title: Selective Stille coupling reactions of 3-chloro-5-halo(pseudohalo)-4H-1,2,6-thiadiazin-4-ones.
abstract: A series of 3-chloro-5-halo(pseudohalo)-4H-1,2,6-thiadiazin-4-ones (halo/pseudohalo = Br, I, OTf) are prepared from 3,5-dichloro-4H-1,2,6-thiadiazin-4-one (3) in good yields. Of these the triflate reacts with tributyltin arenes (Stille couplings) chemoselectively to give only the  5-aryl-3-chloro-4H-1,2,6-thiadiazin-4-ones in high yields. This allowed the preparation of a series of unsymmetrical biaryl thiadiazines and ultimately a series of oligomers. Furthermore, treatment of 3-chloro-5-iodo-4H-1,2,6-thiadiazin-4-one (10) with Bu(3)SnH and Pd(OAc)(2) gave the bithiadiazinone which can also be further arylated via the Stille reaction to give bisthien-2-yl and bis(N-methylpyrrol-2-yl) analogs.
authors: Department of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus.
authors: Heraklidia A
authors: HA
authors: Ioannidou
authors: Christos
authors: C
authors: Kizas
authors: Panayiotis A
authors: PA
authors: Koutentis