Cycloisomerisations in Pd-Catalysed Spiroannulations onto Chiral Pyrazine Derivatives
作者:Bjørg Møller、Kjell Undheim
DOI:10.1002/ejoc.200390038
日期:2003.1
in cyclisation reactions of dienes with the chiral auxiliary (2R)-2,5-dihydro-2-isopropyl-3,6-dimethoxypyrazine. Extensive NMR assignments are described and used in structure determinations. Isomer identification has been verified by a separate unequivocal synthesis. Nickel catalysis with MeMgBr was compatible with cross-coupling in the spiroannulated chiral auxiliary. (© Wiley-VCH Verlag GmbH & Co.
描述了一种用于 5-exo-trig-spiroannulations 的方法,该方法使用 Pd 配合物反式-双(μ-乙酰基)双 [o-(二-邻甲苯基膦酰基)苄基]二钯(II)作为催化剂在二烯与手性助剂 (2R)-2,5-二氢-2-异丙基-3,6-二甲氧基吡嗪。广泛的 NMR 分配被描述并用于结构测定。异构体鉴定已通过单独的明确合成验证。镍与 MeMgBr 的催化作用与螺环手性助剂中的交叉偶联相容。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)