Free-Radical Carbocyanation of Cyclopropenes: Stereocontrolled Access to All-Carbon Quaternary Stereocenters in Acyclic Systems

Abstract

Free-radical carbocyanation of cyclopropenes offers straightforward access to tetrasubstituted cyclopropanes in satisfying yields with moderate diastereoselectivity. The incorporation of various functional groups on the cyclopropane ring allows a subsequent base-mediated ring-opening reaction leading to functionalized acyclic systems having an all-carbon quaternary stereocenter.

Free‐Radical Carbocyanation of Olefins

“…Various reports have also described the use of sulfonylc yanides as efficient cyanating agents in radicalp rocesses, [11] on the consecutive incorporation of ac arbon fragment and ac yano substituent on an olefinic backbone. [13] Optimizationo ft he process also led us to developat in-free (two-component) version of this carbocyanation using ar eadily available sulfonyl cyanide incorporating both functional groupst obea dded to the olefin. [13] Optimizationo ft he process also led us to developat in-free (two-component) version of this carbocyanation using ar eadily available sulfonyl cyanide incorporating both functional groupst obea dded to the olefin.…”

“…On the basis of previous work on carbo‐azidation, carbo‐alkenylation,, and carbo‐oximation,, we describe herein an efficient three‐component free‐radical carbocyanation of electron‐rich olefins . Optimization of the process also led us to develop a tin‐free (two‐component) version of this carbocyanation using a readily available sulfonyl cyanide incorporating both functional groups to be added to the olefin.…”

Recent Developments in Radical‐Mediated Transformations of Organohalides

“…Later on, not only xanthate, bromine atom transfer processes were also reported by the researchers . Continuation of their interest in recent studies, Landais group described the visible light mediated addition of phenacyl bromides with cyclopropenes using iridium photocatalyst to rendered the naphthalenones with acceptable yields under conventional reaction conditions (Scheme ) …”

Synthetic Applications of Cyclopropene and Cyclopropenone: Recent Progress and Developments

“…[10] Those frameworks are very much important due to their diverse biological applications. [68] The 1,3-dipolar cycloaddition reactions of azomethine ylides with alkene is an efficient methodology for regio-and stereoselective synthesis of structurally complex spirocyclic heterocycles. [69] The reaction of highly substituted cyclopropene with azomethine ylides generated from aziridines was reported by Lown and Uchida.…”