N,N-Diisopropylformamidine (DIFA) Protection of Anilines in Metalation Reactions

Abstract

A novel N,N-diisopropylformamidine (DIFA) protecting group for anilines was studied. Metalation is often metal-directed by this weakly coordinating and bulky group, making it complementary to ortho-metalation directed by tert-butylcarbamate and pivaloylamide groups and to regular electrophilic reactions of anilines. Importantly, DIFA is removed under nucleophilic conditions and is stable toward acids, thus being orthogonal to tert-butylcarbamate, N-tert-butylamide, and other acid-labile protecting groups.

protecting groups - regioselectivity - metalation - form­amidine

References and Notes

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