Departamento de Química Inorgánica, Orgánica y Bioquímica, Universidad de Castilla-La Mancha, Instituto de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL), Facultad de Ciencias del Medio Ambiente, Avda. Carlos III, s/n, 45071 Toledo, Spain.
Chemistry. 2012 Feb 20;18(8):2319-26. doi: 10.1002/chem.201103026. Epub 2012 Jan 20.
Tantalum complexes [TaCpMe{κ(4)-C,N,O,O-(OCH(2))(OCHC(CH(2)NMe(2))=CH)py}] (4) and [TaCpMe{κ(4)-C,N,O,O-(OCH(2))(OCHC(CH(2)NH(2))=CH)py}] (5), which contain modified alkoxide pincer ligands, were synthesized from the reactions of [TaCpMe{κ(3)-N,O,O-(OCH(2))(OCH)py}] (Cp = η(5)-C(5)Me(5)) with HC≡CCH(2)NMe(2) and HC≡CCH(2)NH(2), respectively. The reactions of [TaCpMe{κ(4)-C,N,O,O-(OCH(2))(OCHC(Ph)=CH)py}] (2) and [TaCpMe{κ(4)-C,N,O,O-(OCH(2))(OCHC(SiMe(3))=CH)py}] (3) with triflic acid (1:2 molar ratio) rendered the corresponding bis-triflate derivatives [TaCp*(OTf)(2){κ(3)-N,O,O-(OCH(2))(OCHC(Ph)=CH(2))py}] (6) and [TaCp*(OTf)(2){κ(3)-N,O,O-(OCH(2))(OCHC(SiMe(3))=CH(2))py}] (7), respectively. Complex 4 reacted with triflic acid in a 1:2 molar ratio to selectively yield the water-soluble cationic complex [TaCp*(OTf){κ(4)-C,N,O,O-(OCH(2))(OCHC(CH(2)NHMe(2))=CH)py}]OTf (8). Compound 8 reacted with water to afford the hydrolyzed complex TaCp*(OH)(H(2)O){κ(3)-N,O,O-(OCH(2))(OCHC(CH(2)NHMe(2))=CH(2))py}(2) (9). Protonation of compound 8 with triflic acid gave the new tantalum compound TaCp*(OTf){κ(4)-C,N,O,O-(OCH(2))(HOCHC(CH(2)NHMe(2))=CH)py}(2) (10), which afforded the corresponding protonolysis derivative TaCp*(OTf)(2){κ(3)-N,O,O-(OCH(2))(HOCHC(CH(2)NHMe(2))=CH(2))py} (11) in solution. Complex 8 reacted with CNtBu and potassium 2-isocyanoacetate to give the corresponding iminoacyl derivatives 12 and 13, respectively. The molecular structures of complexes 5, 7, and 10 were established by single-crystal X-ray diffraction studies.
钽配合物 [TaCpMe{κ(4)-C,N,O,O-(OCH(2))(OCHC(CH(2)NMe(2))=CH)py}] (4) 和 [TaCpMe{κ(4)-C,N,O,O-(OCH(2))(OCHC(CH(2)NH(2))=CH)py}] (5)，它们含有经过修饰的烷氧基 pincer 配体，是通过 [TaCpMe{κ(3)-N,O,O-(OCH(2))(OCH)py}] (Cp = η(5)-C(5)Me(5)) 与 HC≡CCH(2)NMe(2) 和 HC≡CCH(2)NH(2) 分别反应得到的。[TaCpMe{κ(4)-C,N,O,O-(OCH(2))(OCHC(Ph)=CH)py}] (2) 和 [TaCpMe{κ(4)-C,N,O,O-(OCH(2))(OCHC(SiMe(3))=CH)py}] (3) 与三氟磺酸 (1:2 摩尔比) 反应，分别得到相应的双三氟甲磺酸酯衍生物 [TaCp*(OTf)(2){κ(3)-N,O,O-(OCH(2))(OCHC(Ph)=CH(2))py}] (6) 和 [TaCp*(OTf)(2){κ(3)-N,O,O-(OCH(2))(OCHC(SiMe(3))=CH(2))py}] (7)。配合物 4 与三氟磺酸以 1:2 的摩尔比反应，选择性地生成水溶性阳离子配合物 [TaCp*(OTf){κ(4)-C,N,O,O-(OCH(2))(OCHC(CH(2)NHMe(2))=CH)py}]OTf (8)。化合物 8 与水反应得到水解配合物 TaCp*(OH)(H(2)O){κ(3)-N,O,O-(OCH(2))(OCHC(CH(2)NHMe(2))=CH(2))py}(2) (9)。用三氟磺酸对化合物 8 进行质子化得到新的钽化合物 TaCp*(OTf){κ(4)-C,N,O,O-(OCH(2))(HOCHC(CH(2)NHMe(2))=CH)py}(2) (10)，它在溶液中提供了相应的质子解衍生物 TaCp*(OTf)(2){κ(3)-N,O,O-(OCH(2))(HOCHC(CH(2)NHMe(2))=CH(2))py} (11)。配合物 8 与 CNtBu 和钾 2-异氰酸酯反应，分别得到相应的亚氨基酰衍生物 12 和 13。通过单晶 X 射线衍射研究确定了配合物 5、7 和 10 的分子结构。
