An Efficient Synthesis of 2- and 2,6-Substituted Piperidines Using Pd<sup>II</sup>-Catalyzed 1,3-Chirality Transfer Reaction
作者:Sudhir M. Hande、Nobuyuki Kawai、Jun’ichi Uenishi
DOI:10.1021/jo801926g
日期:2009.1.2
An efficient and general method for 2- and 2,6-substituted piperidine syntheses using PdII-catalyzed 1,3-chirality transfer reaction has been developed. The various N-protected ζ-amino allylic alcohols cyclize in the presence of PdCl2(CH3CN)2 to give substituted piperidines with high stereoselectivities. The syntheses of (S)-(+)- and (R)-(−)-coniine were achieved in 3 steps from the optically pure
已经开发出一种有效且通用的方法,该方法使用Pd II催化的1,3-手性转移反应合成2-和2,6-取代的哌啶。在PdCl 2(CH 3 CN)2的存在下,各种N-保护的ζ-氨基烯丙基醇环化,得到具有高立体选择性的取代哌啶。的合成(小号) - (+) -和(- [R )- ( - ) -毒芹碱是在3个步骤从光学纯烯丙基醇(实现小号) - 14C和(- [R - )14C分别。尽管在CH 2 Cl中反应速度明显加快如图2所示,THF给出最高的立体选择性。发现PdCl 2(CH 3 CN)2是该转化的最佳催化剂。提出了一种可行的反应途径,该反应途径包括形成由手性仲烯丙基醇引导的Pdπ-复合物,然后进行顺氮杂叠醛化,然后进行顺式消除PdCl(OH)。