Tf 2 O-Promoted Regioselective Heteronucleophilic Ring-Opening Approaches of Tetrahydrofuran.

The ring-opening functionalization strategy in tetrahydrofuran (THF) represents an ideal approach to access different valuable structures. Herein, we report different operationally simple, efficient, unique, and practical regioselective heteronucleophilic ring-opening strategies for the THF system. Tf 2 O, which is a strong electrophilic activator, was found to generate a THF triflate intermediate that triggers the nucleophilicity of nitriles (Nu 1 ) and led to regioselective ring opening in the presence of different nucleophiles (Nu 2 ). Furthermore, the synthesis of different heteronucleophilic ring-opening dimerization products was attributed to the nucleophilicity of Nu 2 . We also demonstrated that use of borane-tetrahydrofuran (BTHF) can achieve challenging hydride addition in a similar manner.