Pyridonate-Supported Titanium(III). Benzylamine as an Easy-To-Use Reductant

The reaction of bis­(3-phenyl-2-pyridonate)­Ti­(NMe2)2 with excess benzylamine leads to an unexpected reduction of the metal center from Ti­(IV) to Ti­(III). The reduced titanium species was isolated and revealed as tris­(3-phenyl-2-pyridonate)­Ti­(NH2Bn)2. Ammonia and N-benzyl-1-phenylmethanimine are released as byproducts of the reaction, thereby confirming benzylamine as a mild reductant. This new pyridonate-supported titanium­(III) complex has been fully characterized, and experimental data and theoretical calculations confirm a d1 metal center with no ligand-based radical character. This Ti­(III) complex does not react with aminoalkenes, suggesting that radical species are not viable intermediates for the hydroaminoalkylation or hydroamination reaction.双(3-苯基-2-吡啶酮合)二(二甲氨基)钛(IV)与过量苄胺的反应，会引发金属中心从四价钛到三价钛的意外还原。所分离得到的还原态钛物种经表征确定为三(3-苯基-2-吡啶酮合)二(苄氨基)钛(III)。该反应的副产物为氨与N-苄基苯甲亚胺，由此证实苄胺是一种温和还原剂。这种以吡啶酮合配体支撑的新型三价钛配合物已得到全面表征，实验数据与理论计算均证实其金属中心为d¹构型，且不存在配体自由基特性。该三价钛配合物不与氨基烯烃发生反应，这表明自由基物种并非氢氨基烷基化反应或氢胺化反应的可行中间体。