The Oxygen-Containing Fused Heterocyclic Compounds

Abstract

The oxygen-containing heterocycles are an important class of compounds in organic chemistry. These compounds are used as drugs (coumarin and oxazole), solvent (tetrahydrofuran), flavors, and fragrances (lactones). The fusion of aromatic ring to the oxygen-heterocycle will change the electron density; thereby, the physical/chemical/biological properties will alter. Also, the preparation of these fused molecules will require a different strategy/method/reaction condition. The topics covered in this chapter are the general synthetic methods and uses of fused heterocyclic compounds containing oxygen as a heteroatom. The derivatization of the primary scaffold is excluded from this chapter. Some of the fused compounds are coumarin (benzopyrans) and piclozotan (benzoxazepines).

A Comprehensive Account of Synthesis and Biological Activities of α‐lidene‐ Benzocycloalkanones and Benzoheterocycles

“…Wang et al carried out gold-catalyzed rearrangement of [3,3]propargyl ester, proceeded by Michael addition which gave (E)-1H-inden-1-one. When AuCl, AuCl 3, and PPh 3 AuCl were used in nitromethane at room temperature for 24 h, it was discovered that no reaction had occurred (Scheme 5).…”

“…When AuCl, AuCl 3, and PPh 3 AuCl were used in nitromethane at room temperature for 24 h, it was discovered that no reaction had occurred (Scheme 5). [11] Remarkably, after 15 minutes of using 5 mol% PPh 3 AuCl/AgOTf in nitromethane at room temperature, the predicted tandem [3,3]-propargyl ester rearrangement occurred, giving 15 in good yield. AgOTf addition served as a chloride scavenger and affected the gold cation's reactivity.…”

“…al, other tactics are used to synthesize 9-membered carbocycles to observe carbocyclic ring conformations in the system's efforts to reduce the angle and torsional strain. [2] Due to their natural abundance and diverse variety of biological roles, heterocycles like oxygen [3,4] and nitrogen are also crucial molecules in organic chemistry in addition to carbocycles. As examples of specific medications to treat cancer, taxol, dasatinib, and other naturally occurring and semisynthetic oxygen and heterocyclic nitrogen compounds are listed.…”

“…As examples of specific medications to treat cancer, taxol, dasatinib, and other naturally occurring and semisynthetic oxygen and heterocyclic nitrogen compounds are listed. Researchers have worked hard for the past 20 years to develop innovative sp 3 -enriched 3D building blocks that can be used as commercial sources to create molecules with significant therapeutic value. Since 1984, benzofurano, benzopyrano, and indolin-3-one have been reported in the literature as biologically active chemicals with target selectivity.…”

Marine cuttlefish derived 2 H ‐benzochromenone: Pharachromenone as a dual inhibitor of pro‐inflammatory 5‐lipoxygenase and cyclooxygenase‐2

“…Recently, oxygen‐containing heterocycles, such as coumarin, oxazole, and macrocyclic lactones, are the preferred choices for use as functional food components and pharmacophore agents. Conspicuously, the fusion of the aromatic ring to the oxygen‐heterocycle would enhance the electron density and thereby improving the chemical and biologic properties (Venkatachalam & Kumar, 2019). Substituted chromene and benzochromene derivatives are considered as preferential oxygenated heterocyclics, which were emerged as critical structural motifs against various disease targets and possess a wide range of useful pharmacological activities (Thomas & Zachariah, 2013).…”