A Twist on Facial Selectivity of Hydride Reductions of Cyclic Ketones: Twist-Boat Conformers in Cyclohexanone, Piperidone, and Tropinone Reactions
作者:Sharon R. Neufeldt、Gonzalo Jiménez-Osés、Daniel L. Comins、K. N. Houk
DOI:10.1021/jo5022635
日期:2014.12.5
The role of twist-boat conformers of cyclohexanones in hydride reductions was explored. The hydride reductions of a cis-2,6-disubstituted N-acylpiperidone, an N-acyltropinone, and tert-butylcyclohexanone by lithium aluminum hydride and by a bulky borohydride reagent were investigated computationally and compared to experiment. Our results indicate that in certain cases, factors such as substrate conformation
探索了环己酮扭船构象在氢化物还原中的作用。通过计算研究了氢化铝锂和大体积硼氢化物试剂对顺式 2,6-二取代的N-酰基哌啶酮、 N-酰基托品酮和叔丁基环己酮的氢化物还原反应,并与实验进行了比较。我们的结果表明,在某些情况下,底物构象、亲核体体积和远程空间特征等因素可能会以一般 Felkin-Anh 模型难以预测的方式影响立体选择性。特别是,我们计算出扭船构象与使用小氢化物试剂(LiAlH 4 )但不使用大体积氢化物的顺式2,6-二取代N-酰基哌啶酮的氢化物还原的反应性和面选择性相关(三异丙基硼氢化锂)。