Asymmetric synthesis of homoproline derivatives via Rh(I)-catalyzed hydrogenation using chiral bisphosphines as ligands
摘要:
It has been demonstrated for the first time that Rh(I)-catalyzed asymmetric hydrogenation of cyclic beta-enamino acid derivatives I using chiral bisphosphines could be a highly efficient synthetic method for optically active homoproline derivatives. The enantioselectivity and conversion yield were largely dependent upon the chiral ligand. Using the Me-BDPMI forming a seven-membered metal chelate, the N-acetylated beta-enamino acid methyl ester la was hydrogenated to give optically active homoproline derivative 2a with 100% conversion and 96% ee. (C) 2004 Elsevier Ltd. All rights reserved.
Cyclic p-amino acids, homoproline, homopipecolic acid and 3-carboxy-methylmorpholine were obtained in high enantiomeric excesses by transition metal-catalyzed asymmetrichydrogenation of cyclic β-acylamino-alkenoates. These compounds were synthesized by a thio-Wittig reaction on N-protected thiolactames.
通过过渡金属催化的环状β-酰基氨基-烯酸酯的不对称氢化,以高对映体过量获得环状p-氨基酸、高脯氨酸、高哌啶酸和3-羧基-甲基吗啉。这些化合物是通过在 N 保护的硫代内酰胺上的硫代-维蒂希反应合成的。
Brunerie, Pascal; Celerier, Jean-Pierre; Petit, Huguette, Journal of Heterocyclic Chemistry, 1986, vol. 23, p. 1183 - 1188