Iodine(III)-catalyzed rearrangements of imides: a versatile route to α,α-dialkylated α-hydroxy carboxylamides

Abstract

A tertiary hydroxy group α to a carboxyl moiety comprises a key structural motif in many bioactive substances. With the herein presented metal-free rearrangement of imides triggered by hypervalent λ(3)-iodane, an easy and selective way to gain access to such a compound class, namely α,α-disubstituted-α-hydroxy carboxylamides, was established. Their additional methylene bromide side chain constitutes a useful handle for rapid diversification, as demonstrated by a series of further functionalizations. Moreover, the in situ formation of an iodine(III) species under the reaction conditions was proven. Our findings clearly corroborate that hypervalent λ(3)-benziodoxolones are involved in these organocatalytic reactions.

Keywords: hypervalent compounds; imides; iodine; rearrangements; α-hydroxy carboxylamides.