Microwave-assisted synthesis of ortho-substituted diaryl N-(tert-butylsulfinyl)ketimines†
Abstract
A simple and efficient procedure for the synthesis of ortho-substituted diarylketimines has been developed under microwave irradiation, employing the corresponding diarylketones and (R)-(+)-tert-butylsulfinamide in the presence of Ti(OiPr)4. This approach allows the preparation of most final ketimines (3a–g) containing electron-donating groups in good yields in 1 h. For starting materials with strong electron-withdrawing groups, the desired (3h–m) products could also be prepared by increasing microwave energy and extension of the reaction time to 2.5 h.