A Review on Synthesis, Reactions and Biological Properties of Seven Membered Heterocyclic Compounds: Azepine, Azepane, Azepinone

Abstract

Seven membered heterocyclic Azepine and its derivatives have great pharmacological and therapeutic implications. In this review, the literature of the last fifty years has been exploited for the synthesis, reaction, and biological properties of these seven-member heterocyclic compounds. Most of the mechanisms involved the ring expansion of either five or six-membered compounds using various methods such as thermally, photo-chemically, and microwave irradiation. The systematically designed schemes involve the synthesis of different derivatives of azepine, azepinone, azepane, etc. using similar moieties by the different researchers. However, there is much work yet to be done in the biological section, as it is not explored and reported in the literature; therefore, N-containing seven-membered heterocycles still have much scope for the researchers.

Asymmetric hydrogenation of dibenzo-fused azepines with chiral cationic ruthenium diamine catalysts

“…1). 3 To date, considerable protocols have been reported for the asymmetric synthesis of these optical pure skeletons, 1,4 including an asymmetric tandem allylic vinylation/amination reaction, 5a enantioselective addition of organometallic reagents, 5b alkynylation, 5c Mannich addition, 5d,e aza-Reformatsky reactions to the dibenzo-fused azepines, 5f and so on. Among them, the catalytic asymmetric hydrogenation of corresponding dibenzo-fused azepines represents one of the most prominent approaches to obtain such chiral molecules.…”

“…Among them, the catalytic asymmetric hydrogenation of corresponding dibenzo-fused azepines represents one of the most prominent approaches to obtain such chiral molecules. 4,6 In 2011, Zhou and co-workers reported that the iridium diphosphine complexes are efficient catalysts for the asymmetric hydrogenation of dibenzo[b, f ] [1,4]-oxazepines (up to 94% ee) in the presence of morpholine-HCl, 7a and later on, a similar chiral iridium catalyst was applied to the asymmetric hydrogenation of dibenzo[b, f ] [1,4]-thiazepines (up to 96% ee) in the presence of iodine (Scheme 1a). 7b In 2013, Pd complexes of chiral diphosphines proved to be effective catalysts for the asymmetric hydrogenation of dibenzo[b, f ] [1,4]-thiazepines (up to 94% ee) with the addition of a Brønsted acid.…”

“…4,6 In 2011, Zhou and co-workers reported that the iridium diphosphine complexes are efficient catalysts for the asymmetric hydrogenation of dibenzo[b, f ] [1,4]-oxazepines (up to 94% ee) in the presence of morpholine-HCl, 7a and later on, a similar chiral iridium catalyst was applied to the asymmetric hydrogenation of dibenzo[b, f ] [1,4]-thiazepines (up to 96% ee) in the presence of iodine (Scheme 1a). 7b In 2013, Pd complexes of chiral diphosphines proved to be effective catalysts for the asymmetric hydrogenation of dibenzo[b, f ] [1,4]-thiazepines (up to 94% ee) with the addition of a Brønsted acid. 8 Recently, the group of Vidal-Ferran demonstrated that iridium complexes of chiral phosphine-phosphites efficiently catalyzed the asymmetric hydrogenation of diverse dibenzo-fused azepines (X = O, S, CH 2 , SO 2 ), 9 but excellent enantioselectivities were obtained only for specific substrates.…”

“…Intrigued by these results, we hope to further apply this catalytic system to other dibenzofused azepines. Recently, the Bhanage group reported the asymmetric transfer hydrogenation of dibenzo[b, f ] [1,4]oxazepines with up to 93% ee by using a chiral Ru/diamine catalyst (Scheme 1b). 14 with excellent isolated yields and enantioselectivities (up to 99% ee) (Scheme 1c).…”

Enantioselective Formal [4 + 3] Annulations to Access Benzodiazepinones and Benzoxazepinones via NHC/Ir/Urea Catalysis

“…Both 1,4-benzodiazepine and 1,4-benzoxazepine scaffolds containing fused heterocycles are ubiquitous in natural products, bioactive molecules, and pharmaceuticals (Scheme a) . Indeed, several of these seven-membered heterocycles have been identified as selective inhibitors of mitochondrial F 1 F 0 ATP hydrolase ( I ), as well as antihistaminic and antianaphylactic agents (tarpane, II ) .…”