Enantioselective catalysis XVI: regio- and enantioselectivity in nickel-catalysed cross-coupling reactions of allylic substrates with Grignard reagents
Enantioselective catalysis XVI: regio- and enantioselectivity in nickel-catalysed cross-coupling reactions of allylic substrates with Grignard reagents
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DOI：
10.1016/s0020-1693(97)05770-8
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发表时间：
1998-03-03
影响因子：
2.8
通讯作者：
Nedden, HG
中科院分区：
文献类型：
--
作者：
Nagel, U;Nedden, HG
研究了由直链2-丁烯-1-基化合物和支链1-丁烯-3-基底物与苯基卤化镁的交叉偶联反应不对称合成3-苯基-1-丁烯。带有手性3，4-双（膦基）吡咯烷或3-（二苯基膦基）吡咯烷配体的镍和钯配合物已被用作催化剂。利用气液色谱对催化剂样品进行了定量分析和对映体组成的测定。区域选择性和对映选择性可以受到烯丙基底物中存在的离去基团的选择的影响，并且在单膦配体的情况下，还可以受到配体与镍的比例的选择的影响。研究了三种不同碱度和分子体积的3，4-双（膦基）吡咯烷配体中叔膦基对化学产率以及区域和对映选择性的影响。高的化学产率和光学产率（高达83.5%ee），可以专门获得与3，4-双（二苯基膦基）吡咯烷配体。这一结论与另一个产生3-苯基-1-丁烯（（1-苯基乙基）卤化镁和乙烯基卤化物作为起始化合物）的交叉偶联反应的结果相反。在该催化反应中，含3-（二苯基膦基）吡咯烷配体的镍配合物是最具对映选择性的催化剂。(C)1998年Elsevier Science S.A.
An investigation of the asymmetric synthesis of 3-phenyl-1-butene by the cross-coupling reaction of linear 2-butene-1-yl compounds and of branched 1-butene-3-yl substrates with phenylmagnesium halides is presented. Nickel and palladium complexes bearing chiral 3,4-bis(phosphanyl)pyrrolidine or 3-(diphenylphosphanyl)pyrrolidine ligands have been employed as catalysts. The quantitative analysis and the determination of enantiomeric composition of the catalytic samples were accomplished using enantioselective gas-liquid chromatography separations. Regio- and enantioselectivity can be influenced by the choice of the leaving group present in the allylic substrates and additionally by the choice of the ligand to nickel ratio in the case of monophosphane ligands. The influence of tertiary phosphanyl groups in three 3,4-bis(phosphanyl)pyrrolidine ligands, differing in basicity and molecular volume on chemical yield and on regio-and enantioselectivity is investigated. High chemical and optical yields (up to 83.5% ee) can be exclusively obtained with 3,4-bis(diphenylphosphanyl)pyrrolidine ligands. This conclusion contrasts with the results of another cross-coupling reaction yielding 3-phenyl-1-butene((1-phenylethyl)magnesium halides and vinyl halides as starting compounds). In this catalysis nickel complexes bearing 3-(diphenylphosphanyl)pyrrolidine ligands were the most enantioselective catalysts. (C) 1998 Elsevier Science S.A.