Bis(pyridyl)-silane and -methanol ligands IV. Catalytic application of nickel(II) complexes in the Kumada cross-coupling reaction
作者:Michael E. Wright、Myung-Jong Jin
DOI:10.1016/0022-328x(90)87185-g
日期:1990.5
reagents with chlorobenzene provided a dipolar aprotic solvent such as HMPA was employed. Optically pure ligands, 6-alkoxy-2-pyridyl}(Ar)CH(OMe) (5), were employed in the asymmetric cross-coupling reaction of (1-phenylethyl)magnesium chloride and bromoethene. Conversion of the Grignard reagent ranged from 73 to 88% with ∼50% chemical yields of 3-phenyl-1-butene with optical yields ranging from ∼0 to
双(2-吡啶基)硅烷配体MERSI的治疗(2-C 5 H ^ 4 N)2与(MeCN中)2 -NiBr 2,得到MERSI(2-C 5 H ^ 4 N)2 } NIBR 2(图3a,R = Me;3b,R = Ph)以优异的产率。后者的配合物为亮紫色结晶固体,在NMR光谱中具有顺磁性线展宽。尽管在溶液或固态下都无法检测到ESR信号。复杂3a被发现是格氏试剂与芳基卤化物和乙烯基卤化物交叉偶联的有效催化剂。如果使用偶极非质子传递溶剂(如HMPA),则催化系统还将烷基格氏试剂与氯苯偶合。光学纯的配体6-烷氧基-2-吡啶基}(Ar)CH(OMe)(5)用于(1-苯乙基)氯化镁与溴乙烯的不对称交叉偶联反应。格氏试剂的转化率为73%至88%,其中3-苯基-1-丁烯的化学收率为〜50%,光学收率为〜0%至11%。