Synthesis of All Possible Stereoisomers of α-Branched [2.2]Paracyclophanylalkylamines
作者:Dieter Enders、Stephan Noll、Gerhard Raabe、Jan Runsink
DOI:10.1055/s-2008-1042941
日期:2008.4
The synthesis of all four possible stereoisomers of enantiopure and diastereomerically pure or highly enriched α-branched [2.2]paracyclophanylalkylamines is described. Key step is the nucleophilic 1,2-addition of alkyllithium reagents to hydrazones of 4-formyl[2.2]paracyclophane derived from the chiral auxiliaries SAMP/RAMP and RAMBO/SAMBO via chromatographic epimer separation. Reductive N-N bond cleavage of the resulting hydrazines, followed by treatment with benzyloxycarbonyl chloride afforded the N-Cbz-protected diastereo- and enantiopure (de, ee ÷ 99%) or diastereomerically enriched (de = 89-96%) title amines.
本研究描述了对映体和非对映体纯的或高度富集的δ-支链[2.2]对二环烷基胺的所有四种可能的立体异构体的合成。关键步骤是将烷基锂试剂通过亲核 1,2-加成法加到从手性助剂 SAMP/RAMP 和 RAMBO/SAMBO 衍生的 4-甲酰基[2.2]对二环烷的肼中,并通过色谱法分离出外嵌体。对得到的肼进行还原性 N-N 键裂解,然后用苄氧羰酰氯处理,得到 N-Cbz 保护的非对映和对映纯(de,ee ÷ 99%)或非对映富集(de = 89-96%)的标题胺。