A New Methodology for the Preparation of Cationic Organoplatinum(II) Complexes with Hydrogen-Bonding Functionality
摘要:
A new methodology for the preparation, of two series of cationic organoplatinum(II) complexes with hydrogen-bonding functionality is described. The mononuclear complexes of the type trans-[Pt(sigma -aryl)L(PPh3)(2)] OTf (L = nicotinic acid, aryl = C-3-benzoic acid (9) or C-4-benzoic acid (10); L = isonicotinic acid, aryl = C-3-benzoic acid (11) or C-4-benzoic acid (12); OTf = trifluoromethanesulfonate (triflate)) constitute the first series, and the dinuclear complexes of the type trans-[Pt(sigma -aryl)(PPh3)(2)(mu -L)Pt(sigma -aryl)(PPh3)(2)](OTf)(2) (L = 1,1-bis(4-pyridyl)ethene, aryl = C-3-benzoic acid (19) or C-4-benzoic acid (20); L = 4,7-phenanthroline, aryl = C-3-benzoic acid (21) or C-4-benzoic acid (22); L = 4,4 ' -bipyridine, aryl = C-3-benzoic acid (23) or C-4-benzoic acid (24)) constitute the second series. The methodology described here involves the protection of the carboxylic acid group of a 3- or 4-iodobenzoic acid precursor as the tert-butyldiphenylsilyl ester, followed by an oxidative addition reaction of the C-I bond with the Pt(0) species Pt(PPh3)4 to yield the key (sigma -aryl)iodoplatinum(II) intermediates 3 and 4, the structures of which were determined by X-ray crystallography. Subsequent treatment of these products with AgOTf, followed by the addition of a suitable monodentate or bridging bidentate N-donor ligand and, finally, facile removal of the silyl protecting group(s) with HOW affords the target complexes with hydrogen-bonding functionality in high yield. Variable-temperature H-1 NMR experiments with the silyl-protected complexes trans[Pt(sigma -aryl)L(PPh3)(2)]OTf (aryl = C-3-tert-butyldiphenylsilyl benzoate, L = nicotinic acid (5) or isonicotinic acid (7)) confirm that a dynamic intramolecular process involving the pyridyl ligand is occurring. The rotational barrier of a pyridyl ligand in an organoplatinum(II) complex is reported for the first time, where DeltaG(double dagger) = 48.3 +/- 0.9 and 45.7 +/- 0.9 kJ mol(-1) for complexes 5 and 7, respectively.
A New Methodology for the Preparation of Cationic Organoplatinum(II) Complexes with Hydrogen-Bonding Functionality
摘要:
A new methodology for the preparation, of two series of cationic organoplatinum(II) complexes with hydrogen-bonding functionality is described. The mononuclear complexes of the type trans-[Pt(sigma -aryl)L(PPh3)(2)] OTf (L = nicotinic acid, aryl = C-3-benzoic acid (9) or C-4-benzoic acid (10); L = isonicotinic acid, aryl = C-3-benzoic acid (11) or C-4-benzoic acid (12); OTf = trifluoromethanesulfonate (triflate)) constitute the first series, and the dinuclear complexes of the type trans-[Pt(sigma -aryl)(PPh3)(2)(mu -L)Pt(sigma -aryl)(PPh3)(2)](OTf)(2) (L = 1,1-bis(4-pyridyl)ethene, aryl = C-3-benzoic acid (19) or C-4-benzoic acid (20); L = 4,7-phenanthroline, aryl = C-3-benzoic acid (21) or C-4-benzoic acid (22); L = 4,4 ' -bipyridine, aryl = C-3-benzoic acid (23) or C-4-benzoic acid (24)) constitute the second series. The methodology described here involves the protection of the carboxylic acid group of a 3- or 4-iodobenzoic acid precursor as the tert-butyldiphenylsilyl ester, followed by an oxidative addition reaction of the C-I bond with the Pt(0) species Pt(PPh3)4 to yield the key (sigma -aryl)iodoplatinum(II) intermediates 3 and 4, the structures of which were determined by X-ray crystallography. Subsequent treatment of these products with AgOTf, followed by the addition of a suitable monodentate or bridging bidentate N-donor ligand and, finally, facile removal of the silyl protecting group(s) with HOW affords the target complexes with hydrogen-bonding functionality in high yield. Variable-temperature H-1 NMR experiments with the silyl-protected complexes trans[Pt(sigma -aryl)L(PPh3)(2)]OTf (aryl = C-3-tert-butyldiphenylsilyl benzoate, L = nicotinic acid (5) or isonicotinic acid (7)) confirm that a dynamic intramolecular process involving the pyridyl ligand is occurring. The rotational barrier of a pyridyl ligand in an organoplatinum(II) complex is reported for the first time, where DeltaG(double dagger) = 48.3 +/- 0.9 and 45.7 +/- 0.9 kJ mol(-1) for complexes 5 and 7, respectively.
