Suppressing the Anionic Fries Rearrangement of Aryl Dialkylcarbamates; the Isolation of a Crystalline <i>ortho</i>‐Deprotonated Carbamate

Abstract

Abstract In the presence of organolithium bases phenyl dialkylcarbamates have previously been shown to undergo facile rearrangement to yield the corresponding salicylamides. However, heterometallic lithium diethyl(2,2,6,6‐tetramethylpiperidido)zincate achieves the clean directed ortho ‐metallation (DoM) of phenyl dialkylcarbamates, with [C 6 H 4 {OC(O)NMe 2 }{Zn(‐TMP)Et}Li] 2 having been structurally characterized. DFT studies point to a stepwise deprotonative mechanism in which the zincate reagent exhibits kinetic amido basicity. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2008)