Transition‐Metal‐Free α‐C‐Alkylation of Oxindoles with Alcohols

Transition‐metal‐free α‐C‐alkylation of oxindoles with alcohols was performed. The reaction requires the presence of LiOtBu and proceeds under thermal conditions. The method exhibits a wide scope of substrates. Both primary and secondary aliphatic and aromatic alcohols can be employed as the alkylating reagents. Oxindole and various 1‐alkyl‐ or 1‐aryl‐substituted oxindoles can be alkylated. The mechanistic studies show that the reaction may involve both free radical and aldol condensation/MPV processes. Transition‐metal‐free reaction of oxindoles with primary or secondary alcohols in the presence of LiOtBu affords α‐C‐alkylated oxindoles.