Enantioselective synthesis of 3,4-disubstituted cis- and trans-1,2,5-thiadiazolidine-1,1-dioxides as precursors for chiral 1,2-diamines.
Both, cis- and trans-3,4-disubstituted thiadiazolidines 5 and 6 can enantioselectively be obtained from thiadiazoles 2 which, in turn, are efficiently prepared from the respective 1,2-diketone by an improved protocol. An asymmetric ruthenium-catalyzed transfer hydrogenation followed by a diastereoselective hydride addition furnishes exclusively the cis-isomers 5 which, under acidic conditions, undergo a novel isomerization into the trans-isomers 6. These cyclic sulfamides can be transformed into 1,2-diamines as well as 2,3-diamino acids.
Fachbereich Chemie, Philipps-Universität Marburg, 35032 Marburg, Germany.
Christian
C
Schüttler
Zhen
Z
Li-Böhmer
Klaus
K
Harms
Paultheo
P
von Zezschwitz
D002384:Catalysis; D003959:Diamines / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure; D012428:Ruthenium / Q000737:chemistry; D013237:Stereoisomerism; D013449:Sulfonamides / Q000737:chemistry*; D013830:Thiadiazoles / Q000138:chemical synthesis* / Q000737:chemistry
D003959:Diamines; D007659:Ketones; D013449:Sulfonamides; D013830:Thiadiazoles; D012428:Ruthenium