408492-26-2

Usage

Uses

2-(3,5-Dibromophenyl) 4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Upstream product

• 108-36-1 1,3-dibromobenzene 
• 25015-63-8 4,4,5,5-tetramethyl-[1,3,2]-dioxaboralane 
• 73183-34-3 bis(pinacol)diborane 
• 626-39-1 1,3,5-trisbromobenzene 

Downstream Products

• 663180-98-1 methyl 3',5'-dibromo-[1,1'-biphenyl]-4-carboxylate 
• 16400-50-3 3,3',5,5'-tetrabromo-1,1'-biphenyl 
• 6311-60-0 3,5-dibromonitrobenzene 
• 942132-67-4 2-(3,5-dibromophenyl)-4,6-diphenylpyrimidine 
• 864736-96-9 1,3-dibromo-5-(3,3,3-trifluoroprop-1-en-2-yl)benzene 
• 943137-95-9 5-[5-(3,5-dibromophenyl)-4,5-dihydro-5-(trifluoromethyl)-3-isoxazolyl]-2-(1H-1,2,4-triazol-1-yl)benzonitrile 
• 626-41-5 3,5-dibromophenol 

Relevant academic research and scientific papers

Understanding the Activation of Air-Stable Ir(COD)(Phen)Cl Precatalyst for C-H Borylation of Aromatics and Heteroaromatics

A newly developed robust catalyst [Ir(COD)(Phen)Cl] (A) was used for the C-H borylation of three dozen aromatics and heteroaromatics with excellent yield and selectivity. Activation of the catalyst was identified by the use of catalytic amounts of water, alcohols, etc., when B2pin2 was used in noncoordinating solvents, while for THF catalytic use of HBpin was required. The results were on par with the in situ based expensive system [Ir(OMe)(COD)]2/dtbbpy or Me4Phen.

Sequential Ir/Cu-Mediated Method for the Meta-Selective C-H Radiofluorination of (Hetero)Arenes

This article describes a sequential Ir/Cu-mediated process for the meta-selective C-H radiofluorination of (hetero)arene substrates. In the first step, Ir-catalyzed C(sp2)-H borylation affords (hetero)aryl pinacolboronate (BPin) esters. The intermediate organoboronates are then directly subjected to copper-mediated radiofluorination with [18F]tetrabutylammonium fluoride to afford fluorine-18 labeled (hetero)arenes in high radiochemical yield and radiochemical purity. This entire process is performed on a benchtop without Schlenk or glovebox techniques and circumvents the need to isolate (hetero)aryl boronate esters. The reaction was automated on a TracerLab FXFN module with 1,3-dimethoxybenzene and a meta-tyrosine derivative. The products, [18F]1-fluoro-3,5-dimethoxybenzene and an 18F-labeled meta-tyrosine derivative, were obtained in 37 ± 5% isolated radiochemical yield and >99% radiochemical purity and 25% isolated radiochemical yield and 99% radiochemical purity, and 0.52 Ci/μmol (19.24 GBq/μmol) molar activity (Am), respectively.

Direct C?H Borylation of Arenes Catalyzed by Saturated Hydride-Boryl-Iridium-POP Complexes: Kinetic Analysis of the Elemental Steps

The saturated trihydride IrH3{κ3-P,O,P-[xant(PiPr2)2]} (1; xant(PiPr2)2=9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) activates the B?H bond of two molecules of pinacolborane (HBpin) to give H2, the hydride-boryl derivatives IrH2(Bpin){κ3-P,O,P-[xant(PiPr2)2]} (2) and IrH(Bpin)2{κ3-P,O,P-[xant(PiPr2)2]} (3) in a sequential manner. Complex 3 activates a C?H bond of two molecules of benzene to form PhBpin and regenerates 2 and 1, also in a sequential manner. Thus, complexes 1, 2, and 3 define two cycles for the catalytic direct C?H borylation of arenes with HBpin, which have dihydride 2 as a common intermediate. C?H bond activation of the arenes is the rate-determining step of both cycles, as the C?H oxidative addition to 3 is faster than to 2. The results from a kinetic study of the reactions of 1 and 2 with HBpin support a cooperative function of the hydride ligands in the B?H bond activation. The addition of the boron atom of the borane to a hydride facilitates the coordination of the B?H bond through the formation of κ1- and κ2-dihydrideborate intermediates.

