Chiral Ion-Pair Organocatalyst-Promoted Efficient Enantio-selective Reduction of α-Hydroxy Ketones
作者:Yiliang Zhang、Li He、Lei Shi
DOI:10.1002/adsc.201800053
日期:2018.5.16
The enantioselective reduction of α‐hydroxy ketones with catecholborane has been developed employing 5 mol% of an 1,1′‐bi‐2‐naphthol (BINOL)‐derived ion‐pair organocatalyst. This methodology provides a straightforwardaccess to the corresponding aromatic 1,2‐diols in high yields (up to 90%) with excellent enantioselectivities (up to 97%). Furthermore, the α‐amino ketones also could be reduced with
of alkyl aryl ketones to Oxone®/trifluoroacetic anhydride in the presence of a catalytic amount of iodobenzene affords a-hydroxyalkyl aryl ketones in good yield. This method provides an effective and economical entry for the installation of α-hydroxy moieties into ketones and should find wide application in the construction of the α-hydroxy ketone subunit in natural product synthesis.
[EN] FLAVONOID COMPOUNDS AS THERAPEUTIC ANTIOXIDANTS<br/>[FR] COMPOSES FLAVONOIDES EN TANT QU'ANTIOXYDANTS THERAPEUTIQUES
申请人:ROWETT RES INST
公开号:WO2004007475A1
公开(公告)日:2004-01-22
Novel flavonoid compounds having anti-oxidant activity are described. Formula (1). The compounds have been shown to exhibit anti-oxidative properties in biological systems and their utility in a sunscreen or skincare composition or to treat conditions involving oxidative damage, especially curative or prophylactic treatment of Alzheimer's disease or ischaemia-reperfusion and injury, is described.
A Unified Approach for Divergent Synthesis of Heterocycles
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TMSOTf‐Catalyzed Formal [3+2] Cycloaddition of Electron‐Rich Alkynes
作者:Ping Chen、Wei Cao、Xiangqian Li、Dayong Shi
DOI:10.1002/adsc.202100769
日期:2021.10.19
construction of polysubstituted five-membered heterocycles via TMSOTf-catalyzed formal [3+2] cycloaddition of electron-rich alkynes, which features free from any metal, atom economy and water as the main by-product. Furthermore, alkenyl ether adduct has been verified as the key intermediate. Notably, by utilizing this approach, we can synthesize a broad range of polysubstituted furans, thiophenes and pyrroles