Chelate-stabilized alkoxopalladium(II) complexes with chiral phosphine-substituted carbohydrate ligands
作者:Ji-Cheng Shi、Da-Xu Wu、Ting-Bin Weng、Mao-Chun Hong、Qiu-Tian Liu、Bei-Sheng Kang、Shi-Jie Lu、Han-Qing Wang
DOI:10.1039/dt9960002911
日期:——
The reactions of chiral P,O-bidentate methyl 4,6-O-benzylidene-2-deoxy-2-(diphenylphosphino)-α-D-altropyranoside (HL1) and methyl 4,6-O-benzylidene-3-deoxy-3-(diphenylphosphino)-α-D-altropyranoside (HL2) with [PdCl2(cod)](cod = cycloocta-1,5-diene) or [PdCl2(NCMe)2] gave the complexes trans-[PdCl2(HL)2](L = L11a or L21b). Complex 1b crystallizes in the tetragonal space group P41212, with a= 12.326(2), c= 32.649(8)Å and Z= 4, R= 0.023 for 2502 reflections having I 3σ(I). The large deviation (14.6°) of the angle P–Pd–P′ from 180° may be ascribed to the overcrowding of the bulky phosphine ligands. Treatments of 1a and 1b with NaOMe in methanol gave the corresponding bis(alkoxo) complexes cis-[PdL2]2a and 2b. The compounds have been characterized by infrared, Raman, 1H, 13C and 31P NMR spectroscopy. The Pd–O absorption appears at 388 cm–1 for 2a and 366 cm–1 for 2b. The cis and trans geometries have been assigned by Raman spectroscopic studies.
手性 P,O-二叉甲基 4,6-O-亚苄基-2-脱氧-2-(二苯基膦)-α-D-阿托吡喃糖苷 (HL1) 和甲基 4、6-O-亚苄基-3-脱氧-3-(二苯基膦)-α-D-酰基吡喃糖苷(HL2)与[PdCl2(cod)](cod = 环辛烷-1,5-二烯)或[PdCl2(NCMe)2]反应,得到反式-[PdCl2(HL)2](L = L11a 或 L21b)络合物。配合物 1b 在四方空间群 P41212 中结晶,a= 12.326(2),c= 32.649(8)埃,Z= 4,2502 次反射的 R= 0.023,具有 I 3σ(I)。P-Pd-P′ 角与 180°的巨大偏差(14.6°)可能是由于笨重的膦配体过于拥挤所致。在甲醇中用 NaOMe 处理 1a 和 1b,可得到相应的双(烷氧基)配合物 cis-[PdL2]2a 和 2b。这些化合物通过红外光谱、拉曼光谱、1H、13C 和 31P NMR 光谱进行了表征。2a 和 2b 的 Pd-O 吸收分别出现在 388 cm-1 和 366 cm-1。拉曼光谱研究确定了顺式和反式几何结构。