An overview of the cycloaddition chemistry of fulvenes and emerging applications

Abstract

The unusual electronic properties and unique reactivity of fulvenes have interested researchers for over a century. The propensity to form dipolar structures at relatively low temperatures and to participate as various components in cycloaddition reactions, often highly selectively, makes them ideal for the synthesis of complex polycyclic carbon scaffolds. As a result, fulvene cycloaddition chemistry has been employed extensively for the synthesis of natural products. More recently, fulvene cycloaddition chemistry has also found application to other areas including materials chemistry and dynamic combinatorial chemistry. This highlight article discusses the unusual properties of fulvenes and their varied cycloaddition chemistry, focussing on applications in organic and natural synthesis, dynamic combinatorial chemistry and materials chemistry, including dynamers, hydrogels and charge transfer complexes. Tables providing comprehensive directories of fulvene cycloaddition chemistry are provided, including fulvene intramolecular and intermolecular cycloadditions complete with reactant partners and their resulting cyclic adducts, which provide a useful reference source for synthetic chemists working with fulvenes and complex polycyclic scaffolds.

Substrate-Controlled Domino Reaction ofN-Sulfonyl Ketimines with 2-Aroyl-1-chlorocyclopropanecarboxylates: Access to Cyclopenta[c]chromenes and Benzo[f]cyclopenta[d][1,2]thiazepine Dioxides

“…To further expand our current methodology, we are highly enthralled in synthesizing pentafulvene-fused-benzo[f ] [1,2]thiazepine dioxide building blocks because the benzo[f ] [1,2]thiazepine dioxide moiety constitutes many privileged scaffolds considered as drug-like molecules [such as a commercial antidepressant drug like Tianeptine, trade names: Stablon, Coaxil, Tatinol]. 22,23 Furthermore, they also displayed remarkable biological activities while acting as HIV protease inhibitors, 24 calcium-sensing receptor agonists, 25 and farnesyltransferase inhibitors.…”

“…8 Keeping in view of their phenomenal importance, massive efforts have been exercised toward the search of efficient routes to access pentafulvene-fused scaffolds. [1][2][3][4][5]9,10 Among them, the fusion of a biologically important chromene moiety 11 with a pentafulvene to afford a cyclopenta-fused-chromene with high molecular complexity is especially a lucrative target for organic and medicinal chemists. These hybrid precursors might bestow advantageous biological actions and even unprecedented properties.…”

Reactivity of [Ce(NR2)3] (R = SiMe3) with Prospective Carbon Atom Transfer Reagents

“…In addition, we have discovered a new synthetic pathway to the highly reactive methylenecyclopropene fragment, which is of interest for its insights into aromaticity, as well as its use as a precursor to spiro-compounds. [51][52][53][54][55] ASSOCIATED CONTENT…”

“…While we were ultimately unsuccessful in our efforts to generate either a cerium carbide or alkylidene complex, this work expands the scope of Ce­(III)-mediated photochemistry, which is an emerging area of photocatalysis. In addition, we have discovered a new synthetic pathway to the highly reactive methylenecyclopropene fragment, which is of interest for its insights into aromaticity, as well as its use as a precursor to spiro compounds. − …”

Palladium-Catalyzed Aminomethylative Oppolzer-Type Cyclization of Enynes: Access to Aminomethylated Benzofulvenes

“…Benzofulvene, as a privileged scaffold, has been widely used in synthetic organic chemistry and polymer chemistry . Over the past decade, a great number of methods have been developed to construct functionalized benzofulvenes .…”