Seven-Membered Rings

One-Step Assembly of Functionalized Morpholinones and 1,4-Oxazepane-3-ones via [3 + 3]- and [3 + 4]-Annulation of Aza-Oxyallyl Cation and Amphoteric Compounds

“…Use of saturated N-heterocycles of different ring sizes has become indispensable in the current paradigm of the drug discovery and development efforts . Their significance and wide utility demand continuous feeding of new synthetic strategies that can address key synthetic challenges such as one-step convergent access to the functionalized core structures including those with the medium-sized ring. − Several groups including Bode, , Aggarwal, and Carreira have sought to identify practicable solutions to the existing shortcomings, and some important advances were made in recent years through development of distinct intermolecular and intramolecular approaches (Scheme a). − Bode’s development of SnAP reagents is particularly noteworthy as it allows one-step generation of a range of functionalized, medium-sized (six to nine membered rings) saturated N-heterocycles.…”

Biocatalytic Access to 1,4-Diazepanes via Imine Reductase-Catalyzed Intramolecular Asymmetric Reductive Amination

“…(R)-2a is the key intermediate of Suvorexant (1), but the catalytic efficiency of IR1 was unsatisfactory. In order to improve the catalytic activity of IR1, enzyme engineering was carried out.…”

“…Chiral seven-membered nitrogen heterocycles have attracted great attention owing to their wide application in the synthesis of natural products and pharmaceuticals. − Among them, chiral 1,4-diazepanes are important structural units with diverse biological properties and pharmaceutical importance, such as Ripasudil, a derivative of Fasudil which is a Rho-associated kinase inhibitor used for treatment of glaucoma and ocular hypertension, , and Suvorexant ( 1 ), a selective, dual-orexin receptor antagonist for treatment of primary insomnia (Scheme ). , Recently, Dai et al developed an intermolecular amphoteric diamination of allenes to access a wide range of racemic 1,4-diazepanes in one step .…”

Metal-free visible light-induced cross-dehydrogenative coupling of benzocyclic imines with water/P(O)H compounds: efficient access to functionalized benzazepines/ones

“…Benzazepines/ones, as one of the most important classes of N-heterocycles, are receiving a great deal of attention in medicinal chemistry and materials science fields because of their pharmacological activity and physico-chemical properties. 1 For example, Sintamil 1 a – c is a well-known antidepressant, while diazepinomicin (TLN-4601) 1 d – e is a typical anticancer drug for K-Ras mutant models in the clinic, and 6-(dibenzo[ b , f ][1,4]thiazepin-11-yl)dibenzo[ c , e ][1,2]oxaphosphinine 6-oxide (BDS-DOPO) is employed as a superior flame retardant 1 f (Scheme 1a). Unfortunately, access to a large number of structural derivatives of these benzazepines/ones is hindered by their multistep syntheses, low environmental friendliness, and low efficiency.…”