338998-93-9

Basic information

• Product Name: 2-Methylfurane-5-boronic acid pinacol ester
• Synonyms: 2-Methylfurane-5-boronic acid pinacol ester;5-Methyl-2-furanboronic acid pinacol ester;5-Methylfuran-2-boronic acid p;5-Methylfuran-2-boronic acid pinacol ester 95%;5-Methyl-2-(4,4,5,5-tetramethyl-1,3,2-dioxoborolan-2-yl)furan, 2-(5-Methylfur-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane
• CAS NO: 338998-93-9
• Molecular Formula: C₁₁H₁₇BO₃
• Molecular Weight: 208.06
• Mol File: 338998-93-9.mol

Chemical Properties

• Boiling Point: 277.794 °C at 760 mmHg
• Flash Point: 121.806 °C
• Appearance: /
• Density: 1.023 g/mL at 25 °C
• Vapor Pressure: 0.00748mmHg at 25°C
• Refractive Index: n20/D1.476
• Storage Temp.: 2-8°C
• CAS DataBase Reference: 2-Methylfurane-5-boronic acid pinacol ester(CAS DataBase Reference)
• NIST Chemistry Reference: 2-Methylfurane-5-boronic acid pinacol ester(338998-93-9)
• EPA Substance Registry System: 2-Methylfurane-5-boronic acid pinacol ester(338998-93-9)

Safety Data

• WGK Germany: 3
• Hazardous Substances Data: 338998-93-9(Hazardous Substances Data)

Usage

Uses

Used in Organic Synthesis:
2-Methylfurane-5-boronic acid pinacol ester is used as a reagent for the borylation of furans, pyrroles, and other organic reactions. Its boronic acid functionality enables it to undergo Suzuki-Miyaura cross-coupling reactions, which are widely used in the synthesis of complex organic molecules, including pharmaceuticals, agrochemicals, and advanced materials.
Used in Pharmaceutical Industry:
In the pharmaceutical industry, 2-Methylfurane-5-boronic acid pinacol ester is used as a key intermediate in the synthesis of various biologically active compounds. Its ability to form stable boron-containing intermediates makes it a valuable building block for the development of new drugs with potential applications in the treatment of various diseases.
Used in Material Science:
2-Methylfurane-5-boronic acid pinacol ester is also utilized in the field of material science, where it is employed in the synthesis of novel materials with unique properties. Its incorporation into polymers and other materials can lead to the development of advanced materials with improved mechanical, thermal, and electrical properties.

InChI:InChI=1/C11H17BO3/c1-8-6-7-9(13-8)12-14-10(2,3)11(4,5)15-12/h6-7H,1-5H3

Upstream product

• 534-22-5 2-methylfuran 
• 25015-63-8 4,4,5,5-tetramethyl-[1,3,2]-dioxaboralane 
• 557087-01-1 2-dimethylamino-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 
• 76-09-5 2,3-dimethyl-2,3-butane diol 
• 680192-98-7 deutero-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 
• 73183-34-3 bis(pinacol)diborane 

Downstream Products

• 952289-55-3 C₂₃H₂₇FN₄O₄S 
• 1430727-82-4 N-[3-(5-methyl-furan-2-yl)-5-nitro-phenyl]-acetamide 
• 1438894-26-8 2-(N,N-dibenzylamino)-5-(5-methylfuran-2-yl)pyridine 
• 1846570-31-7 CM-272 
• 1202402-40-1 (S)-7-(5-methylfuran-2-yl)-3-((6-(([tetrahydrofuran-3-yl]oxy)methyl)pyridin-2-yl)methyl)-3H-[1,2,3 ]triazolo[4,5-d]pyrimidin-5-amine 
• 953392-42-2 N₁-[4-fluoro-3-({[3-fluoro-4-(5-methyl-2-furanyl)phenyl]sulfonyl}amino)phenyl]-2-methylalaninamide hydrochloride 
• 1613043-31-4 1-benzyloxycarbonyl-5-(5-methylfuran-2-ylmethyl)indole 

