Cu(OAc)2-Catalyzed Aerobic Oxidative Dehydrogenation Coupling: Synthesis of Heptacyclic Quinolizino[3,4,5,6-kla]perimidines

Cu(OAc)2-catalyzed three-component cycloaddition of malonates, nitrosoarenes and alkenes: access to isoxazolidines

The Cu(OAc)₂-catalyzed one-pot three-component cycloaddition of malonates, nitrosoarenes and alkenes is described. A wide range of isoxazolidines could be obtained in moderate to excellent yields via this method. Mechanistic investigations indicated that the key step in this catalytic system is the straightforward formation of nitrone intermediates through the Cu(OAc)₂-catalyzed reaction of malonates with nitrosoarenes.

Copper acetate catalysed C-C bond formation en route to the synthesis of spiro indanedione cyclopropylpyrazolones

This article reports the synthesis of spiro compounds based on an indanedione-cyclopropane-pyrazolone framework. The reaction relied upon the Michael-initiated ring closure strategy and was carried out under Cu(OAc)₂ catalysis, assisted by an oxygen atmosphere and the base Et₃N. The final compounds were obtained as an inseparable mixture in most cases with modest to good yields using diverse substrates. Among the two plausible routes, computational studies indicated the feasibility of a route which involves a four-membered Cu containing intermediate. Given the generic nature of the developed method, it may be utilised to synthesise other analogous spiro systems.

Recent Advances in Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds

This review surveys recent progress in the chemistry of polycyclic heteroaromatic molecules with a focus on structural diversity and synthetic methodology. The article covers literature published during the period of 2016-2020, providing an update to our first review of this topic (Chem. Rev. 2017, 117 (4), 3479-3716).

Cu(OAc)2 catalysed aerobic oxidation of aldehydes to nitriles under ligand-free conditions

An economically efficient ligand-free oxidative conversion of aldehydes to nitriles has been achieved using Cu(OAc)2 and NH4OAc as inexpensive materials of low toxicity in the presence of aerial oxygen as an eco-friendly oxidant.

Cu(II)-Mediated aerobic oxidative synthesis of 2-sulfonylated chromeno[4,3-c]pyrazol-4(2H)-ones

Herein, a concise and facial synthesis of 2-sulfonylated chromeno [4,3-c]pyrazol-4(2H)-ones and 2,5-dihydro-4H-pyrazolo[4,3-c]quinolin-4-ones via a Cu(II)-promoted aerobic oxidative cascade C–C/C–N bonds formations was described. The protocol has advantages of atom economy,...

Perimidines: a unique π-amphoteric heteroaromatic system

Data on the physicochemical characteristics, theoretical calculations, reactivity and synthetic methods for perimidines are summarized. Although perimidine and some of its simple 2-substituted derivatives were obtained by Sachs back in 1909, their chemistry and key physical properties remained unknown until the early 1970s. Subsequent studies revealed many fundamental features of the perimidine system, previously not encountered in the heterocyclic series. The first comprehensive review on perimidines was published forty years ago. The period that has passed since 1980 led to the emergence of new directions and trends. Several hundred new publications have appeared, the generalization of which has become the main purpose of this article. This primarily concerns the obtaining of highly nucleophilic and stable perimidine carbenes, new methods of electrophilic substitution and oxidation, establishment of a close relationship between perimidines and proton sponges, and modern theoretical calculations. Based on perimidines, many different polycondensed systems have been obtained. Applied research has developed especially rapidly in recent years. Many new compounds based on perimidines related to chemosensors, analytical reagents, dyes, metal catalysts, electronic devices, nanotechnology, and medical chemistry have been proposed. Some information under review is presented as Supplementary Materials. It contains six tables, which include data on the basicity constants of perimidines, details of some synthetic methods for perimidines and fused analogs and also a list of biological activities of perimidines.

The bibliography includes 387 references.

Recent Advances in the Synthesis of Perimidines and their Applications

Perimidines are versatile scaffolds and a fascinating class of N-heterocycles that have evolved significantly in recent years due to their immense applications in life sciences, medical sciences, and industrial chemistry. Their ability of molecular interaction with different proteins, complex formation with metals, and distinct behavior in various ranges of light makes them more appealing and challenging for future scientists. Various novel technologies have been developed for the selective synthesis of perimidines and their conjugated derivatives. These methods extend to the preparation of different bioactive and industrially applicable molecules. This review aims to present the most recent advancements in perimidine synthesis under varied conditions like MW radiation, ultrasound, and grinding using different catalysts such as ionic liquids, acid, metal, and nanocatalyst and also under green environments like catalyst and solvent-free synthesis. The applications of perimidine derivatives in drug discovery, polymer chemistry, photo sensors, dye industries, and catalytic activity in organic synthesis are discussed in this survey. This article is expected to be a systematic, authoritative, and critical review on the chemistry of perimidines that compiles most of the state-of-art innovation in this area.

An efficient synthesis of 16H-dibenzo[2,3:6,7][1,4]oxazepino[5,4-b]quinazolin-16-ones via an Ullmann reaction catalyzed by CuI

CuI functions as a mild Lewis acid catalyst to promote the condensation and cyclization reaction of 2-amino-N-(2-hydroxyphenyl)benzamide and 2-bromobenzaldehyde to build the quinazoline moiety first. With the addition of Cs₂CO₃, it also can catalyse the subsequent intramolecular Ullmann type reaction to give 16H-dibenzo[2,3:6,7][1,4]oxazepino[5,4-b]quinazolin-16-ones in good yields.

Dioxane-involving reaction for the synthesis of 3-aryl-1-(2-(vinyloxy)ethoxy)isoquinolines catalyzed by AgOTf

Dioxane was found to be involved in the reaction of 2-(arylethynyl)benzaldehydes and 3-aminopyrazine-2-carbohydrazide, and underwent a ring-opening reaction catalyzed by AgOTf. This domino type procedure provided an efficient method for the synthesis of 3-aryl-1-(2-(vinyloxy)ethoxy)isoquinolines in good yields via the loss of a molecule of 3-aminopyrazine-2-carboxamide.

Synthesis of Substituted 4 H-Thiochromen-4-imines via Copper-Catalyzed Cyclization Cascades of o-Bromobenzothioamides with Terminal Alkynes

A series of ( E)- N-aryl-4 H-thiochromen-4-imines has been conveniently obtained through a cascade reaction between o-bromobenzothioamides and terminal alkynes. This novel approach probably involved an initial generation of benzothietane-2-imine intermidates via an intramolecular Ullmann reaction under CuI/L-proline cocatalysis and alkaline conditions followed by imine alkynylation, ring opening, and cyclization sequences to provide the unexpected 4 H-thiochromen-4-imines rather than isothiochromans.

An efficient synthesis of 6-arylbenzo[4,5]imidazo[2,1-a]isoquinolines via sequential α-arylation of carbonyl and deacylation catalyzed by CuI

Dibenzoyl methane was found to undergo α-arylation of carbonyl and deacylation reaction with 2-(2-bromophenyl)-1H-benzo[d]imidazoles catalyzed by CuI in the presence of Cs₂CO₃, and provided an efficient synthesis of 6-arylbenzo[4,5]imidazo[2,1-a]isoquinolines.