Recent Progresses towards the Strengthening of Cyclopropene Chemistry

Abstract

This short review focuses on the most relevant achievements in the field of cyclopropene chemistry including their syntheses, reactivities, and applications. As the chemistry of cyclopropenes has rapidly evolved in the last few years, valuable implementations on synthetic approaches are nowadays available. Moreover, exciting and useful applications by means of cyclopropenes in organic synthesis and other research areas have also been disclosed. Herein, an overview covering advances accomplished from 2011 until the beginning of 2016 is presented. 1 Introduction 2 Progress on Cyclopropene Syntheses 3 Reactivity of Cyclopropenes 3.1 Carbometalations and Related Reactions 3.2 Cycloisomerizations to Furan Derivatives and Related Reactions 3.3 Cyclopropene Isomerization to Vinyl Carbene Intermediates 3.4 Miscellanea of Reactions 4 Applications of Cyclopropenes 5 Conclusion Key words catalysis, cyclopropenes, cyclopropanes, ring strain, synthesis Rubén Vicente studied chemistry at the Complutense University in Madrid. He obtained his Ph.D. from the University of Oviedo in 2006 with Prof. J. Barluenga, developing synthetic applications of Fischer carbenes. After short research stays at the University of Bonn and Boston College, he spent three years as a Postdoctoral Researcher sponsored by the Humboldt Foundation in the group of Prof. L. Ackermann (Georg-August-Universität, Göttingen, 2007-2009), working on C-H bond functionalizations. He returned to Oviedo in 2010 within the 'Juan de la Cierva' program and since 2012 he has held a 'Ramón y Cajal' Fellowship. In 2014, he was awarded with the Young Investigator Award from the Spanish Royal Chemical Society. His interests include the discovery of new reactivity patterns and sustainable catalysis.

Metal-Dependent Umpolung Reactivity of Carbenes Derived from Cyclopropenes

“…As an alternative strategy, non-diazo carbene precursors have attracted considerable interest over the last decades (Jia and Ma, 2016, Ma et al., 2016, Wang and Wang, 2019). Cyclopropene, a reliable and easy-to-handle precursor, could generate vinyl carbene in a safe, mild, and practical way with a 100% atom economy via transition metal-catalyzed ring-opening rearrangement (Rubin et al., 2007, Archambeau et al., 2015, Vicente, 2016, Benitez et al., 2009). Furthermore, the unique vinyl functionality could offer new opportunities to discover new transformations.…”

Synthesis of 1,2-divinylcyclopropanes by metal-catalyzed cyclopropanation of 1,3-dienes with cyclopropenes as vinyl carbene precursors

“…Consequently, the use of alternative vinyl carbene precursors is highly desirable to expand the accessibility to 1,2-divinylcyclopropanes [17–19]. In this regard, cyclopropenes have demonstrated to be suitable precursors of metal–vinyl carbenes [20–21], which can be easily trapped with alkenes [22–25]. Our recent studies showed that simple ZnCl 2 could be used to generate the corresponding zinc–vinyl carbene to efficiently prepare vinylcyclopropane derivatives with a remarkable broad scope (Scheme 1) [26].…”

Desymmetrization of Cyclopropenes via the Potassium-Templated Diastereoselective 7-exo-trig Cycloaddition of Tethered Amino Alcohols toward Enantiopure Cyclopropane-Fused Oxazepanones with Antimycobacterial Activity

“…Advances in base-assisted additions of heteroatom-based nucleophiles to cyclopropenes made available novel stereo-defined cyclopropyl scaffolds, 1 possessing oxygen, 2 nitrogen, 3 sulfur, 4 or halogen 5 entities, that complement transition-metal-catalyzed cyclopropanation methodologies. 6,7 Both intermolecular (Scheme 1, eq 1) and intramolecular (Scheme 1, eq 2) addition of tethered nucleophiles, employing carbon- 8 or oxygen-based species, has been reported.…”