作者:Zhi-Shi Ye、Mu-Wang Chen、Qing-An Chen、Lei Shi、Ying Duan、Yong-Gui Zhou
DOI:10.1002/anie.201205187
日期:2012.10.1
Highly efficient iridium‐catalyzed asymmetric hydrogenations of simple 2‐substituted pyridinium salts gives the chiral 2‐substituted piperidines with up to 93 % ee (see picture; cod=1,5‐cyclooctadiene; synphos=(5,6),(5′,6′)‐bis(ethylenedioxy)‐2,2′‐bis(diphenylphosphino)‐1,1′‐biphenyl). The key feature of this strategy is the activation of simple pyridines as the pyridinium salts, thus eliminating substrate
简单的2-取代的吡啶鎓盐的高效铱催化不对称氢化反应使手性2-取代的哌啶具有高达93% ee(参见图片; cod = 1,5-环辛二烯; synphos =(5,6),(5' ,6')-双(乙二氧基)-2,2'-双(二苯基膦基)-1,1'-联苯)。该策略的关键特征是将简单的吡啶活化为吡啶鎓盐,从而消除了底物抑制并增强了反应性。