Synthesis of N-Alkyl Substituted Benzimidazoquinazolinones

Aromatic N-heterocycles, especially benzimidazoquinazolinones featuring alkyl chains, hold significant pharmaceutical relevance. Here, we introduce a streamlined one-pot, 2-fold Cu-catalyzed C-N bond formation protocol for the efficient synthesis of diverse N-alkyl benzimidazoquinazolinone derivatives. This method showcases a broad substrate scope, leveraging readily accessible alkyl halides and delivers the desired cyclized products in excellent yields. Additionally, the methodology enabled the synthesis of an antitumor agent with satisfactory yield, highlighting its utility in medicinal chemistry endeavors.

Divergent Approach for Regioselective Synthesis of Linearly and Angularly Fused Benzoimidazoquinazolinones from Isatoic Anhydrides

Ph₃P-I₂-mediated condensation reactions of isatoic anhydrides and o-phenylenediamines have been developed for the regioselective syntheses of a wide range of linearly and angularly fused benzoimidazoquinazolinones. The selectivity of the products relies on the generation of either highly electrophilic oxyphosphonium or less reactive imidate intermediates. A direct amine attack at the C-2 position of the oxyphosphonium intermediate presumably drives the reaction toward the linearly fused products, whereas an attack of the diamine at the C-4 position of the in situ generated cyclic imidate leads to the angularly fused derivatives. This strategy serves as a practical handle for the efficient synthesis of other related heterocycles.

Recent advances in the synthesis of bridgehead (or ring-junction) nitrogen heterocycles via transition metal-catalyzed C–H bond activation and functionalization

An update on recent advances in the synthesis of bridgehead nitrogen fused heterocycles via transition metal-catalyzed C–H activation and functionalization is reported.

[Cp*RhIII ]/Ionic Liquid as a Highly Efficient and Recyclable Catalytic Medium for C-H Amidation

A [Cp*Rh^III ]-catalyzed direct C-H amidation is carried out in ionic liquid. Both C(sp² )-H bonds of (hetero)arenes and alkenes and unactivated C(sp³ )-H bonds can be easily amidated with high functional-group tolerance and excellent yields under these conditions. Notably, using [Cp*Rh^III ]/[BMIM]BF₄ (BMIM=1-butyl-3-methylimidazolium) as the green and recyclable medium is environmentally benign, in light of characteristics such as the reusability of the expensive rhodium catalyst, avoidance of highly toxic organic solvents, and mild reaction conditions, as well as a short reaction time.

Metal-free C(sp2)–H functionalization of azoles: K2CO3/I2-mediated oxidation, imination, and amination

We report metal-free one-pot C2−H oxidation, imination, and amination of several azoles from azolium salts by using a commercially available simple and efficient reagent combination K₂CO₃/I₂.

Transition Metal-Catalyzed C-H Amination: Scope, Mechanism, and Applications

Catalytic transformation of ubiquitous C-H bonds into valuable C-N bonds offers an efficient synthetic approach to construct N-functionalized molecules. Over the last few decades, transition metal catalysis has been repeatedly proven to be a powerful tool for the direct conversion of cheap hydrocarbons to synthetically versatile amino-containing compounds. This Review comprehensively highlights recent advances in intra- and intermolecular C-H amination reactions utilizing late transition metal-based catalysts. Initial discovery, mechanistic study, and additional applications were categorized on the basis of the mechanistic scaffolds and types of reactions. Reactivity and selectivity of novel systems are discussed in three sections, with each being defined by a proposed working mode.

Cu-catalyzed C–H amination/Ullmann N-arylation domino reaction: a straightforward synthesis of 9,14-diaryl-9,14-dihydrodibenzo[a,c]phenazine

9,14-Diaryl-9,14-dihydrodibenzo[a,c]phenazine has been synthesized via Cu-catalyzed C–H amination/Ullmann N-arylation domino reaction of phenanthrene-9,10-diamine with aryl iodides.

Recent Trends in Copper-Catalyzed C-H Amination Routes to Biologically Important Nitrogen Scaffolds

Nitrogen-containing heterocycles have found remarkable applications in natural product research, material sciences, and pharmaceuticals. Although the synthesis of this interesting class of compounds attracted the interest of generations of organic chemists, simple and straightforward assembly methods based on transition-metal catalysis have regularly been elusive. The recent advancements in the development of C-H functionalization have helped in accomplishing the synthesis of a variety of complex heterocycles from simple precursors. This Focus Review summarizes the recent advances in one particular field: the copper-catalyzed C-N bond formation reactions via C-H bond functionalization to furnish a comprehensive range of nitrogen heterocycles. Applicability and synthetic feasibility of a particular reaction represent major requirements for the inclusion in this review.