[RuCl2(畏6-p-cymene)(P*)] and [RuCl2(魏-P*-畏6-arene)] Complexes Containing P-Stereogenic Phosphines. Activity in Transfer Hydrogenation and Inte

详细信息    查看全文

• 作者：Rosario Aznar ; Arnald Grabulosa ; Alberto Mannu ; Guillermo Muller ; Daniel Sainz ; Virtudes Moreno ; Merc猫 Font-Bardia ; Teresa Calvet ; Julia Lorenzo
• 刊名：Organometallics
• 出版年：2013
• 出版时间：April 22, 2013
• 年：2013
• 卷：32
• 期：8
• 页码：2344-2362
• 全文大小：723K
• 年卷期：v.32,no.8(April 22, 2013)
• ISSN：1520-6041

文摘

The preparation of a series of half-sandwich ruthenium complexes, [RuCl₂(畏⁶-p-cymene)(P*)] (P* = S-PMeRR鈥? and [RuCl₂(魏-P*-畏⁶-arene)], containing P-stereogenic phosphines is reported. The borane-protected P-stereogenic phosphines have been obtained by addition of the (H₃B)PMe₂R (R = t-Bu (1), Cy (2), Fc (3))/sec-BuLi/(鈭?-sparteine adduct to benzyl halides, carbonyl functions, and epoxides with yields between 40 and 90% and ee values in the 70鈥?9% range. Those containing an aryl secondary function have been used in the preparation of [RuCl₂(畏⁶-p-cymene)(P*)] complexes. Borane deprotection has been performed using HBF₄, except for (H₃B)PRMe(CH₂SiMe₂Ph) phosphines, where DABCO was used to avoid partial cleavage of the CH₂鈥揝i bond. In the case of (H₃B)P(t-Bu)Me(CH₂C(OH)Ph₂) (1l) the dehydrated phosphine was obtained. The tethered complexes were obtained by p-cymene substitution in chlorobenzene at 120 掳C, except for ferrocenyl-containing complexes, which decomposed upon heating. The presence of substituents in the aryl arm of some of the phosphines introduces new chiral elements in the tethered [RuCl₂(魏-P*-畏⁶-arene)] compounds. Full characterization of all compounds both in solution and in the solid state has been carried out. Crystal structure determinations of four phosphine鈥揵orane molecules confirm the S configuration at the phosphorus atom (1a,e,l and 2d). Moreover, the crystal structure of one p-cymene complex (5i) and four tethered complexes reveal the strain of the compounds with two atoms in the tether (7c,g,l and 8i). Tethering has a marked effect on the catalytic performance transfer hydrogenation of acetophenone and on the nature of hydridic species originating during the activation period. The chiral induction attains 58% ee with complexes with the bulkiest substituents in the pendant arm of the phosphine. Three of the prepared complexes can interact with DNA and present a reasonable cytotoxicity toward cancer cells. Intercalation of the free aromatic pendant arm of the phosphines seems to be fundamental for such interactions.