Anti-selective [3+2] (Hetero)annulation of non-conjugated alkenes via directed nucleopalladation

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Abstract 2,3-Dihydrobenzofurans and indolines are common substructures in medicines and natural products. Herein, we describe a method that enables direct access to these core structures from non-conjugated alkenyl amides and ortho -iodoanilines/phenols. Under palladium(II) catalysis this [3 + 2] heteroannulation proceeds in an anti -selective fashion and tolerates a wide variety of functional groups. N -Acetyl, -tosyl, and -alkyl substituted ortho -iodoanilines, as well as free –NH 2 variants, are all effective. Preliminary results with carbon-based coupling partners also demonstrate the viability of forming indane core structures using this approach. Experimental and computational studies on reactions with phenols support a mechanism involving turnover-limiting, endergonic directed oxypalladation, followed by intramolecular oxidative addition and reductive elimination.