Esterification of carboxylic acids with alkyl halides can be efficiently catalyzed by tetrabutylammonium fluoride (TBAF) generated in situ from tetrabutylammonium hydrogensulfate (TBAHSO4) and KF·2H2O in THF. The general applicability and the characteristic feature of this approach has been amply demonstrated.
A metal‐free oxidative esterification or thio‐esterification of readily available substituted malononitrile and alcohol or thiol has been developed by simply mixing α‐substituted malononitrile and alcohol or thiol in the presence of base under a molecular oxygen atmosphere.