Regioselective synthesis of optically active (pyrazolyl)pyridines with adjacent quaternary carbon stereocenter: chiral N,N-donating ligands
作者:Rafał Kowalczyk、Jacek Skarżewski
DOI:10.1016/j.tet.2004.10.092
日期:2005.1
Novel optically active 2-(pyrazol-1-yl)pyridines have been prepared using resolved the O-methyl ether of atrolactic acid as a source of the adjacent quaternary carbon stereocenter. Different regioisomers were formed selectively in the reaction of 2-hydrazinopyridines with the chiral 1,3-diketone and in the nucleophilic substitution of 2-chloropyridines with the potassium salt of the chiral pyrazole
新型光学活性的2-(吡唑-1-基)吡啶是通过使用拆分的邻苯二甲酸的O-甲基醚作为相邻的季碳立体中心的来源而制备的。在2-肼基吡啶与手性1,3-二酮的反应中以及在2-氯吡啶用手性吡唑的钾盐进行亲核取代中,选择性地形成了不同的区域异构体。第二种途径得到2-(吡唑-1-基)吡啶,其立体生成中心邻近吡唑环中的配位氮。此外,获得了基于2,6-双(吡唑基)吡啶和6,6'-双(吡唑基)-2,2'-联吡啶结构的新的C 2对称手性配体。