Evaluating<i>cis</i>-2,6-Dimethylpiperidide (<i>cis</i>-DMP) as a Base Component in Lithium-Mediated Zincation Chemistry
作者:David R. Armstrong、Jennifer A. Garden、Alan R. Kennedy、Sarah M. Leenhouts、Robert E. Mulvey、Philip O'Keefe、Charles T. O'Hara、Alan Steven
DOI:10.1002/chem.201301180
日期:2013.9.27
amide component in the lithium amide, Et2Zn and TMEDA system. Under certain conditions, the cis‐DMP base system was found to give improved results in comparison to HMDS and diisopropylamide (DA), and comparable results to a TMP system. Two novel complexes isolated from reactions of the di‐tert‐butylzincate and crystallographically characterised, namely the pre‐metallation complex [(iPr)2N(Ph)CO}LiZn(cis‐DMP)tBu2]
金属化化学的最新进展集中在混合金属(通常被食用)组合物中的庞大的仲酰胺 2,2,6,6-四甲基哌啶 (TMP)。然而,前体胺 TMP(H) 相当昂贵,因此更便宜的替代品将受到欢迎。因此,本研究旨在开发更便宜的非 TMP 基混合金属碱,并且由于选择顺式‐2,6-二甲基哌啶 ( cis ‐ DMP) 作为替代酰胺,开发顺式DMP 锌酸盐化学而受到的关注较少。与其富含甲基的对应物 TMP 相比。一种新的二乙基锌酸锂,[(TMEDA)LiZn( cis -DMP)Et 2 ] (TMEDA= N , N , N' ,N'-四甲基乙二胺)是通过 Li( cis- DMP)、Et 2 Zn 和 TMEDA的共络合合成的,并通过 NMR(包括 DOSY)光谱和 X 射线晶体学表征,显示出双核接触离子对排列。通过使用N , N-二异丙基苯甲酰胺作为测试芳香族底物,[(TMEDA)LiZn( cis- DMP)Et