作者:Dieter Enders、Stefan Wallert
DOI:10.1055/s-2002-19766
日期:——
The Lewis acid catalyzed asymmetric synthesis of β-amino-cyclohexyl sulfonates via aza-Michael addition is reported. As key step the addition of (S)-1-amino-2-methoxymethyl-pyrrolidine (SAMP) or (R,R,R)-2-amino-3-methoxymethyl-2-azabicyclo[3.3.0]-octane (RAMBO) to alkenyl-cyclohexyl sulfonates is applied, to give β-hydrazino sulfonates in moderate to good yields and diastereomeric excesses (yield = 41-85%, de = 55-90%). The epimers are separated by preparative HPLC, followed by reductive N-N bond cleavage with BH3·THF and protection of the resulting amines with CbzCl to afford N Cbz-protected-β-amino-cyclohexyl sulfonates in moderate to good yields (38-68%, 2 steps) and enantiomeric excesses (ee) of ≥96%.
报告了在路易斯酸催化下,通过偶氮迈克尔加成法不对称合成δ-氨基环己基磺酸盐的过程。作为关键步骤,将(S)-1-氨基-2-甲氧基甲基吡咯烷(SAMP)或(R,R,R)-2-氨基-3-甲氧基甲基-2-氮杂双环[3.3.0]辛烷(RAMBO)加成到烯基-环己基磺酸盐中,得到δ-肼基磺酸盐,收率中等至良好,非对映过量(收率=41-85%,脱率=55-90%)。用制备型高效液相色谱法分离表聚物,然后用 BH3-THF 还原 N-N 键裂解,并用 CbzCl 保护得到的胺,得到 N Cbz 保护的δ-²-氨基环己基磺酸盐,收率中等至良好(38-68%,2 个步骤),对映体过量率(ee)≥96%。