3222-65-9

Usage

Structure

A carbon ring with a methyl group attached to the nitrogen atom and an oxygen atom adjacent to the carbon ring.

Derivative of

Isoquinoline

Usage

In organic synthesis and research as a building block for various other compounds

Biological activities

Inhibitor of cytochrome P450 enzymes and intermediate in the biosynthesis of the natural product, gramine

Potential applications

Anti-cancer and anti-inflammatory.

Upstream product

• 1532-72-5 isoquinoline N-oxide 
• 2181-42-2 trimethylsulphonium iodide 
• 75-65-0 tert-butyl alcohol 
• 119-65-3 isoquinoline 
• 80-43-3 bis(1-methyl-1-phenylethyl)peroxide 
• 1721-93-3 1-methylisoquinoline 

Downstream Products

• 1721-93-3 1-methylisoquinoline 
• 1015758-98-1 1-(4-methylbenzyl)isoquinoline 2-oxide 

Relevant academic research and scientific papers

C2-Selective C-H methylation of heterocyclic N-oxides with sulfonium ylides

A redox-neutral C2-selective methylation of heterocyclic N-oxides with sulfonium ylides is described herein. This report presents unprecedented findings for the utility of sulfonium ylides as the methylation source of N-heterocycles beyond the Corey-Chaykovsky reaction. Intriguingly, pyrrolidine plays a significant role in minimizing the reductive C2-methylation process. This method is characterized by its mild conditions, simplicity, and excellent site selectivity. The applicability of the developed protocol is showcased by the late-stage methylation and sequential transformations of complex drug molecules.

A Biocatalytic Synthesis of Heteroaromatic N-Oxides by Whole Cells of Escherichia coli Expressing the Multicomponent, Soluble Di-Iron Monooxygenase (SDIMO) PmlABCDEF

Aromatic N-oxides (ArN?OX) are desirable biologically active compounds with a potential for application in pharmacy and agriculture industries. As biocatalysis is making a great impact in organic synthesis, there is still a lack of efficient and convenient enzyme-based techniques for the production of aromatic N-oxides. In this study, a recombinant soluble di-iron monooxygenase (SDIMO) PmlABCDEF overexpressed in Escherichia coli was showed to produce various aromatic N-oxides. Out of 98 tested N-heterocycles, seventy were converted to the corresponding N-oxides without any side oxidation products. This whole-cell biocatalyst showed a high activity towards pyridines, pyrazines, and pyrimidines. It was also capable of oxidizing bulky N-heterocycles with two or even three aromatic rings. Being entirely biocatalytic, our approach provides an environmentally friendly and mild method for the production of aromatic N-oxides avoiding the use of strong oxidants, organometallic catalysts, undesirable solvents, or other environment unfriendly reagents. (Figure presented.).

Transition-Metal-Free Regioselective Alkylation of Quinoline N-Oxides via Oxidative Alkyl Migration and C?C Bond Cleavage of tert-/sec-Alcohols

An unprecedented C2-alkylation of quinoline N-oxide derivatives via C?C bond activation of tert- and sec-alkyl alcohol is described using hypervalent iodine (III) reagent PhI(OAc)2 (PIDA). This regioselective alkylation using mild hypervalent iodine reagents is more practical, operationally simple and transition metal free. The reaction proceeds efficiently with a broad range of substrates including quinoline, isoquinoline, and pyridine N-oxides using a variety of tert-/sec- alcohols. From experimental outcome, we also propose a rationalized mechanism, mediated by PIDA. (Figure presented.).

Development of one-pot benzylic amination reactions of azine N-oxides

An efficient one-pot synthetic methodology has been developed for the benzylic amination reactions of methyl-substituted azine N-oxides that operate under mild conditions. The reaction was found to tolerate quinoline and isoquinoline N-oxides with electron donating and withdrawing substituents as the electrophilic reaction partners as well as a broad range of nucleophilic primary, secondary and aromatic amines, affording the benzylic amination products in up to 82% yield.

A Multiheteroatom [3,3]-Sigmatropic Rearrangement: Disproportionative Entries into 2-(N-Heteroaryl)methyl Phosphates and α-Keto Phosphates

A novel multiheteroatom (N, O and P) [3,3]-sigmatropic rearrangement is disclosed, based on two important types of organophosphates, 2-(N-heteroaryl) methyl phosphates and α-keto phosphates, being accessed smoothly and efficiently.

Metal-free methylation of a pyridine N-oxide C-H bond by using peroxides

Metal-free methylation of a pyridine N-oxide C-H bond was developed using peroxide as a methyl reagent under neat conditions. Pyridine N-oxide derivatives with various groups (e.g., Cl, NO2, and OCH3) were all suitable substrates, and the desired products were obtained in moderate to excellent yields under standard conditions. Moreover, the methylation can be performed with a good yield on the gram-scale experiment. Tentative mechanistic studies show that the methylation is a classical radical process.

Site-selective sp2 and benzylic sp3 palladium-catalyzed direct arylation

Palladium-catalyzed site selective arylation reactions of both sp2 and benzylic sp3 sites on azine and diazine N-oxide substrates are described that occur in good to excellent yield and with complete selectivity for reaction at the desired position. These studies have uncovered the need to properly control the metal to ligand ratio in sp2 arylation and necessitated a complete reinvestigation of all reaction parameters for sp3 arylation. From these studies, the choice of base emerged as a pivotal component for site selectivity, pointing to its intimate involvement in the mechanism of direct arylation. These site selective reactions have been validated in both divergent and sequential derivatizations of heterocyclic compounds represent an attractive alternative to other routes to this class of molecule. Copyright

N-oxidation of 2-substituted pyridines and quinolines by dimethyldioxirane: Kinetics and steric effects

The oxidation of 2-substituted pyridines and selected N-containing aromatic heterocycles by dimethyldioxirane (1) produced the corresponding N-oxides as the sole products, quantitatively in most cases. The second order rate constants for N-oxidation by 1 in dried acetone at 23°C were determined for a series of 2-substituted pyridines 2-10, quinolines 11-14 and isoquinolines 15,16. An excellent correlation of log k2 with Taft (σ*) constants was obtained for 2-substituted pyridines (R = Me, Et, Prn, Pr i, 3-pentyl) with the exception of the data for 2-f-butylpyridine. The results for the substituted quinolines and isoquinolines followed the same trends observed with the pyridines. Steric effects due to 2-substitution and periinteractions can substantially reduce reactivity. The results provide insights into the geometrical requirements for N-oxidation by dimethyldioxirane.