Biomimetic type approach to the tricyclic core of xyloketals. Application to a short, stereocontrolled synthesis of alboatrin and first synthesis of xyloketal G
作者:Debayan Sarkar、Ramanathapuram V. Venkateswaran
DOI:10.1016/j.tet.2011.04.084
日期:2011.6
benzopyran ring system of xyloketals is described. An orthoester Claisen rearrangement of a chromenol and an intra-molecular cationic cyclization are the key steps in the synthesis. A short, stereocontrolled and high yield synthesis of the phytotoxic metabolite alboatrin was achieved employing this strategy. A unique case of Lewis acid catalyzed isomerization of epi-alboatrin to alboatrin was observed.
Iridium-Catalyzed Enantioselective Hydrogenation of Unsaturated Heterocyclic Acids
作者:Song Song、Shou-Fei Zhu、Liu-Yang Pu、Qi-Lin Zhou
DOI:10.1002/anie.201301341
日期:2013.6.3
binding: A highly enantioselectivehydrogenation of unsaturatedheterocyclicacids has been developed by using chiral iridium/spirophosphino oxazoline catalysts (see scheme; BArF−=tetrakis[3,5‐bis(trifluoromethyl)phenyl]borate, Boc=tert‐butoxycarbonyl). This reaction provided an efficient method for the preparation of optically active heterocyclicacids with excellent enantioselectivities.
螺旋结合:一种高度对映选择性的不饱和杂环羧酸的加氢已经通过使用手性铱/ spirophosphino恶唑啉催化剂开发(参见方案; BAR ˚F - =四[3,5-双(三氟甲基)苯基]硼酸盐,的Boc =叔丁氧羰基) 。该反应提供了制备具有优异对映选择性的旋光杂环酸的有效方法。