Ring-Closing Metathesis Approach to Cage Propellanes Containing Oxepane and Tetrahydrofuran Hybrid System

Abstract

The preparation of a variety of structurally interesting oxygenated cage compounds involving atom-economic processes such as Claisen rearrangement, Diels–Alder reaction, [2+2] photocycloaddition, and ring-closing metathesis (RCM) as key steps is reported. For the first time, oxepane ring system is introduced in cage framework using olefin metathesis as a key step. These cage systems assembled here are difficult to prepare by traditional methods. The synthetic sequence described here opens up new routes to higher order polycycles containing heteroatoms without the involvement of protecting groups. Transannular cyclization observed during Grignard addition and the RCM protocol used here may be applicable to generate unknown oxygenated cage systems.

Pentacycloundecane (PCUD)‐Based Cage Frameworks as Potential Energetic Materials: Syntheses and Characterization

“…Recently, some efforts have been directed in developing new strategies to design various interesting and unusual polycyclic cage compounds via RCM and rearrangement approaches [67–70] . The present work is aimed at gaining a detailed insight into the chemistry of PCUD‐derived energetic cage compounds along with their synthetic protocols.…”

“…[16] Recently, some efforts have been directed in developing new strategies to design various interesting and unusual polycyclic cage compounds via RCM and rearrangement approaches. [67][68][69][70] The present work is aimed at gaining a detailed insight into the chemistry of PCUD-derived energetic cage compounds along with their synthetic protocols. In continuation of an effort to expand the chemical space of cage compounds, our efforts have been diverted to study the energetic properties of high nitrogen cage frameworks using Diels-Alder (DA) chemistry [71] and [2 + 2] photocycloaddition [72] as the key steps.…”

Realization of Photo‐Thermal Metathesis Under Microwave Irradiation Conditions: An Entry to Triquinane Frameworks

“…Similarly, diallyl spiro cage dione 30 was subjected to the photo‐thermal metathesis under MWI conditions (150 W, 220 °C, 30 min) in DPE produced the corresponding diallyl triquinane derivative 31 (29%) along with a double bond isomerized product 32 in 47% yield (Table ).…”

Design and Synthesis of Polycycles, Heterocycles, and Macrocycles via Strategic Utilization of Ring‐Closing Metathesis

“…We also envisioned a useful method for the construction of annulated cage heterocycle 228 by employing RCM as a key step . In this regard, treatment of the dione 222 with allyl Grignard reagent delivered the triallyl hemiketal 225 along with the tetraallyl diol 223 .…”