Preparation, structures, and thermal reactivity of alkoxycarbonyl(cyano) palladium(II) complexes trans-Pd(COOR)(CN)(PPh3)2 (R = Me, Et, nPr, iPr, nBu, tBu, and Bn) as intermediates of the palladium-catalyzed cyanoesterification of norbornene derivatives
Preparation, structures, and thermal reactivity of alkoxycarbonyl(cyano) palladium(II) complexes trans-Pd(COOR)(CN)(PPh3)2 (R = Me, Et, nPr, iPr, nBu, tBu, and Bn) as intermediates of the palladium-catalyzed cyanoesterification of norbornene derivatives
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DOI：
10.1021/om700343y
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发表时间：
2007-06
期刊：
影响因子：
2.8
通讯作者：
Y. Nishihara;M. Miyasaka;Y. Inoue;Tomoka Yamaguchi;M. Kojima;K. Takagi
中科院分区：
文献类型：
--
作者：
Y. Nishihara;M. Miyasaka;Y. Inoue;Tomoka Yamaguchi;M. Kojima;K. Takagi
烷氧基羰基（氰基）钯（II）配合物trans-Pd（COOR）（CN）（PPh 3）2（1，R = Me; 2，R = Et; 3，R = nPr; 4，R = iPr; 5，R = nBu; 6，R = tBu; 7，R = Bn）通过在室温或50 ℃下在甲苯中将相应的氰基甲酸酯氧化加成到Pd（PPh 3）4上来制备，并通过NMR进行表征（1H、13 C {1H}和31 P {1H}）和IR光谱以及元素分析。3、4和6的X-射线晶体学显示了Pd中心周围的正方形平面配位，其以反式构型与烷氧基羰基和氰基配体键合。1、3、4和6中的Pd-CN和Pd-COOR键与迄今报道的氰基钯（II）和烷氧基羰基钯（II）配合物中的类似。在Pd（PPh 3）4与氰基甲酸苯酯反应时，发生热诱导配体交换，得到双氰基钯（II）络合物，trans-Pd（CN）2（PPh 3）2（8）。配合物2能催化降冰片二烯与氰基甲酸乙酯反应生成（2 R *，3S*）-乙基3-氰基双环[2.2.1]庚-2-烯。
Alkoxycarbonyl(cyano)palladium(II) complexes trans-Pd(COOR)(CN)(PPh3)2 (1, R = Me; 2, R = Et; 3, R = nPr; 4, R = iPr; 5, R = nBu; 6, R = tBu; 7, R = Bn) are prepared via oxidative addition of the corresponding cyanoformates to Pd(PPh3)4 in toluene at room temperature or 50 °C and characterized by means of NMR (1H, 13C{1H}, and 31P{1H}) and IR spectroscopy as well as elemental analyses. X-ray crystallography of 3, 4, and 6 showed a square-planar coordination around the Pd center that is bonded to alkoxycarbonyl and cyano ligands in the trans configuration. The Pd−CN and Pd−COOR bonds in 1, 3, 4, and 6 are similar to those of the cyanopalladium(II) and alkoxycarbonylpalladium(II) complexes reported to date. On reaction of Pd(PPh3)4 with phenyl cyanoformate a thermally induced ligand exchange takes place to afford the dicyanopalladium(II) complex, trans-Pd(CN)2(PPh3)2 (8). Complex 2 is able to catalyze the reaction of norbornadiene with ethyl cyanoformate to produce (2R*,3S*)-ethyl 3-cyanobicyclo[2.2.1]hept-...