Efficient Two-Step Synthesis of Salicylaldehydes via Directed ortho-Lithiation of in situ N-Silylated O-Aryl N-Isopropylcarbamates

Abstract

O-Aryl N-isopropylcarbamates, conveniently prepared from phenols and isopropyl isocyanate, are subjected to an efficient ortho-lithiation protocol to afford the corresponding salicylaldehydes in a one-pot operation in high yields.

Key words

carbanions - formylation - lithiation - phenols - salicylaldehydes

References

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19

Carbamate 1d can either be obtained by ortho-lithiation [8b] or by reaction of 2-(trimethylsilyl)phenol with isopropyl isocyanate (96%).