meta-Nitration of Arenes Bearing ortho/para Directing Group(s) Using C?H Borylation

Herein, we report the meta-nitration of arenes bearing ortho/para directing group(s) using the iridium-catalyzed C?H borylation reaction followed by a newly developed copper(II)-catalyzed transformation of the crude aryl pinacol boronate esters into the corresponding nitroarenes in a one-pot fashion. This protocol allows the synthesis of meta-nitrated arenes that are tedious to prepare or require multistep synthesis using the existing methods. The reaction tolerates a wide array of ortho/para-directing groups, such as ?F, ?Cl, ?Br, ?CH3, ?Et, ?iPr ?OCH3, and ?OCF3. It also provides regioselective access to the nitro derivatives of π-electron-deficient heterocycles, such as pyridine and quinoline derivatives. The application of this method is demonstrated in the late-stage modification of complex molecules and also in the gram-scale preparation of an intermediate en route to the FDA-approved drug Nilotinib. Finally, we have shown that the nitro product obtained by this strategy can also be directly converted to the aniline or hindered amine through Baran's amination protocol.

Sterically controlled C-H/C-H homocoupling of arenes: Via C-H borylation

A mild one-pot protocol for the synthesis of symmetrical biaryls by sequential Ir-catalyzed C-H borylation and Cu-catalyzed homocoupling of arenes is described. The regiochemistry of the biaryl formed is sterically controlled as dictated by the C-H borylation step. The methodology is also successfully extended to heteroarenes. Some of the products obtained by this approach are impossible to obtain via the Ullmann or the Suzuki coupling protocols. Finally, we have shown a one-pot sequence describing C-H borylation/Cu-catalyzed homocoupling/Pd-catalyzed Suzuki coupling to obtain π-extended arene frameworks.

Double N,B-Type Bidentate Boryl Ligands Enabling a Highly Active Iridium Catalyst for C-H Borylation

Boryl ligands hold promise in catalysis due to their very high electron-donating property. In this communication double N,B-type boryl anions were designed as bidentate ligands to promote an sp2 C-H borylation reaction. A symmetric pyridine-con

Regioselective conversion of arenes to N-aryl-1,2,3-triazoles Using C-H Borylation

A one-pot protocol for the synthesis of N-aryl 1,2,3-triazoles from arenes by an iridium-catalyzed C-H borylation/copper catalyzed azidation/click sequence is described. 1mol % of Cu(OTf)2 was found to efficiently catalyze both the azidation and the click reaction. The applicability of this method is demonstrated by the late-stage chemoselective installation of 1,2,3-triazole moiety into unactivated molecules of pharmaceutical importance.

A one-pot, single-solvent process for tandem, catalyzed C-H borylation-Suzuki-Miyaura cross-coupling sequences

Methyl tert-butyl ether is a suitable solvent for iridium-catalyzed C-H borylation followed, in the same pot, by palladium-catalyzed Suzuki-Miyaura cross-coupling sequences, giving high yields of biaryls. Georg Thieme Verlag Stuttgart.

One-pot synthesis of arylboronic acids and aryl trifluoroborates by Ir-catalyzed borylation of arenes

(Chemical Equation Presented) The synthesis of arylboronic acids and aryl trifluoroborates in a one-pot sequence by Ir-calalyzed borylation of arenes is reported. To prepare the arylboronic acids, the Ir-catalyzed borylation is followed by oxidative cleavage of the boronic ester with NaIO4. To prepare the aryltrifluoroborate, the Ir-catalyzed borylation is followed by displacement of pinacol by KHF2. These two-step sequences give products that are more reactive toward subsequent chemistry than the initially formed pinacol boronates.

Electrochemical reduction of polyhalogenated aryl derivatives in the presence of pinacolborane: Electrosynthesis of functionalised arylboronic esters

The electroreduction of several dihalogenated aryl compounds was carried out in the presence of pinacolborane as the electrophile for the synthesis of halogenated arylboronic ester derivatives. The nature and the relative position of the halogen substituents strongly influence the boration results. The electroreduction of a trihalogenated derivative was also examined. Reactions were carried out in THF in a single-compartment cell in the presence of a Mg anode.