Synthesis of Benzothiophene‐Fused Oxa[6.6.5]tricyclic Skeletons through a Cinchonidine‐ or NaOH‐Promoted Quadruple Domino Sequence

Abstract

Two base‐promoted quadruple domino reactions between thioaurones and allylic phosphonium salts have been developed to synthesize benzothiophene‐fused oxa[6.6.5]tricyclic skeletons in moderate to good yields with excellent stereoselectivity and broad functional‐group tolerance. This is a simple and useful protocol for the rapid construction of the umbrella‐like oxa[6.6.5]tricyclic skeleton.

Construction of Eight-Membered Cyclic Diaryl Sulfides via Domino Reaction of Arynes with Thioaurone Analogues and DFT Study on the Reaction Mechanism

“…These reactions enabled the synthesis of complex sulfur compounds, which might be hard to synthesize via other methods. On the basis of this background, we envisioned that the reaction of thioaurone derivatives and arynes would be an attractive approach to obtaining eight-membered and bicyclic sulfides via [3 + 2] cycloadditions and the C­(Sp 2 )–S bond cleavage procedure (Scheme ).…”

Construction of [6-5-5-6-6] Pentacyclic Skeleton via a Phosphine-Catalyzed Domino Reaction and Mechanism Study

“…A combination of privileged frameworks is a powerful way to improve molecular diversity and thus discover novel biological properties . Therefore, efficient construction of polyheterocyclic skeletons from readily available starting materials in a minimum number of steps is a highly desired but challenging theme in organic synthesis. − One of the ways to fulfill this goal is the development and use of domino processes, which allow the sequential construction of several bonds by a single-step manipulation. − During our ongoing investigation of domino reactions of thioaurones, − we are interested in the effect on the reaction mode of replacing a substrate oxygen atom with a sulfur atom. Due to the different atomic properties, the sulfur atom may play a different role in controlling the reactivity/selectivity as compared to the oxygen atom.…”

Catalyst- and Additive-Free Approach to Constructing Benzo-oxazine, Benzo-oxazepine, and Benzo-oxazocine: O Atom Transfer and C═O, C–N, and C–O Bond Formation at Room Temperature

“…In particular, a variety of efficient strategies have been recently developed for the construction of N- and O-containing heterocycles such as benzo-oxazine, , benzo-oxazepine, and benzo-oxazocine . The new variants of these heterocycles have continued to emerge; their biological activity has made them a focus of medicinal chemistry over the years …”