16α-Azolyl-pregnenolone derivatives were prepared via 2-butyl-1,1,3,3-tetramethylguanidine (nBu-TMG) catalysed aza-Michael addition of 16-dehydropregnenolone (16-DHP) carried out in [bmim][BF4]. The application of the guanidine base and the imidazolium ionic liquid made it...