The divergent catalytic reaction provides quick access to structurally diversified compounds from a common precursor via controlled reaction pathway, and is highly attractive tool in discovery of drugs and functional materials.1 In light of our interest in the use of transient palladium intermediates for divergent palladium catalysis, we recently reported a novel tandem divergent catalytic method that allow formation of four different aromatic scaffolds from nitriles (Eq. a).2 Along this line, we have investigated a tandem divergent C(sp3)-H activation of the common transient σ-alkylPd(II)-intermediate, formed by carbopalladation of N-allylated 2-bromoarylamines. Here we present our finding that the amine α-C(sp3)-H or 1° and 2° alkyl C(sp3)-H could selectively activated simply by choice of palladium/lignad and solvent to deliver the fused- or spiro-cyclopropanated indolines, or protonative and alkynylative trapping products (Eq. b).3
1) A Review on the catalyst-controlled reactions, see: J. Mahatthananchai, Dumas, A. M.; Bode, J. W. Angew. Chem. Int. Ed. 2012, 51, 10954.
2) Kim, J. H.; Bouffard, J.; Lee, S.-g. Angew. Chem. Int. Ed. 2014, 53, 6435-6438 (Highlighted in SYNFACT)
3) Lee, J.-s.; Lee, W. K.; Lee, S.-g. manuscript in preparation.