Stereospecific and stereoconvergent nucleophilic substitution reactions at tertiary carbon centers

Summary Nucleophilic substitutions such as SN1 and SN2 are fundamental textbook reactions. Their stereoselective versions have been shown to be versatile in the preparation of enantiopure compounds. In this review, we discuss challenges surrounding achieving stereoinvertive SN2 and SN1 reactions at tertiary carbon centers. This is followed by discussions on stereoconvergent substitutions at tertiary carbon centers using strategies such as chiral-catalyst-directed SN1, radical-based nucleophilic substitution, and halogen-bonding-assisted SN2X reactions. Mechanistic discussions provide insights on how these reactions can be differentiated.