Synthesis and redistribution reactions of asymmetric σ-arylplatinum(II) complexes containing 4,7-phenanthroline
作者:David P. Gallasch、Susan L. Woodhouse、Louis M. Rendina
DOI:10.1016/j.jorganchem.2004.01.027
日期:2004.4
The mononuclear σ-aryl complexes of the type trans-[Pt(σ-C6H4R)(4,7-phen)(PPh3)2]OTf (R=4-CO2SitBuPh2, 4-CONHMe, 3-CO2SitBuPh2, 3-CONHMe; OTf=trifluoromethanesulfonate) containing a monodentate 4,7-phenanthroline (4,7-phen) ligand were prepared by an oxidative addition reaction of an aryl iodide with Pt(PPh3)4 to yield the key iodoplatinum(II) precursors trans-[PtI(σ-C6H4R)(PPh3)2], followed by halogen
该类型的单核σ -芳基配合物的反式- [PT(σ-C 6 H ^ 4 R)(4,7-phen)的(PPH 3)2 ]光学传递函数(R = 4-CO 2的Si吨BUPH 2,4-通过芳基碘化物与Pt(PPh)的氧化加成反应制备含有单齿4,7-菲咯啉(4,7-phen)配体的CONHMe,3-CO 2 Si t BuPh 2,3 -CONHMe; OTf =三氟甲磺酸盐3)4得到关键的碘化铂(II)前体反式-[PtI(σ- C6 H 4 R)(PPh 3)2],然后进行卤素当量与一当量的4,7-phen置换。的反应反式[PT(σ-C - 6 ħ 4 R)(4,7-phen)的(PPH 3)2 ]光学传递函数与该类型的不稳定配合反式- [PT(OTF)L- 2(σ-C 6 H 4 R ')]](L = PEt 3,R ' = H; L = PPh 3,R ' = 4-CO 2 Si t BuPh
A New Methodology for the Preparation of Cationic Organoplatinum(II) Complexes with Hydrogen-Bonding Functionality
作者:David P. Gallasch、Edward R. T. Tiekink、Louis M. Rendina
DOI:10.1021/om010127c
日期:2001.8.1
A new methodology for the preparation, of two series of cationic organoplatinum(II) complexes with hydrogen-bonding functionality is described. The mononuclear complexes of the type trans-[Pt(sigma -aryl)L(PPh3)(2)] OTf (L = nicotinic acid, aryl = C-3-benzoic acid (9) or C-4-benzoic acid (10); L = isonicotinic acid, aryl = C-3-benzoic acid (11) or C-4-benzoic acid (12); OTf = trifluoromethanesulfonate (triflate)) constitute the first series, and the dinuclear complexes of the type trans-[Pt(sigma -aryl)(PPh3)(2)(mu -L)Pt(sigma -aryl)(PPh3)(2)](OTf)(2) (L = 1,1-bis(4-pyridyl)ethene, aryl = C-3-benzoic acid (19) or C-4-benzoic acid (20); L = 4,7-phenanthroline, aryl = C-3-benzoic acid (21) or C-4-benzoic acid (22); L = 4,4 ' -bipyridine, aryl = C-3-benzoic acid (23) or C-4-benzoic acid (24)) constitute the second series. The methodology described here involves the protection of the carboxylic acid group of a 3- or 4-iodobenzoic acid precursor as the tert-butyldiphenylsilyl ester, followed by an oxidative addition reaction of the C-I bond with the Pt(0) species Pt(PPh3)4 to yield the key (sigma -aryl)iodoplatinum(II) intermediates 3 and 4, the structures of which were determined by X-ray crystallography. Subsequent treatment of these products with AgOTf, followed by the addition of a suitable monodentate or bridging bidentate N-donor ligand and, finally, facile removal of the silyl protecting group(s) with HOW affords the target complexes with hydrogen-bonding functionality in high yield. Variable-temperature H-1 NMR experiments with the silyl-protected complexes trans[Pt(sigma -aryl)L(PPh3)(2)]OTf (aryl = C-3-tert-butyldiphenylsilyl benzoate, L = nicotinic acid (5) or isonicotinic acid (7)) confirm that a dynamic intramolecular process involving the pyridyl ligand is occurring. The rotational barrier of a pyridyl ligand in an organoplatinum(II) complex is reported for the first time, where DeltaG(double dagger) = 48.3 +/- 0.9 and 45.7 +/- 0.9 kJ mol(-1) for complexes 5 and 7, respectively.