Platinum complexes Grignard reagents

As is shown below for some platinum complexes, organolithiiun reagents are more reactive than Grignard rea nts, and yield fully alkylated or arylated products more readily ... 

Cyano compounds liquid crystals, 12, 278 in silver(III) complexes, 2, 241 Cyanocuprates, with copper, 2, 186 Cyano derivatives, a-arylation, 1, 361 Cyanosilanes, applications, 9, 322 Cyclic acetals, and Grignard reagent reactivity, 9, 53 Cyclic alkenes, asymmetric hydrosilylation, 10, 830 Cyclic alkynes, strained, with platinum, 8, 644 Cyclic allyl boronates, preparation, 9, 196 Cyclic allylic esters, alkylation, 11, 91 Cyclic amides, ring-opening polymerization, via lanthanide catalysis, 4, 145... 

E = As, Sb or Bi) react similarly with Grignard reagents, providing routes to cyclic arsines, stibines and bismuthines. Leung s group has reported further applications of asymmetric Diels-Alder cyclisation reactions in phosphine synthesis. A platinum complex chiral auxiliary has been used to promote the asymmetric [4-1-2] Diels-Alder addition of diphenyl(vinyl)-phosphine to 3-diphenylphosphinofuran, giving the eradocycloadduct (70) as the predominant stereoisomer. Related cycloadditions between 3,4-dimethyl-1 -phenylphosphole and ester-functionalised allylic phosphines have provided chemoselective routes to optically-pure P-chiral 1,2- and... 

A mixture of p-fluorophenylmagnesium bromide, /7-methoxyphenylethenyl bromide, and 2 mol% Pt-rj -alkene complex (prepared by reacting dichloro[l,T-bis(diphenyl-phosphino)ferrocene]platinum(II) with /7-methoxyphenylethenyl bromide in THF at room temp.) in THF refluxed for 2 days - product. Y 95%. This is the first report of efficient Pt-catalyzed cross-coupling with Grignard reagents. F.e.s. J.M. Brown et al., J. Chem. Soc. Chem. Commun. 1989, 458-60. 

While the Grignard reagent effects only mono-substitution at platinum, the more reactive lithium compound yields the dimethyl derivative. Use of mild alkylating agents can sometimes be used to advantage to give partial substitution. This is illustrated by the methyltitanium system. The very low thermal stability of some of these complexes should be noted. 

Nickel and platinum mediated allylation reactions have been reported and in terms of AAA reactions, perhaps the most useful processes have involved hard nucleophiles. For example, high enantioselectivities have been realized in nickel-catalyzed processes employing Grignard reagents. Tungsten has also been used in Tsuji-Trost type reactions, however it has thus far not been applied to complex molecule synthesis. ... 

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