Relevant articles and documents

C-H Borylation Catalysis of Heteroaromatics by a Rhenium Boryl Polyhydride

Transition metal complexes bearing metal-boron bonds are of particular relevance to catalytic C-H borylation reactions, with iridium polyboryl and polyhydrido-boryl complexes the current benchmark catalysts for these transformations. Herein, we demonstrate that polyhydride boryl phosphine rhenium complexes are accessible and catalyze the C-H borylation of heteroaromatic substrates. Reaction of [K(DME)(18-c-6)][ReH4(Bpin)(ν2-HBpin)(κ2-H2Bpin)] 1 with 1,3-bis(diphenylphosphino)propane (dppp) produced [K(18-c-6)][ReH4(ν2-HBpin)(dppp)] 2 through substitution of two equivalents of HBpin, and protonation of 2 formed the neutral complex [ReH6(Bpin)(dppp)] 3. Combined X-ray crystallographic and DFT studies show that 2 is best described as a σ-borane complex, whereas 3 is a boryl complex. Significantly, the boryl complex 3 acted as a catalyst for the C(sp2)-H borylation of a variety of heteroarenes (14 examples including furan, thiophene, pyrrole and indole derivatives) and displayed similar reactivity to the iridium analogues.

Manganese-Catalyzed C(sp2)-H Borylation of Furan and Thiophene Derivatives

Aryl boronic esters are bench-stable, platform building-blocks that can be accessed through metal-catalyzed aryl C(sp2)-H borylation reactions. C(sp2)-H bond functionalization reactions using rare- and precious-metal catalysts are well established, and while examples utilizing Earth-abundant alternatives have emerged, manganese catalysis remains lacking. The manganese-catalyzed C-H borylation of furan and thiophene derivatives is reported alongside an in situ activation method providing facile access to the active manganese hydride species. Mechanistic investigations showed that blue light irradiation directly affected catalysis by action at the metal center, that C(sp2)-H bond borylation occurs through a C-H metallation pathway, and that the reversible coordination of pinacolborane to the catalyst gave a manganese borohydride complex, which was as an off-cycle resting state.

Iron-catalysed C(sp2)-H borylation enabled by carboxylate activation

Arene C(sp2)-H bond borylation reactions provide rapid and efficient routes to synthetically versatile boronic esters. While iridium catalysts are well established for this reaction, the discovery and development of methods using Earth-abundant alternatives is limited to just a few examples. Applying an in situ catalyst activation method using air-stable and easily handed reagents, the iron-catalysed C(sp2)-H borylation reactions of furans and thiophenes under blue light irradiation have been developed. Key reaction intermediates have been prepared and characterised, and suggest two mechanistic pathways are in action involving both C-H metallation and the formation of an iron boryl species.

Method for efficiently catalyzing selective boronation reaction of five-membered heterocycle

The invention relates to a method for efficiently catalyzing a selective boronation reaction of a five-membered heterocycle. A heterocyclic borate product can be smoothly prepared through convenientlycatalyzing a selective boronation reaction of furan and thiophene derivatives and a cheap and easily available organic boron reagent under a mild condition by a cheap ruthenium metal complex taken asa catalyst. Compared with a reported method, the method of the invention has the obvious advantages of specific reaction selectivity, low catalyst dosage, convenience in operation, no need of addinga reaction solvent and the like, and an efficient and high-selectivity reaction strategy is provided for laboratory preparation or industrial production of the heterocyclic borate product.

C(sp2)-H Borylation of Heterocycles by Well-Defined Bis(silylene)pyridine Cobalt(III) Precatalysts: Pincer Modification, C(sp2)-H Activation, and Catalytically Relevant Intermediates

Well-defined bis(silylene)pyridine cobalt(III) precatalysts for C(sp2)-H borylation have been synthesized and applied to the investigation of the mechanism of the catalytic borylation of furans and 2,6-lutidine. Specifically, [(ArSiNSi)CoH3]·NaHBEt3 {ArSiNSi = 2,6-[EtNSi(NtBu)2CAr]2C5H3N, where Ar = C6H5 (1-H3·NaHBEt3) or 4-MeC6H4 (2-H3·NaHBEt3)} and trans-[(ArSiNSi)Co(H)2BPin] {Ar = C6H5 [1-(H)2BPin] or 4-MeC6H4 [2-(H)2BPin], and Pin = pinacolato} were prepared and employed as single-component precatalysts for the C(sp2)-H borylation of 2-methylfuran, benzofuran, and 2,6-lutidine. The cobalt(III) precursors, 2-H3·NaHBEt3 and 2-(H)2BPin, also promoted C(sp2)-H activation of benzofuran, yielding [(ArSiNSi)CoH(Bf)2] {Ar = 4-MeC6H4 [2-H(Bf)2], and Bf = 2-benzofuranyl}. Monitoring the catalytic borylation of 2-methylfuran and 2,6-lutidine by 1H NMR spectroscopy established the trans-dihydride cobalt(III) boryl as the catalyst resting state at low substrate conversions. At higher conversions, two distinct pincer modification pathways were identified, depending on the substrate and the boron source.

