Department of Chemistry, Umeå University , 90187 Umeå, Sweden.
Centre for Analysis and Synthesis, Lund University , 22100 Lund, Sweden.
Org Lett. 2016 Dec 16;18(24):6228-6231. doi: 10.1021/acs.orglett.6b02667. Epub 2016 Nov 28.
Regio- and stereoselective addition of alkyl Grignard reagents to pyridine-N-oxides gave C2-alkylated N-hydroxy-1,2,5,6-tetrahydropyridines and trans-2,3-disubstituted N-hydroxy-1,2,5,6-tetrahydropyridines in good to excellent yields. These intermediates were aromatized or alternatively reduced in one-pot methodologies for efficient syntheses of alkylpyridines or piperidines, respectively. These reactions have a broad substrate scope and short reaction times.
区域和立体选择性地将烷基格氏试剂添加到吡啶-N-氧化物中,以高产率得到 C2-烷基化的 N-羟基-1,2,5,6-四氢吡啶和反式-2,3-二取代的 N-羟基-1,2,5,6-四氢吡啶。这些中间体可以通过一锅法进行芳构化或还原,分别高效合成烷基吡啶或哌啶。这些反应具有广泛的底物范围和较短的反应时间。