通过（-）-鹰爪豆碱介导的炔基氨基甲酸酯锂化反应合成对映体富集的丙二烯。
Synthesis of enantiomerically enriched allenes by (-)-sparteine-mediated lithiation of alkynyl carbamates.
作者信息
Schultz-Fademrecht C, Wibbeling B, Fröhlich R, Hoppe D
机构信息
Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany.
出版信息
Org Lett. 2001 Apr 19;3(8):1221-4. doi: 10.1021/ol0157104.
[reaction: see text]. The alpha-deprotonation of alkynyl carbamates 3 with the chiral base (-)-sparteine (4)/n-butyllithium, transmetalation with ClTi(O(i)()Pr)3, and subsequent substitution with an aldehyde results in the formation of enantioenriched 4-hydroxyallenyl carbamates 11. Stereoselection is determined by dynamic resolution of the lithium/(-)-sparteine complexes by selective crystallization.
[反应：见正文]。炔基氨基甲酸酯3与手性碱（-）-鹰爪豆碱（4）/正丁基锂进行α-去质子化反应，与三异丙氧基氯化钛进行转金属化反应，随后用醛进行取代反应，生成对映体富集的4-羟基亚丙二烯基氨基甲酸酯11。立体选择性由锂/（-）-鹰爪豆碱配合物通过选择性结晶的动态拆分来决定。
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