by Pd(II) complexes, such as bis-acetonitrile palladium(II) bromide, followed by cyclocarbonylation of the resulting adducts with Ni(CO)4 in CH3CN containing precise amounts of CH3OH and Et3N is a better procedure than the direct cyclocarbonylation of these substrates mediated by Ni(CO)4 for preparation of cyclopentenones, specially for monosubstituted acetylenes or weakly polarized disubstituted acetylenes
在Pd(II)配合物(如双
乙腈钯(II)
溴化物)催化的炔属衍
生物中添加烯丙基卤化物,然后在含精确量CH 3的CH 3 CN中用Ni(CO)4环化所得的加合物。OH和Et 3 N比由Ni(CO)4介导的这些底物进行直接环羰基化来制备
环戊烯,特别是对于单取代的
乙炔或弱极化的二取代的
乙炔而言,是一种更好的方法。