Catalytic Asymmetric Reduction of a 3,4-Dihydroisoquinoline for the Large-Scale Production of Almorexant: Hydrogenation or Transfer Hydrogenation?
作者:Gerard K. M. Verzijl、André H. M. de Vries、Johannes G. de Vries、Peter Kapitan、Thomas Dax、Matthias Helms、Zarghun Nazir、Wolfgang Skranc、Christoph Imboden、Juergen Stichler、Richard A. Ward、Stefan Abele、Laurent Lefort
DOI:10.1021/op400268f
日期:2013.12.20
presented for the enantioselective synthesis of the tetrahydroisoquinoline core of almorexant (ACT-078573A), a dual orexin receptor antagonist. Initial clinical supplies were secured by the Noyori Ru-catalyzed asymmetric transfer hydrogenation (Ru-Noyori ATH) of the dihydroisoquinoline precursor. Both the yield and enantioselectivity eroded upon scale-up. A broad screening exercise identified TaniaPhos
提出了几种方法用于对映体选择性合成alorexant的四氢异喹啉核心(ACT-078573A),一种双orexin受体拮抗剂。最初的临床供应是通过Noyori Ru催化的二氢异喹啉前体的不对称转移氢化(Ru-Noyori ATH)获得的。规模扩大时,产率和对映选择性均受到侵蚀。广泛的筛选工作确定了TaniaPhos是通过专用的催化剂预处理方案进行铱催化的不对称氢化反应的配体,最终生产了超过6吨的四氢异喹啉乙酸盐。主要的成本贡献者是TaniaPhos。通过将Ru-Noyori ATH的二氢异喹啉底物转换为其甲磺酸盐,该ATH后来成功地还原为实际应用,输送数百公斤的四氢异喹啉,从而显着降低了催化剂成本贡献。比较了这两种方法的绿色和效率指标。