Organocatalytic atroposelective fluorooxindole addition to coumarin Michael acceptors†
Abstract
Organocatalytic atropisomeric synthesis with fluorinated oxindoles and 4-halo-3-nitrocoumarins gives congested structures displaying a Csp2–Csp3 chirality axis and an adjacent tetrasubstituted stereogenic carbon center with good yields, up to 97% ee and 41 : 1 dr. The scalable dehalogenative C–C bond formation is achieved under mild conditions with a commercially available urea catalyst.