Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA.
Bioorg Med Chem Lett. 2011 May 1;21(9):2706-10. doi: 10.1016/j.bmcl.2010.11.121. Epub 2010 Dec 4.
The scope of enantioselective allylations employing Nakamura's allylzinc-bisoxazoline reagent was examined by performing allylations of a selection of readily available ketones. Low-to-moderate ee's were observed, and a computational study was conducted to rationalize the results. Examination of transition structures of previously performed allylations that proceeded with high ee revealed the importance of both local and global control elements in these successful reactions. The ability of density functional theory methods to estimate the enantioselectivity of these asymmetric ketone allylations was established. All allylations that were studied computationally exhibited low (<5 kcal/mol) activation barriers, a result that is consistent with the highly reactive nature of Nakamura's reagent.
采用 Nakamura 的烯丙基锌-双恶唑啉试剂的对映选择性烯丙基化的范围通过对一系列易得的酮进行烯丙基化来检查。观察到低至中等的 ee 值，并进行了计算研究以合理化结果。对具有高 ee 值的先前进行的烯丙基化的过渡态的检查揭示了局部和全局控制因素在这些成功反应中的重要性。密度泛函理论方法估计这些不对称酮烯丙基化的对映选择性的能力得到了确立。所有进行了计算研究的烯丙基化都表现出低（<5 kcal/mol）的活化能垒，这一结果与 Nakamura 试剂的高反应性一致。
