A Highly Pyramidalized Cage Alkene Formed via the Double Diels−Alder Cycloaddition of syn-4,5,13,14-Bis(dehydro)octafluoroparacyclophane to Anthracene

Abstract

[reaction: see text] A double Diels-Alder reaction of the formal syn-bis(dehydro)octafluoroparacyclophane with anthracene leads to formation of a novel cage compound that contains a highly pyramidal double bond. The measures of pyramidality of this double bond constitute what appear to be the highest combined values of psi and phi (34.3 degrees and 33.5 degrees, respectively) yet reported to have been determined by X-ray crystallography. This cage compound, although stable indefinitely as a crystalline compound in air, exhibits the high reactivity with both triplet and singlet O2 in solution that is characteristic of such highly pyramidal pi systems.

Development and Applications of Double Diels‐Alder Reaction in Organic Synthesis

“…In 2005, one of the unique applications of DDA reaction was introduced by Dolbier, et al. where they reported the synthesis of novel cage compounds containing highly pyramidal double bonds skeleton [56] . These cage compounds are found to be stable in spite of varying ring strain and exhibited unique reactivity with singlet and triplet oxygen.…”

“…Considering difluoro derivatives of paracyclophanes as a potential substrate for Diels‐Alder reaction, t ‐BuOK catalyzed treatment of syn ‐bis(dehydro)octafluoroparacyclophanes 29 with anthracene 30 underwent distinctive DDA reaction to afford novel cage compound 32 via intermediate anthracene adduct 31 with ease in moderate yield (see Scheme 6). Further, commitments regarding structure confirmation of cage compounds were thoroughly studies by same group and utilized developed approach to access such several novel scaffolds in limited number of steps [56] …”

“…In 2005, one of the unique applications of DDA reaction was introduced by Dolbier, et al where they reported the synthesis of novel cage compounds containing highly pyramidal double bonds skeleton. [56] These cage compounds are found to be stable in spite of varying ring strain and exhibited unique reactivity with singlet and triplet oxygen. Considering difluoro derivatives of paracyclophanes as a potential substrate for Diels-Alder reaction, t-BuOK catalyzed treatment of syn-bis (dehydro)octafluoroparacyclophanes 29 with anthracene 30 underwent distinctive DDA reaction to afford novel cage compound 32 via intermediate anthracene adduct 31 with ease in moderate yield (see Scheme 6).…”

“…Further, commitments regarding structure confirmation of cage compounds were thoroughly studies by same group and utilized developed approach to access such several novel scaffolds in limited number of steps. [56] First ever report on kinetics and thermodynamics study by Woodward and Baer in 1948 made a significant impact on DDA studies employed for various scaffolds. [57] In line, Borisova et al in 2018, reported a rare chemo-specific tandem Diels-Alder reaction of activated alkynes (DMAD derivatives) and bis-diene 33 (see Scheme 7).…”

Synthesis ofgem-Difluoromethylenated Polycyclic Cage Compounds

“…We have recently reported the synthetic utilities of PhSCF 2 SiMe 3 ( 1 ) as a useful gem -difluoromethylene building block for the syntheses of gem -difluoromethylenated 1-azabicyclic compounds, , spiro-γ-butyrolactones, macrocyclic lactones, and cyclopentanols and as a difluoromethylating agent for the syntheses of difluoromethylketones, , γ-difluoromethyl-γ-lactams, and bicyclic ketones . The present work focuses on the synthesis of gem -difluoromethylenated polycyclic cage compounds, and to the best of our knowledge, the fluorinated cage compounds have rarely been reported in the literature . Carbocyclic and heterocyclic cage compounds (Figure ) have attracted particular attention from several research groups due to the challenges in their syntheses and for their chemical as well as biological activities. , Their unique properties and chemical reactivities are associated with the rigid and highly compact structural frameworks.…”