953040-54-5

Usage

Uses

Used in Pharmaceutical and Material Sciences:
1-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrrole is used as a building block in the synthesis of new drugs and materials due to its ability to form strong covalent bonds with other molecules, enhancing the properties and applications of the resulting compounds.
Used in Organic Electronic Devices:
1-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrrole is studied for its potential applications in organic electronic devices, where its unique bonding and electronic properties can contribute to the development of advanced technologies.
Used as a Fluorescent Dye:
1-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrrole is also considered for use as a fluorescent dye, capitalizing on its optical properties for various analytical and diagnostic applications.

InChI:InChI=1/C11H18BNO2/c1-10(2)11(3,4)15-12(14-10)9-6-7-13(5)8-9/h6-8H,1-5H3

Upstream product

• 96-54-8 N-Methylpyrrole 
• 76-09-5 2,3-dimethyl-2,3-butane diol 
• 214360-77-7 3-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-pyrrole 
• 74-88-4 methyl iodide 
• 25015-63-8 4,4,5,5-tetramethyl-[1,3,2]-dioxaboralane 
• 365564-11-0 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-(triisopropylsilyl)pyrrole 
• 73183-34-3 bis(pinacol)diborane 
• 1412912-71-0 dichloro-N-methylpyrrole-3-ylborane 
• 55718-76-8 2-chloro-1,3,2-benzodioxaborole 

Downstream Products

• 1607005-69-5 4-chloro-6-(1-methyl-1H-pyrazol-4-yl)-7-(phenylsulfonyl)-7H-pyrrolo[2,3-d]pyrimidine 

Relevant academic research and scientific papers

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.

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.

PRECATALYSTS AND PROCESS FOR THE METAL-FREE FUNCTIONALIZATION OF SP2 CARBONS USING THE SAME

Precatalysts of formula I and IV, and processes for the functionalization of SP2-carbons using the same are described herein. The precatalysts comprise a fluoroborate salt protected intramolecular frustrated lewis pair (FLP). The precatalysts are bench stable with improved stability towards moisture and/or air. The precatalysts can be used to generate in situ the corresponding FLP catalyst.

Metal-Free Borylation of Heteroarenes Using Ambiphilic Aminoboranes: On the Importance of Sterics in Frustrated Lewis Pair C-H Bond Activation

Two novel frustrated Lewis pair (FLP) aminoboranes, (1-Pip-2-BH2-C6H4)2 (2; Pip = piperidyl) and (1-NEt2-2-BH2-C6H4)2 (3; NEt2 = diethylamino), were synthesized, and their structural features were elucidated both in solution and in the solid state. The reactivity of these species for the borylation of heteroarenes was investigated and compared to previously reported (1-TMP-2-BH2-C6H4)2 (1; TMP = tetramethylpiperidyl) and (1-NMe2-2-BH2-C6H4)2 (4; NMe2 = dimethylamino). It was shown that 2 and 3 are more active catalysts for the borylation of heteroarenes than the bulkier analogue 1. Kinetic studies and density functional theory calculations were performed with 1 and 2 to ascertain the influence of the amino group of this FLP-catalyzed transformation. The C-H activation step was found to be more facile with smaller amines at the expense of a more difficult dissociation of the dimeric species. The bench-stable fluoroborate salts of all catalysts (1F-4F) have been synthesized and tested for the borylation reaction. The new precatalysts 2F and 3F are showing higher reaction rates and yields for multigram-scale syntheses.

PROCESS FOR THE FUNCTIONALIZATION OF SP2-H CARBONS USING FRUSTRATED LEWIS PAIR CATALYSTS

A catalytic process for the metal-free functionalization of sp2-carbons is described herein. The catalytic process is suitable for forming borylated alkenes, arenes and heteroarenes and comprises the use of catalysts comprising a Frustrated Lewis Pair (FLP).

