Microwave-Assisted Synthesis of Fused Polycyclic Six-MemberedN-Heterocycles

Recent Advances in the Oxone-Mediated Synthesis of Heterocyclic Compounds

Oxone is a commercially available oxidant, composed of a mixture of three inorganic species, being the potassium peroxymonosulfate (KHSO5) the reactive one. Over the past few decades, this cheap and environmentally friendly oxidant has become a powerful tool in organic synthesis, being extensively employed to mediate the construction of a plethora of important compounds. This review summarizes the recent advances in the Oxone-mediated synthesis of N-, O- and chalcogen-containing heterocyclic compounds, through a wide diversity of reactions, starting from several kinds of substrate, highlighting the main synthetic differences, advantages, the scope and limitations.

Synthesis of polycyclic N-heterocyclic compounds via one-pot three-component cyclization strategy

Reported herein is an unprecedented and sequential three-component synthetic strategy for the preparation of polycyclic N-heterocyclic compounds. This synthetic protocol enabled the preparation of a series of novel nitrogen-containing pentacyclic compound under convenient conditions in excellent yields and short reaction time. The synthesized products were characterized by IR, ¹H NMR, ¹³C NMR and mass spectra. Furthermore, the definitive structure of target compounds was confirmed by X-ray analysis.

The microwave-assisted syntheses and applications of non-fused single-nitrogen-containing heterocycles

Microwave technology has emerged as a great tool for the efficient synthesis of organic compounds and it provides opportunities for chemists to achieve chemical transformations that tend to be challenging using classical approaches. Additionally, N-heterocycles are well-known for their medicinal/biological significance, along with their applications as excellent building blocks in chemical synthesis. The dominance of N-heterocycles in drug molecules and other pharmacological agents makes them attractive scaffolds, which encourages chemists to develop a wide range of strategies towards the greener synthesis and functionalization of these heterocycles. In this regard, we have collated and discussed literature relating to the microwave-assisted synthesis and the modification of non-(benzo)fused single-nitrogen-containing N-heterocycles from the past decade. The role of the microwave technique and its benefits over the conventional approach have also been emphasized in terms of overall reaction efficiency, reaction time, yield, reduced side-product generation, neat and clean reactions, chemo-/regio-/enantio-selectivity, and the use of mild reagents/reaction conditions to achieve the objectives of green and sustainable chemistry.

Visible light-mediated intramolecular C–H arylation of diazonium salts of N-(2-aminoaryl)benzoimines: a facile synthesis of 6-arylphenanthridines

6-Arylphenanthridines were synthesized in good to excellent yields from inexpensive and environmentally benign N-(2-aminoaryl)-diphenylmethanimine as a starting material under visible light-photocatalyzed conditions.