Enantioselective deprotometalation of alkyl ferrocenecarboxylates using bimetallic bases
作者:Gandrath Dayaker、William Erb、Madani Hedidi、Floris Chevallier、Marielle Blot、Philippe C. Gros、Göran Hilmersson、Thierry Roisnel、Vincent Dorcet、Ghenia Bentabed-Ababsa、Florence Mongin
DOI:10.1039/d1nj04526a
日期:——
alkyl-containing lithium zincates, 1 : 1 mixtures of lithium and zinc amides were tested. Chiral (H-exo-born-R or H-endo-born-S) or/and achiral (lithium 2,2,6,6-tetramethylpiperidide or lithium diisopropylamide) secondary amines gave good results, the best (81% yield and 44% ee in favor of the RP enantiomer) being obtained by using (endo-born-S)3ZnLi in THF at room temperature. Among other secondary amines also
描述了使用混合锂-锌或锂-镉碱对二茂铁羧酸烷基酯 (FcCO 2 R) 进行对映选择性去金属化。以FcCO 2 Me为底物,由外-(α R )-或内-(α S ) -N- (α-苯乙基)冰片胺( H-外-本-R或H- )制备手性烷基氨基锌酸锂内生-S ) 进行了测试;最好的结果(27%产率和62%ee的赞成的[R P对映体)通过使用卜得到2(内切-born-S ) ZnLi 在四氢呋喃 (THF) 中在 -30 °C 下碘分解。由于 FcCO 2 Me 与含烷基的锌酸锂的相容性低,因此测试了氨基化锂和氨基化锌的 1:1 混合物。手性(H- exo- born- R或H- endo- born- S)或/和非手性(2,2,6,6-四甲基哌啶锂或二异丙基氨基锂)仲胺得到了很好的结果,最好的(81%的产率和44% ee 有利于R P对映异构体)是通过在室温下在 THF 中使用(内生S)3 ZnLi