Regiodivergent hydrosilylation, hydrogenation, [2π + 2π]-cycloaddition and C-H borylation using counterion activated earth-abundant metal catalysis

The widespread adoption of earth-abundant metal catalysis lags behind that of the second- and third-row transition metals due to the often challenging practical requirements needed to generate the active low oxidation-state catalysts. Here we report the development of a single endogenous activation protocol across five reaction classes using both iron- and cobalt pre-catalysts. This simple catalytic manifold uses commercially available, bench-stable iron- or cobalt tetrafluoroborate salts to perform regiodivergent alkene and alkyne hydrosilylation, 1,3-diene hydrosilylation, hydrogenation, [2π + 2π]-cycloaddition and C-H borylation. The activation protocol proceeds by fluoride dissociation from the counterion, in situ formation of a hydridic activator and generation of a low oxidation-state catalyst.

Iridium(I)-Catalyzed C?H Borylation in Air by Using Mechanochemistry

Mechanochemistry has been applied for the first time to an iridium(I)-catalyzed C?H borylation reaction. By using either none or just a catalytic amount of a liquid, the mechanochemical C?H borylation of a series of heteroaromatic compounds proceeded in air to afford the corresponding arylboronates in good-to-excellent yields. A one-pot mechanochemical C?H borylation/Suzuki–Miyaura cross-coupling sequence for the direct synthesis of 2-aryl indole derivatives is also described. The present study constitutes an important milestone towards the development of industrially attractive solvent-free C?H bond functionalization processes in air.

Catalytic C?H Borylation Using Iron Complexes Bearing 4,5,6,7-Tetrahydroisoindol-2-ide-Based PNP-Type Pincer Ligand

Catalytic C?H borylation has been reported using newly designed iron complexes bearing a 4,5,6,7-tetrahydroisoindol-2-ide-based PNP pincer ligand. The reaction tolerated various five-membered heteroarenes, such as pyrrole derivatives, as well as six-membered aromatic compounds, such as toluene. Successful examples of the iron-catalyzed sp3 C?H borylation of anisole derivatives were also presented.

Alkylammoniotrifluoroborate functionalized polystyrenes: Polymeric pre-catalysts for the metal-free borylation of heteroarenes

Three polymeric versions of ansa-N,N-dialkylammoniumtrifluoroborate ambiphilic molecules based on the styrene motif (poly(1-NMe2H+-2-BF3--4-styrene) (P-Me), poly(1-NEt2H+-2-BF3--4-styrene) (P-Et) and poly(1-piperidinyl-H+-2-BF3--4-styrene) (P-Pip)) were synthesized, characterized and tested as heterogeneous pre-catalysts for the borylation of electron-rich heteroarenes. These heterogeneous versions of previously reported pre-catalysts show similar reactivity patterns and represent the first examples of solid-supported FLP metal-free catalysts for the C-H borylation of heteroarenes.

Practical and Scalable Synthesis of Borylated Heterocycles Using Bench-Stable Precursors of Metal-Free Lewis Pair Catalysts

A practical and scalable metal-free catalytic method for the borylation and borylative dearomatization of heteroarenes has been developed. This synthetic method uses inexpensive and conveniently synthesizable bench-stable precatalysts of the form 1-NHR2-2-BF3-C6H4, commercially and synthetically accessible heteroarenes as substrates, and pinacolborane as the borylation reagent. The preparation of several borylated heterocycles on 2 and 50 g scales was achieved under solvent-free conditions without the use of Schlenk techniques or a glovebox. A kilogram-scale borylation of one of the heteroarene substrates was also achieved using this cost-effective green methodology to exemplify the fact that our methodology can be conveniently implemented in fine chemical industries.