Platinum organometallic complexes

A review9 with more than 37 references includes an examination of symmetry groups and chirality conditions for C60 and C70 bonded to one or two metals in rf and/or rf fashion. Palladium and platinum rf complexes of C6o and C70 are described (novel synthesis, NMR spectra, electrochemistry) as well as first optically active organometallic fullerene derivatives. 

The Cossee mechanism has been demonstrated by direct observation of organometallic complexes where a C = C bond inserts itself into an M-C bond as shown in Eq. (7)-(9). A labeling experiment on a cationic platinum complex 111 indicated the reversible insertion of the coordinated alkene into the Pt-C bond as shown in Eq. (7) [142]. 

Numerous studies aimed at the understanding of the mechanism of these processes rapidly appeared. In this context, Murai examined the behavior of acyclic linear dienyne systems in order to trap any carbenoid intermediate by a pendant olefin (Scheme 82).302 A remarkable tetracyclic assembly took place and gave the unprecedented tetracyclo[6.4.0.0]-undecane derivatives as single diastereomer, such as 321 in Scheme 82. This transformation proved to be relatively general as shown by the variation of the starting materials. The reaction can be catalyzed by different organometallic complexes of the group 8-10 elements (ruthenium, rhodium, iridium, and platinum). Formally, this reaction involves two cyclopropanations as if both carbon atoms of the alkyne moiety have acted as carbenes, which results in the formation of four carbon-carbon bonds. 

This section on platinum carbonyl complexes should be read in conjunction with the comparable chapter by Hartley in Comprehensive Organometallic Chemistry , Volume 6, Chapter 39. This section will emphasize very recent work and will omit compounds which are completely organometallic in nature. 

The structures of platinum(O) complexes of alkynes are fully summarized in Chapter 39 of Comprehensive Organometallic Chemistry and need not be covered here. 

Organom etallic Compounds. Organometallic complexes of platinum are usually more stable than palladium complexes. Carbon monoxide complexes of platinum are formed more readily than with palladium. Mononuclear and polynuclear complexes in oxidation states 0 to +2 exist such as... 

Electron-rich, unsaturated hydrocarbons, which are normally resistant to nucleophilic attack, become generally reactive towards nucleophiles upon complexation to an electrophilic transition metal such as palladium(II), platinum(II) or iron(II). Complexation also directs the regio- and stereo-chemistry of the nucleophilic attack, the result of which is a new organometallic complex, which can often be used to promote additional functionalization of the original substrate. Synthetically useful examples of such processes are presented in the following sections. 

Bis(phosphoranimine) ligands, chromium complexes, 5, 359 Bis(pinacolato)diboranes activated alkene additions, 10, 731—732 for alkyl group functionalization, 10, 110 alkyne additions, 10, 728 allene additions, 10, 730 carbenoid additions, 10, 733 diazoalkane additions, 10, 733 imine additions, 10, 733 methylenecyclopropane additions, 10, 733 Bisporphyrins, in organometallic synthesis, 1, 71 Bis(pyrazol-l-yl)borane acetyl complexes, with iron, 6, 88 Bis(pyrazolyl)borates, in platinum(II) complexes, 8, 503 Bispyrazolyl-methane rhodium complex, preparation, 7, 185 Bis(pyrazolyl)methanes, in platinum(II) complexes, 8, 503 Bis(3-pyrazolyl)nickel complexes, preparation, 8, 80-81 Bis(2-pyridyl)amines... 

PNA, bioorganometallic studies, 1, 902 P2N2 dianionic macrocycle, in organometallic synthesis, 1, 69 7yV,P-tridentate ligands, in platinum(II) complexes, 8, 537 Pockels effect, and second-order non-linear polarization,... 

Osakada, K. Hamada, M. Yamamoto, T. Inter-molecular alkynyl ligand transfer in Pd(II) and platinum(II) complexes with CCC02R and CCPh ligands. Relative stability of the alkynyl complexes and conproportionation of dialky-nyl and diiodo complexes of these metals. Organometallics 2000, 19, 458—468. 

Ruiz J, Lorenzo J, Sanglas L, Cutillas N, Vicente C, Villa MD, Aviles FX, Lopez G, Moreno V, Perez J, Bautista D (2006) Palladium(II) and platinum(II) organometallic complexes with the model nucleobase anions of thymine, uracil, and cytosine antitumor activity and interactions with DNA of the platinum compounds. Inorg Chem 45 6347-6360... 

Ruiz J, Villa MD, Cutillas N, Lopez G, de Haro C, Bautista D, Moreno V, Valencia L (2008) Palladium(II) and Platinum(II) Organometallic Complexes with 4, 7-dihydro-5-methyl-7-oxo[l, 2, 4]triazolo[l, 5-a]pyrimidine. Antitumor activity of the platinum compounds. Inorg Chem 47 4490 1505... 

Casini A, Gabbiani C, Michelucci E, Pieraccini G, Moneti G, Dyson PJ, Messori L (2009) Exploring metallodrug-protein interactions by mass spectrometry comparisons between platinum coordination complexes and an organometallic ruthenium compound. J Biol Inorg Chem 14 761-770... 

Fig. 10. Diagrams of the platinum halogenomethyl complexes prepared by McCrindle et al. [Adapted with permission from the American Chemical Society and the Royal Society of Chemistry from R. McCrindle, G. Ferguson, G. J. Arsenault, A. J. McAlees, B. L. Ruhl, and D. W. Sneedon, Organometallics 5, 1171 (1986) R. McCrindle, G. J. Arsenault, R. Farwaha, M. J. Hampden-Smith, R. E. Rice, and A. McAlees, J. Chem. Soc., Dalton Trans., 1773 (1988).]...

Recent structural and spectroscopic investigations of organometallic complexes bonding two carbons of an allenic ligand to one rhodium 50 72> 87,95) or platinum atom 58,87,98,132) may have some pertinence to possible bridged intermediates proposed for various electrophilic additions to allenes, and the cr-iron-jr-iron complexes derived from allene and diiron... 

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