Synthesis of Diastereomeric Bis(oxazoline) Ligands Derived from (S,S)-1,1'-Bis(4-isopropyloxazolin-2-yl)ferrocene
Synthesis of Diastereomeric Bis(oxazoline) Ligands Derived from (S,S)-1,1'-Bis(4-isopropyloxazolin-2-yl)ferrocene
复制标题
(S,S)-1,1-双(4-异丙基恶唑啉-2-基)二茂铁衍生的非对映体双(恶唑啉)配体的合成
作者：
Richards C
以（S，S）-1，1 ′-双（4-异丙基恶唑啉-2-基）二茂铁为起始原料，通过选择性锂化反应和三甲基氯硅烷的加成反应，合成了所有可能的2-三甲基硅烷基和2，2 ′-二（三甲基硅烷基）取代的非对映异构体。在非对映选择性引入两个氘阻断基团并利用高kH/kD值进行锂化后，获得了（S，S，Rp，Rp）-非对映异构体，该方法也应用于相关的2，2 ′-二（二苯基甲醇）双恶唑啉配体的合成。
Starting from (S,S)-1,1′-bis(4-isopropyloxazolin-2-yl)ferrocene, all possible 2-trimethylsilyl- and 2,2′-di(trimethylsilyl)-substituted diastereoisomers, potential bisoxazoline ligands for use in asymmetric catalysis, were synthesised by selective lithiation followed by addition of trimethylsilyl chloride. Access to the (S,S,Rp,Rp)-diastereoisomer was achieved following diastereoselective introduction of two deuterium-blocking groups and utilisation of the highkH/kDvalue for lithiation, methodology that was also applied to the synthesis of a related 2,2′-di(diphenylmethanol)bisoxazoline ligand.