Lafage Mathieu, Heuclin Hadrien, Le Goff Xavier-Frédéric, Saffon-Merceron Nathalie, Mézailles Nicolas
Laboratoire "Hétérochimie Fondamentale et Appliquée", Université Paul Sabatier, CNRS UMR 5069, 31062 Toulouse Cedex (France).
Chemistry. 2014 Dec 15;20(51):16995-7003. doi: 10.1002/chem.201403708. Epub 2014 Oct 22.
The synthesis of two novel titanium carbene complexes from the bis(thiophosphinoyl)methanediide geminal dianion 1 (SCS(2-) ) is described. Dianion 1 reacts cleanly with 0.5 equivalents of [TiCl4 (thf)2 ] to afford the bis-carbene complex [(SCS)2 Ti] (2) in 86 % yield. The mono-carbene complex [(SCS)TiCl2 (thf)] (3) can also be obtained by using an excess of [TiCl4 (thf)2 ]. The structures of 2 and 3 are confirmed by X-ray crystallography. A strong nucleophilic reactivity towards various electrophiles (ketones and aldehydes) is observed. The reaction of 3 with N,N'-dicyclohexylcarbodiimide (DCC) and phenyl isocyanate leads to the formation of two novel diphosphinoketenimines 8 a and 8 b. The bis-titanium guanidinate complex 9 is trapped as the by-product of the reaction with DCC. The X-ray crystal structures of 8 a and 9 are presented. The mechanism of the reaction between complex 3 and DCC is rationalized by DFT studies.
描述了由双（硫代膦酰基）亚甲基双负离子1（SCS(2-)）合成两种新型钛卡宾配合物的过程。双负离子1与0.5当量的[TiCl4(thf)2]发生干净的反应，以86%的产率得到双卡宾配合物[(SCS)2Ti]（2）。单卡宾配合物[(SCS)TiCl2(thf)]（3）也可以通过使用过量的[TiCl4(thf)2]获得。2和3的结构通过X射线晶体学得到证实。观察到其对各种亲电试剂（酮和醛）具有很强的亲核反应活性。3与N,N'-二环己基碳二亚胺（DCC）和苯基异氰酸酯的反应导致形成两种新型二膦基酮亚胺8a和8b。双钛胍基配合物9作为与DCC反应的副产物被捕获。给出了8a和9的X射线晶体结构。通过密度泛函理论（DFT）研究对配合物3与DCC之间的反应机理进行了合理化解释。
