Platinum complex carborane

The double silylation of unsaturated organic compounds catalyzed by group 10 metals is a convenient synthetic route to disilacyclic compounds. Nickel and platinum complexes, in particular, are excellent catalysts for the transformation of disilanes. Cyclic bis(silyl)metal complexes2,3 have been implicated as key intermediates in the metal-catalyzed double silylation of alkynes, alkenes, and aldehydes however, the intermediates have not been isolated due to their instability. We now describe (i) the isolation of the reactive intermediates cyclic bis(silyl)metal compounds (1) with bulky o-carborane unit 4 (ii) the generation of a new class of heterocyclic compounds (4-5) by the stoichiometric reaction of the intermediates with a variety of substrates such as an alkyne, dione, and nitrile 4 and (iii) the facile double silylation of alkenes and alkynes (10,12-14) catalyzed by the intermediate under mild conditions.5... 

Recently, some other boron carriers were used to deliver polyhedral boranes into tumor cells. One of the most interesting and new direction is developments in the BNCT driven by nanotechnology [142-147]. This subject will not be discussed here since a special chapter is planned in this book. Carboranylquinazolines [148], carboranyl aminoalcohols [149], carboranyl-a-acyloxy-amides [150], carboranyl glycophosphonates [151], conjugates of icosahedral dicarboranes with cobalt bis(dicarbollide) [152], and platinum complexes containing carborane [153] have been obtained as potential candidates for BNCT. 

J. Yoo, Y. Do. Synthesis of stable platinum complexes containing carborane in a carrier group for potential BNCT agents. Dalton Trans., 2009,4978-4986. 

Table 3. ICso (jiM) values for some platinum(II) carborane complexes against selected tumor cell lines...

Using metathetical replacement, cis- and frans-hydridocarborane complexes PtH(o-carborane) [L = PEt3, PPh3, PPh2Me, PPhMe2 carborane = 2-R-l,2- or 7-R-1,7-B10C2Hm (R = H, Me, Ph)] have been prepared.101 The cis complexes are the first examples of neutral as-monohydrido platinum(II) complexes with a Pt—C o bond. 

A number of reactions of platinum(O) complexes have been discussed in the earlier sections of this chapter. These reactions include protonation reactions of PtL3 to give PtHLJ, oxidative addition of HX to give PtHXL, replacement with carboranes, alkenes and alkynes (L1) to give complexes of type PtLjL. The most studied complex of platinum(O) is Pt(PPh3)3 and in Scheme 10 are outlined examples of the numerous reactions which this compound will undergo. 

Dimethyl bis-benzamidinato complex, with Ti(IV), 4, 344 Dimethyl carboranes, with tantalum, 5, 163 Dimethyl complexes with cadmium, 2, 464 with nickel, 8, 58-59 with platinum(II), 8, 460 with titanium(IV), 4, 331, 4, 343 Dimethyl diallylmalonate, cyclization-hydrosilylation, 11, 385 Dimethyl diamido complexes, with Ti(IV), 4, 332... 

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