Enhanced Reactivity Results in Reduced Catalytic Performance: Unexpected Ligand Reactivity of a Bis(<i>N</i>-2,6-diisopropylphenylperflourophenyl-amidate)titanium-bis(diethylamido) Hydroamination Precatalyst
作者:Jason A. Bexrud、Chunyu Li、Laurel L. Schafer
DOI:10.1021/om700653t
日期:2007.12.1
A bis(amidate)titanium-bis(amido) complex incorporating electron withdrawing pentafluorophenyl substituents has been prepared to enhance reactivity in this class of hydroamination precatalyst. This bis(N-2,6-diisopropylphenylperflourophenylamidate)titanium-bis(diethylamido) titanium complex has been fully characterized, including its X-ray crystal structure. As a precatalyst, the title compound proved
已经制备了结合有吸电子五氟苯基取代基的双(氨基酸酯)钛-双(酰胺基)配合物以增强在这类氢化胺化预催化剂中的反应性。此双(Ñ-2,6-二异丙基苯基全氟苯基氨基甲酸酯)钛-双(二乙基氨基)钛配合物已得到充分表征,包括其X射线晶体结构。作为前催化剂,该标题化合物被证明可有效地与伯胺进行内部和末端炔烃的分子间加氢胺化,收率高达97%,且中等分子内烯烃的加氢胺化作用。但是,这种配合物的高反应性也会导致某些末端炔烃的马尔可夫尼可夫/反马尔可夫尼可夫选择性降低。底物范围的限制表明,由于胺底物向酰胺化物配体的五氟苯基取代基进行亲核加成的直接结果,该配合物易于分解。