Regioselective and Stereoselective Copper(I)-Promoted Allylation and Conjugate Addition of <i>N</i>-Boc-2-lithiopyrrolidine and <i>N</i>-Boc-2-lithiopiperidine
作者:Iain Coldham、Daniele Leonori
DOI:10.1021/jo100415x
日期:2010.6.18
regioselectively (SN2 mechanism). Addition to an enone or α,β-unsaturated ester occurs by 1,4-addition. Asymmetric deprotonation of N-Boc-pyrrolidine or dynamic resolution in the presence of a chiral ligand of N-Boc-2-lithiopiperidine followed by the zinc/copper chemistry was successful and gave the allylated pyrrolidine and piperidine products with good enantioselectivity, although use of the copper iodide
铜盐已被筛选的转移金属化和电淬火ñ -叔丁氧羰基-2- lithiopyrrolidine(Ñ -Boc-2- lithiopyrrolidine)和Ñ -Boc-2- lithiopiperidine,通过去质子化而形成Ñ -Boc -吡咯烷和ñ - Boc-哌啶分别。然后,用氯化锌(溶解了氯化锂)进行重金属化,然后进行烯丙基化,生成区域异构体的混合物(S N 2和S N 2'产物),而用碘化铜·TMEDA进行重金属化,则区域选择性地进行烯丙基化(S N2机制)。通过1,4-加成发生烯键或α,β-不饱和酯的加成。N -Boc-吡咯烷的不对称去质子化或在N -Boc-2-lithiopiperidine的手性配体存在下的动态拆分以及随后的锌/铜化学反应是成功的,尽管使用了N -Boc-2-lithiopiperidine的手性配体,但烯丙基化的吡咯烷和哌啶产物具有良好的对映选择性碘化铜的化