Search for "unprotected 3-substituted oxindoles" in Full Text gives 2 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218
Beilstein J. Org. Chem. 2012, 8, 1360–1365, doi:10.3762/bjoc.8.157