1242770-50-8Relevant articles and documents
Enantioselective Copper-Catalyzed Synthesis of Trifluoromethyl-Cyclopropylboronates
Altarejos, Julia,Carreras, Javier,Sucunza, David,Vaquero, Juan J.
, p. 6174 - 6178 (2021)
A copper-catalyzed enantioselective cyclopropanation involving trifluorodiazoethane in the presence of alkenyl boronates has been developed. This transformation enables the preparation of 2-substituted-3-(trifluoromethyl)cyclopropylboronates with high levels of stereocontrol. The products are valuable synthetic intermediates by transformation of the boronate group. This methodology can be applied to the synthesis of novel trifluoromethylated analogues of trans-2-arylcyclopropylamines, which are prevalent motifs in biologically active compounds.
Iron-Catalyzed Dehydrogenative Borylation of Terminal Alkynes
Wei, Duo,Carboni, Bertrand,Sortais, Jean-Baptiste,Darcel, Christophe
, p. 3649 - 3654 (2018)
The catalytic system based on Fe(OTf)2 (2.5 mol%) and DABCO (1 mol%) selectively promotes the dehydrogenative borylation of both aromatic and aliphatic terminal alkynes to afford alkynylboronate derivatives in the presence of 1 equiv. of pinaco
Aluminum-Catalyzed Selective Hydroboration of Nitriles and Alkynes: A Multifunctional Catalyst
Sarkar, Nabin,Bera, Subhadeep,Nembenna, Sharanappa
, p. 4999 - 5009 (2020)
The reaction of LH [L = {(ArNH)(ArN)-C=N-C=(NAr)(NHAr)}; Ar =2,6-Et2-C6H3] with a commercially available alane amine adduct (H3Al·NMe2Et) in toluene resulted in the formation of a conjugated bis-guanidinate (CBG)-supported aluminum dihydride complex, i.e., LAlH2 (1), in good yield. The new complex has been thoroughly characterized by multinuclear magnetic resonance, IR, mass, and elemental analyses, including single-crystal structural studies. Further, we have demonstrated the aluminum-catalyzed hydroboration of a variety of nitriles and alkynes. Moreover, aluminum-catalyzed hydroboration is expanded to more challenging substrates such as alkene, pyridine, imine, carbodiimide, and isocyanides. More importantly, we have shown that the aluminum dihydride catalyzed both intra- A nd intermolecular chemoselective hydroboration of nitriles and alkynes over other reducible functionalities for the first time.
Tropylium-Promoted Hydroboration Reactions: Mechanistic Insights Via Experimental and Computational Studies
Mai, Binh Khanh,Nguyen, Thanh Vinh,Ton, Nhan N. H.
, p. 9117 - 9133 (2021/07/19)
Hydroboration reaction of alkynes is one of the most synthetically powerful tools to access organoboron compounds, versatile precursors for cross-coupling chemistry. This type of reaction has traditionally been mediated by transition-metal or main group catalysts. Herein, we report a novel method using tropylium salts, typically known as organic oxidants and Lewis acids, to promote the hydroboration reaction of alkynes. A broad range of vinylboranes can be easily accessed via this metal-free protocol. Similar hydroboration reactions of alkenes and epoxides can also be efficiently catalyzed by the same tropylium catalysts. Experimental studies and DFT calculations suggested that the reaction follows an uncommon mechanistic pathway, which is triggered by the hydride abstraction of pinacolborane with tropylium ion. This is followed by a series ofin situcounterion-activated substituent exchanges to generate boron intermediates that promote the hydroboration reaction.
Electrochemical Hydroboration of Alkynes
Aelterman, Maude,Jubault, Philippe,Poisson, Thomas,Sayes, Morgane
supporting information, p. 8277 - 8282 (2021/05/27)
Herein we reported the electrochemical hydroboration of alkynes by using B2Pin2 as the boron source. This unprecedented reaction manifold was applied to a broad range of alkynes, giving the hydroboration products in good to excellent yields without the need of a metal catalyst or a hydride source. This transformation relied on the possible electrochemical oxidation of an in situ formed borate. This anodic oxidation performed in an undivided cell allowed the formation of a putative boryl radical, which reacted on the alkyne.