Bench-stable frustrated Lewis pair chemistry: Fluoroborate salts as precatalysts for the C-H borylation of heteroarenes

While the organotrifluoroborate group is commonly used as a leaving group in cross-coupling reactions, we now show that their high stability can be used to protect the Lewis acidic moieties of frustrated Lewis pair catalysts. Indeed, the air and moisture-stable trifluoro- and difluoroborate derivatives of bulky (tetramethylpiperidino)benzene are shown to be conveniently converted to their dihydroborane analogue which is known to activate small molecules. An efficient synthesis route to these stable and convenient precatalysts, their deprotection chemistry and their benchtop use for the dehydrogenative borylation of heteroarenes is presented.

A Palladium(II)-Catalyzed C-H Activation Cascade Sequence for Polyheterocycle Formation

Polyheterocycles are found in many natural products and are useful moieties in functional materials and drug design. As part of a program towards the synthesis of Stemona alkaloids, a novel palladium(II)-catalyzed C-H activation strategy for the construction of such systems has been developed. Starting from simple 1,3-dienyl-substituted heterocycles, a large range of polycyclic systems containing pyrrole, indole, furan and thiophene moieties can be synthesized in a single step. Don't overdo it: A palladium(II)-catalyzed C-H activation cascade sequence for the synthesis of polyheterocycles is reported. Aromatization of the initially formed dihydro species occurred with a quinone oxidant. In some cases the use of one equivalent of the oxidant enabled isolation of the dihydro species as a single isomer (see scheme; X=NMe, O, S).

Metal-free catalytic C-H bond activation and borylation of heteroarenes

Transition metal complexes are efficient catalysts for the C-H bond functionalization of heteroarenes to generate useful products for the pharmaceutical and agricultural industries. However, the costly need to remove potentially toxic trace metals from the end products has prompted great interest in developing metal-free catalysts that can mimic metallic systems.We demonstrated that the borane (1-TMP-2-BH2-C6H4)2 (TMP, 2,2,6,6-tetramethylpiperidine) can activate the C-H bonds of heteroarenes and catalyze the borylation of furans, pyrroles, and electron-rich thiophenes. The selectivities complement those observed with most transition metal catalysts reported for this transformation.

Mechanistic studies into amine-mediated electrophilic arene borylation and its application in MIDA boronate synthesis

Direct electrophilic borylation using Y2BCl (Y2 = Cl2 or o-catecholato) with equimolar AlCl3 and a tertiary amine has been applied to a wide range of arenes and heteroarenes. In situ functionalization of the ArBCl2 products is possible with TMS 2MIDA, to afford bench-stable and easily isolable MIDA-boronates in moderate to good yields. According to a combined experimental and computational study, the borylation of activated arenes at 20 C proceeds through an S EAr mechanism with borenium cations, [Y2B(amine)] +, the key electrophiles. For catecholato-borocations, two amine dependent reaction pathways were identified: (i) With [CatB(NEt 3)]+, an additional base is necessary to accomplish rapid borylation by deprotonation of the borylated arenium cation (σ complex), which otherwise would rather decompose to the starting materials than liberate the free amine to effect deprotonation. Apart from amines, the additional base may also be the arene itself when it is sufficiently basic (e.g., N-Me-indole). (ii) When the amine component of the borocation is less nucleophilic (e.g., 2,6-lutidine), no additional base is required due to more facile amine dissociation from the boron center in the borylated arenium cation intermediate. Borenium cations do not borylate poorly activated arenes (e.g., toluene) even at high temperatures; instead, the key electrophile in this case involves the product from interaction of AlCl3 with Y2BCl. When an extremely bulky amine is used, borylation again does not proceed via a borenium cation; instead, a number of mechanisms are feasible including via a boron electrophile generated by coordination of AlCl3 to Y2BCl, or by initial (heteroarene)AlCl3 adduct formation followed by deprotonation and transmetalation.

PROCESS FOR THE BORYLATION OF ARENES AND HETEROARYLS

This invention relates to a novel process for the borylation of arenes and heteroaryls. The present invention also provides novel borenium cations, which act as electrophiles for electrophilic substitution on the arene or heteroaryl ring, as well as to methodology for the preparation of these cations.