Enantioselective Synthesis of 3,4-Disubstituted <i>cis</i>- and <i>trans</i>-1,2,5-Thiadiazolidine-1,1-dioxides as Precursors for Chiral 1,2-Diamines
Christian Schüttler
Zhen Li-Böhmer
Klaus Harms
Paultheo von Zezschwitz
10.1021/ol3034753.s002
https://acs.figshare.com/articles/journal_contribution/Enantioselective_Synthesis_of_3_4_Disubstituted_i_cis_i_and_i_trans_i_1_2_5_Thiadiazolidine_1_1_dioxides_as_Precursors_for_Chiral_1_2_Diamines/2442958
Both, <i>cis</i>- and <i>trans</i>-3,4-disubstituted thiadiazolidines <b>5</b> and <b>6</b> can enantioselectively be obtained from thiadiazoles <b>2</b> 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 <i>cis</i>-isomers <b>5</b> which, under acidic conditions, undergo a novel isomerization into the <i>trans</i>-isomers <b>6</b>. These cyclic sulfamides can be transformed into 1,2-diamines as well as 2,3-diamino acids.
2013-02-15 00:00:00
enantioselectively
diamino
thiadiazoles 2
6.
diastereoselective hydride addition
hydrogenation
transfer
acidic conditions
diketone
DiaminesBoth
Chiral
Precursor
diamine
Disubstituted
cyclic sulfamides
thiadiazolidine
tran
Enantioselective Synthesis
novel isomerization