The [5 + 2] cycloadditionreaction of 2-vinylaziridines with sulfonylisocyanates proceeded smoothly under mild conditions, and various cyclic ureas were isolated in high yields. The remarkable solvent effect on the reaction was observed, and the preferential formation of the seven-membered ring occurred when the reaction was carried out in CH2Cl2. The scope and limitation were studied, and the mechanism
Palladium-Catalyzed Dynamic Kinetic Asymmetric Transformations of Vinyl Aziridines with Nitrogen Heterocycles: Rapid Access to Biologically Active Pyrroles and Indoles
作者:Barry M. Trost、Maksim Osipov、Guangbin Dong
DOI:10.1021/ja1071509
日期:2010.11.10
heterocycles can serve as competent nucleophiles in the palladium-catalyzed dynamic kinetic asymmetric alkylation of vinyl aziridines. The resulting alkylated products were obtained with high regio-, chemo-, and enantioselectivity. Both substituted 1H-pyrroles and 1H-indoles were successfully employed to give exclusively the branched N-alkylated products. The synthetic utility of this process was demonstrated
我们报告说,氮杂环可以在钯催化的乙烯基氮丙啶动态动力学不对称烷基化中作为有能力的亲核试剂。得到的烷基化产物具有高区域选择性、化学选择性和对映选择性。取代的 1H-吡咯和 1H-吲哚都被成功地用于得到支化的 N-烷基化产物。通过将该方法应用于制备几种药物化学先导化合物和溴吡咯生物碱,包括 longamide B、longamide B 甲酯、hanishin、agesamides A 和 B 以及环碘酮,证明了该方法的合成效用。
Metal-free aza-Claisen type ring expansion of vinyl aziridines: an expeditious synthesis of seven membered N-heterocycles
作者:Deepak Singh、Hyun-Joon Ha
DOI:10.1039/c8ob03029d
日期:——
A metal-free approach for the synthesis of 7-membered aza-heterocycles has been developed by the intermolecular [5 + 2] cycloaddition of non-activated vinylaziridines and alkynes. This method has a broad substrate scope under mild reaction conditions to afford structurally diverse 7-membered N-heterocycles in high yield up to 92%.
A novel Pd-catalyzed asymmetric annulation between 5-bromopyrrole-2-carboxylate esters and vinyl aziridines has been developed to efficiently construct pyrrolopiperazinones, which can serve as key intermediates in the enantioselective syntheses of pyrrole alkaloid natural products. In this paper, the totalsynthesis of (-)-longamideB in five steps and the first total syntheses of agesamides A and