Enantioselective Synthesis of (−)-CP-55940 via Ruthenium- Catalyzed Asymmetric Hydrogenation of Ketones
作者:Li-Jie Cheng、Jian-Hua Xie、Li-Xin Wang、Qi-Lin Zhou
DOI:10.1002/adsc.201100898
日期:2012.4.16
A new and efficient catalytic asymmetric synthesis of the potent cannabinoid receptor agonist (−)‐CP‐55940 has been developed by using ruthenium‐catalyzed asymmetric hydrogenation of racemic α‐aryl ketones via dynamic kinetic resolution (DKR) as a key step. With RuCl2‐SDPs/diamine [SDPs=7,7′‐bis(diarylphophino)‐1,1′‐spirobiindane] catalysts the asymmetric hydrogenation of racemic α‐arylcyclohexanones
强效的大麻素受体激动剂的新的和有效的催化不对称合成( - ) - CP-55940已经通过使用的钌催化不对称氢化开发外消旋α -芳基酮通过动态动力学拆分(DKR)作为关键步骤。用RuCl 2 -SDPs /二胺[SDPs = 7,7'-双(二芳基膦基)-1,1'-螺双茚满]催化剂,通过DKR进行外消旋α-芳基环己酮的不对称氢化,可以提供高收率的相应的顺式-β-芳基环己醇。ee高达99.3%,顺式选择性> 99:1 。在环己烷环上的乙烯缩酮基和邻位的底物6的苯环上的-甲氧基对氢化的选择性和反应性影响很小。基于这种高效的不对称酮氢化反应,从市售的3-甲氧基苯甲醛和1,4-环己烯二酮单乙缩醛开始,以13个步骤(最长的线性步骤)合成了(-)-CP-55940,总产率为14.6%。