Palladium-Catalyzed Enantioselective Allylic Substitution in the Presence of Monodentate Furanoside Phosphoramidites
作者:Maciej Majdecki、Janusz Jurczak、Tomasz Bauer
DOI:10.1002/cctc.201402933
日期:2015.3
D‐xylose and optically pure 1,1′‐bi‐2‐naphthol (BINOL), was used as ligands for the palladium‐catalyzed allylic alkylation and amination. The matched pair was formed from D‐xylose‐derivatives and (S)‐BINOL. The asymmetric induction depends strongly on the substituent at the C5 of the carbohydrate backbone; both bulky 5‐O‐pivaloyl and 5‐deoxy derivatives gave excellent results, whereas ligands with trityl
单齿呋喃糖苷亚磷酰胺库可轻松地由廉价的D-木糖和光学纯的1,1'-bi-2-萘酚(BINOL)合成,用作钯催化的烯丙基烷基化和胺化反应的配体。配对是由D-木糖衍生物和(S)-BINOL形成的。不对称诱导在很大程度上取决于碳水化合物主链C5处的取代基。庞大的5- O-新戊酰基和5-脱氧衍生物均具有出色的结果,而在C5位具有三苯甲基保护的配体则导致低ee与配置相反的值。用于添加的溶剂也非常重要,在乙醚中观察到最高的对映选择性。对于空间需求量高的烯丙基乙酸酯,烷基化和胺化反应均达到98-99%ee的最佳结果。