Ziółkowska Aleksandra, Szynkiewicz Natalia, Pikies Jerzy, Ponikiewski Łukasz
Gdansk University of Technology, Faculty of Chemistry, Department of Inorganic Chemistry, Gabriela Narutowicza Str. 11/12, 80-233 Gdansk, Poland.
Dalton Trans. 2020 Oct 21;49(39):13635-13646. doi: 10.1039/d0dt02728f. Epub 2020 Sep 25.
A reactivity study of a β-diketiminate titanium(iii) phosphanylphosphido complex [NacNacTi(Cl){η-P(SiMe)-PtBu}] (1) towards ketones such as benzophenone, 9-fluorenone, acetophenone, cyclopentanone, cyclohexanone and cycloheptanone is reported. The reactions of 1 with aromatic ketones (without α-protons) directly lead to the Ti(iii) complex [NacNacTi(μ-Cl)(OSiMe)] (5) and Ti(iv) complexes with the pinacol condensation product [NacNacTi(OSiMe)(η-pinacolate)] (3), and phosphanylphosphaalkenes PhC[double bond, length as m-dash]P-PtBu (2) and (fluorenyl)C[double bond, length as m-dash]P-PtBu (6), respectively. The reaction with acetophenone leads to the titanium(iii) complex with the aldol condensation product as ligand [NacNacTi(Cl){OC{Me(Ph)}CH(C[double bond, length as m-dash]O)Ph}] (8) and in parallel to phosphanylphosphaalkene (Ph)MeC[double bond, length as m-dash]P-PtBu (9) and 5. The reactions of 1 with cyclic ketones (cyclopentanone and cyclohexanone) lead to Ti(iii) complexes [{(ArN[double bond, length as m-dash]C(Me)CHC(Me)[double bond, length as m-dash]NAr)((CH)CO)}Ti(Cl){PtBu-P(SiMe)((CH)CO)}] (10) and [{(ArN[double bond, length as m-dash]C(Me)CHC(Me)[double bond, length as m-dash]NAr)((CH)CO)}Ti(Cl){PtBu-P(SiMe)((CH)CO)}] (11), which are formed via the successive insertion of two molecules of ketone to one molecule of 1. The stability investigation of complexes 10 and 11 in a polar solvent (THF) revealed that under these conditions, the complexes decompose, resulting in titanium(iii) complexes with aldol condensation products and the expected phosphanylphosphaalkenes (CH)C[double bond, length as m-dash]P-PtBu (10a) and (CH)C[double bond, length as m-dash]P-PtBu (11a). In the reaction of 1 with cycloheptanone, only the Ti(iii) complex with the aldol condensation product [NacNacTi(Cl){OC(CH)}CH(C[double bond, length as m-dash]O)(CH)] (12) was isolated. The structures 3, 5, 8, 10, 11, 11b and 12 were characterized by X-ray spectroscopy, while all the phosphanylphosphaalkenes were characterized by NMR spectroscopy.
报道了一种β-二酮亚胺钛(III)膦基磷化物配合物[NacNacTi(Cl){η-P(SiMe)-PtBu}] (1)与二苯甲酮、9-芴酮、苯乙酮、环戊酮、环己酮和环庚酮等酮类的反应活性研究。1与芳香酮（无α-质子）的反应直接生成Ti(III)配合物[NacNacTi(μ-Cl)(OSiMe)] (5)和与频哪醇缩合产物的Ti(IV)配合物[NacNacTi(OSiMe)(η-频哪醇盐)] (3)，以及膦基磷烯PhC═P-PtBu (2)和(芴基)C═P-PtBu (6)。与苯乙酮的反应生成以羟醛缩合产物为配体的钛(III)配合物[NacNacTi(Cl){OC{Me(Ph)}CH(C═O)Ph}] (8)，同时生成膦基磷烯(Ph)MeC═P-PtBu (9)和5。1与环酮（环戊酮和环己酮）的反应生成Ti(III)配合物[{(ArN═C(Me)CHC(Me)═NAr)((CH)CO)}Ti(Cl){PtBu-P(SiMe)((CH)CO)}] (10)和[{(ArN═C(Me)CHC(Me)═NAr)((CH)CO)}Ti(Cl){PtBu-P(SiMe)((CH)CO)}] (11)，它们是通过两分子酮连续插入一分子1中形成的。对配合物10和11在极性溶剂（四氢呋喃）中的稳定性研究表明，在这些条件下，配合物分解，生成带有羟醛缩合产物的钛(III)配合物和预期的膦基磷烯(CH)C═P-PtBu (10a)和(CH)C═P-PtBu (11a)。在1与环庚酮的反应中，仅分离出了带有羟醛缩合产物的Ti(III)配合物[NacNacTi(Cl){OC(CH)}CH(C═O)(CH)] (12)。通过X射线光谱对结构3、5、8、10、11、11b和12进行了表征，而所有膦基磷烯则通过核磁共振光谱进行了表征。
