126241-北京大学—中级有机化学-第三讲Reduction - Qilong - Shen - 图文

Reduction授课者：沈其龙办公室：新大楼819电话： 54925197E-mail: shenql@sioc.ac.cn上海有机化学研究所2011年秋R1OR2R1OR2HNuR1OHR2HR1OHR2NuHHHBAluminum Hydride Reducing Agents

Borohydride Reducing Agents

Li-selectride

? Need alcohol activation (EtOH)

NaBH4 less reactive than LiBH4, ? NaBH4/CeCl3 for enolizable carbonyl? NaBH4/CoCl2 for nitrile reduction? stable in aqueous solution even at pH > 3

NaCNBH3 less reactive than NaBH4

? LiBH Li-Selectride: bulky

4 can be in non protic solvents. Et2O>THF?? LiBHEt? REDAL-H: NaAlH3 (Super Hydride): stronger than LiAlH(OCH4? DIBAL-H: very selective. From ester to aldehyde

22OMe)2: non-polar solFor Example…