Microwave acceleration in DABAL-Me3-mediated amide formation

Facile direct coupling of esters and secondary amines to afford tertiary amides proceeds under microwave irradiation using the air-stable trimethylaluminium source DABAL-Me3 [(DABCO)(AlMe3)2]. Excellent yields (88–98%) are attained for cyclic secondary amines in reactions that are complete in 5–16 min. The process can be extended to the formation of Weinreb amides (upto 76% from commercial MeNHOMe·HCl) in a one-pot procedure using NaH to liberate the free methoxyamine.