including Ir and Rh-based complexes either in the form of homogeneous or heterogeneous catalysts, have been reported to promote arene C–H borylation. Recently, metal organic frameworks (MOFs) having Ir and Co as active sites have been used as catalysts, but they require co-catalysts. In the present study, commercially available Cu3(BTC)2 (BTC: 1,3,5-benzenetricarboxylate) MOF is reported as an effective catalyst to promote borylation of arenes through C–H activation employing bis(pinacolato)diboron (1) as reagent leading to benzylic and aromatic borylation products. Interestingly, other related MOFs like MIL-101(Cr) and Al(OH)(BDC) (BDC: 1,4-benzenedicarboxylate) do not exhibit catalytic activity under identical conditions. Mechanistic studies using in-situ IR spectroscopy reveal that Cu ions play a crucial role in activating the arene and B–B bond in 1.
Practical Synthesis of Allyl, Allenyl, and Benzyl Boronates through SN1′-Type Borylation under Heterogeneous Gold Catalysis
Miura, Hiroki,Hachiya, Yuka,Nishio, Hidenori,Fukuta, Yohei,Toyomasu, Tomoya,Kobayashi, Kosa,Masaki, Yosuke,Shishido, Tetsuya
, p. 758 - 766 (2021/02/03)
Efficient borylation of sp3 C-O bonds by supported Au catalysts is described. Au nanoparticles supported on TiO2 showed high activity under mild conditions employing low catalyst loading conditions without the aid of any additives, such as phosphine and bases. A variety of allyl, propargyl, and benzyl substrates participated in the heterogeneously catalyzed reactions to furnish the corresponding allyl, allenyl, and benzyl boronates in high yields. Besides, Au/TiO2 was also effective for the direct borylation of allylic and benzylic alcohols. A mechanistic investigation based on a Hammett study and control experiments revealed that sp3 C-O bond borylation over supported Au catalysts proceeded through SN1′-type mechanism involving the formation of a carbocationic intermediate. The high activity, reusability, and environmental compatibility of the supported Au catalysts as well as the scalability of the reaction system enable the practical synthesis of valuable organoboron compounds.
