Kinetic resolution of 1-(benzofuran-2-yl)ethanols by lipase-catalyzed enantiomer selective reactions
摘要:
Kinetic resolution of racemic 1-(benzofuran-2-yl)ethanols rac-1a-d was performed by lipase-catalyzed enantiomer selective acylation (Emuch greater than100) yielding (1R)-1-acetoxy-1-(benzofuran-2-yl)ethanes (R)-2a-d and (1S)-1-(benzofuran-2-yl)ethanois (S)-1a-d in highly enantiopure form. The degree of enantiomer selectivity for enzymatic alcoholysis/hydrolysis processes starting from racemic 1-acetoxy-1-(benzofuran-2-yl)ethane rac-2 was also tested under various conditions including supercritical CO2 medium. Racemization-free lipase-catalyzed ethanolysis of the (1R)-1-acetoxy-1-(benzofuran-2-yl)ethanes (R)-2a-d yielded almost quantitatively the enantiopure (1R)-1-(benzofuran-2-yl)ethanols (R)-1a-d. (C) 2003 Elsevier Science Ltd. All rights reserved.
Optically active 1-(benzofuran-2-yl)ethanols and ethane-1,2-diols by enantiotopic selective bioreductions
摘要:
Enantiotopic selective reduction of 1-(benzofuran-2-yl)ethanones 1a-d, 1-(benzofuran-2-yl)-2-hydroxyethanones 4a-c and 2-acetoxy-1-(benzofuran-2-yl)ethanones 3a-c was performed by baker's yeast for preparation of optically active (benzofuran-2-yl)carbinols [(S)-5a-d, (S)-6a-c and (R)-6a-c, enantiomeric excess from 55 to 93% ee]. (C) 2003 Elsevier Science Ltd. All rights reserved.
ns in water has been accomplished via Pd/C catalyzed reaction of o-iodophenols with terminal alkynes in the presence of PPh3, CuI and prolinol. This method can tolerate a variety of functional groups present in the alkynes as well as base labile nitro group in the o-iodophenols. The protocol does not require the use of a phasetransfercatalyst or water-soluble phosphine ligands and is free from the
2-烷基/芳基取代的苯并[一种高效合成b ]呋喃/硝基苯并[ b / C]水呋喃已经经由钯而完成催化反应ö与PPH的存在末端炔烃-iodophenols 3,碘化亚铜和脯氨醇。该方法可以耐受炔烃中存在的各种官能团以及邻碘苯酚中的碱不稳定的硝基。该方案不需要使用相转移催化剂或水溶性膦配体,并且无需使用任何有机助溶剂。