Enantioselective Synthesis of Pyrrolidine-, Piperidine-, and Azepane-Type <i>N</i>-Heterocycles with α-Alkenyl Substitution: The CpRu-Catalyzed Dehydrative Intramolecular <i>N</i>-Allylation Approach
作者:Tomoaki Seki、Shinji Tanaka、Masato Kitamura
DOI:10.1021/ol203218d
日期:2012.1.20
acid derivatives [(R)- or (S)-Cl-Naph-PyCOOCH2CH═CH2] catalyzes asymmetric intramolecular dehydrative N-allylation of N-substituted ω-amino- and -aminocarbonyl allylic alcohols with a substrate/catalyst ratio of up to 2000 to give α-alkenyl pyrrolidine-, piperidine-, and azepane-type N-heterocycles with an enantiomer ratio of up to >99:1. The wide range of applicable N-substitutions, including Boc, Cbz
A Brønsted‐acid‐catalyzed intramolecular enantioselective SN2′ reaction was developed utilizing trichloroacetimidate as a leavinggroup. The findings indicated that dual activation of the substrates is operative. This metal‐free allylic alkylation allows highly enantioselective access to 2‐vinylpyrrolidines bearing various substituents.
利用三氯乙酰亚氨酸酯作为离去基团开发了布朗斯台德酸催化的分子内对映选择性S N 2'反应。该发现表明底物的双重激活是有效的。这种无金属的烯丙基烷基化作用使对带有各种取代基的2-乙烯基吡咯烷酮具有高度对映选择性。