Corrigendum to solvent-dependent oxidative coupling of 1-aryl-1,3-dicarbonyls and styrene

Abstract

This report describes the scope and mechanism of the solvent-dependent, chemoselective oxidative coupling of 1-aryl-1,3-dicarbonyls with styrene using Ce(IV) reagents. Dihydrofuran derivatives are obtained when reactions are performed in methanol whereas nitrate esters can be selectively synthesized in acetonitrile and methylene chloride. Mechanistic studies are consistent with the rate of solvent-assisted deprotonation of a radical cation intermediate playing an integral role in the selective formation of products.

Reaction mechanisms: radical and radical ion reactions

“…Flowers et al explored the surprising solvent-dependent chemoselectivity of CAN-induced oxidative couplings of dicarbonyl compounds with styrene (Scheme 10 illustrates a typical example). 25 Thus, when the reaction is performed in methanol, the dihydrofuran derivative 43 is the major product, whereas nitrate 42 is predominantly formed in acetonitrile. This can be rationalized by a mechanism where the initially formed distonic radical cation 44 undergoes a solvent-assisted deprotonation in methanol, whereas in acetonitrile the proton remains bound to the 1,3-dicarbonyl moiety to cause a rigid 6-membered ring complex.…”