Organocatalytic Asymmetric Sulfa‐Michael Additions to α,β‐Unsaturated Sulfonates
作者:Dieter Enders、Krzysztof Hoffman
DOI:10.1002/ejoc.200801202
日期:2009.4
reactivity of α,β-unsaturated sulfonates and aromaticthiols in an organocatalyzed sulfa-Michael addition was explored. Bifunctional chiral thiourea catalysts were found to promote the reaction, and the corresponding Michael adducts were afforded in moderate to good yields (24–92 %) and with moderate levels of asymmetric induction (33–64 % ee). This study represents the first use of α,β-unsaturated
Asymmetric Synthesis of β-AminoCyclohexyl Sulfonates, β-Sultams and γ-Sultones
作者:Dieter Enders、Stefan Wallert、Jan Runsink
DOI:10.1055/s-2003-41029
日期:——
and protection of the resulting amines with CbzCl gave N-Cbz-protected β-aminocyclohexyl sulfonates 6a-k in moderate to good yields (38-68% over 2 steps) and high enantiomeric excesses (ee ≥ 96%). α-Alkylation of 6 with various electrophiles afforded α-alkyl-β-aminocyclohexyl sulphonates 10a-g in good to excellent yields (67-92%) and moderate to high diastereomeric excesses (de = 71-93%). After alkylation