primary amine catalyzed efficient and practical protocol for the large-scale synthesis of Wieland–Miescher and Hajos–Parrishketones as well as their analogues. This article describes a simple chiral primary amine catalyzed efficient and practical protocol for the large-scale synthesis of Wieland–Miescher and Hajos–Parrishketones as well as their analogues.
A Highly Active Polymer-Supported Catalyst for Asymmetric Robinson Annulations in Continuous Flow
作者:Santiago Cañellas、Carles Ayats、Andrea H. Henseler、Miquel A. Pericàs
DOI:10.1021/acscatal.6b03286
日期:2017.2.3
preparation through Robinson annulation of enantiopure buildingblocks with both academic and industrial relevance, such as the Wieland–Miescher and Hajos–Parrish ketones, has suffered from important drawbacks, such as the need for high catalyst loading or extremely long reaction times. Here we report a heterogenized organocatalyst based on Luo’s diamine for fast and broad-scope enantioselective Robinson
efficient and practical protocol for the synthesis of both Wieland–Miescher ketone and Hajos–Parrishketone as well as their analogues. The reaction can be conducted in gram scale with 1% mol catalyst loading producing high enantioselectivity (up to 96% ee) and excellent yields (up to 98%). This procedure represents one of the most efficient methods for the synthesis of these versatile chiral building blocks
作者:Lisa M. Schneider、Volker M. Schmiedel、Tommaso Pecchioli、Dieter Lentz、Christian Merten、Mathias Christmann
DOI:10.1021/acs.orglett.7b00836
日期:2017.5.5
A modular synthesis of functionalized carbocyclic propellanes was developed. Formation of the first of two quaternary bridgehead centers has been achieved by desymmetrization of prostereogenic ketones by either Hajos–Parrish–Eder–Sauer–Wiechert-type processes or Werner’s catalytic asymmetric Wittig reaction. The obtained bicyclic enones were subjected to conjugate additions upon which the remaining