Molecular Acrobatics in Polycyclic Frames: Synthesis of Functionalized D₃-Trishomocubanes via the Rearrangement Approach

Abstract

A new synthetic route to D-trishomocubanone and oxa- D-trishomocubane derivatives has been established by the rearrangement approach. A remotely located methyl substituent in the six-membered ring contributed to the acid-catalyzed rearrangement of the cage dione in an unusual fashion. This rearrangement approach provided an attractive route to extended D-trishomocubanes, which are not accessible by the conventional multistep synthetic sequence. For the first time, two phenyl groups were incorporated from the solvent into the strained trishomocubane skeleton in an unprecedented manner via carbocation-mediated rearrangement with the aid of BF·OEt. Interestingly, an oxa-bridged trishomocubane skeleton was also formed during acid-promoted rearrangement.

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

“…[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.…”

“…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.…”

Late‐stage Modification of Cage Diones by Tandem Metathesis

“…(4 b,8 a) 2 a,2a1,3,4,4 a,5,4,1,2]triyl)-5,8-methanobenzo [1,4]cyclobuta [1,2,3-cd]pentalene-1,10-dione (18). White crystalline solid, R f = 0.54 (1.5 : 8.5 EtOAc/petroleum ether).…”

“…The intrinsic strain and rigid framework associated with cage scaffolds make them suitable systems to undergo interesting rearrangements to deliver novel products. [2] During the last four decades, several groups explored simple PCUD and its derivatives in different domains, such as pharmaceutical and medicinal chemistry, [3] high energy density materials (HEDMs), [4] polymer science [5] and supramolecular chemistry. [6] Among cage molecules, adamantane derivatives are used as drug candidates.…”

Synthesis and Acid Catalyzed Rearrangement of Cage Propellanes

“…Recently, we have demonstrated a new synthetic approach to D 3 ‐trishomocubane derivatives via acid‐catalyzed rearrangement starting with cage [4.4.2] and [4.3.2]propellane derivatives 2 , 3 , and 6 –. Our aim in this area is to expand the propellane frameworks by rearrangement strategies starting with various functionalized cage diones .…”