Tetraphenylcyclopentadienone, conversion

Although the reactions between alkynes or alkenes and metal clusters are the main source of alkyne-substituted complexes, there are other reagents which can produce similar products. Two such reagents are tetraphenylcyclopentadienone, which in the reaction with Ru3(CO)i2 produces Ru3(CO)10(PhCCPh) (167), and dimethyl-vinylarsine, which has been made to react with several carbonyl clusters [Eq. (8)] (168, 169). In the reaction of M3(CO)12 (M = Ru, Os) with a number of tertiary phosphines and aromatic alcohols, an oxidative addition takes place and benzyne-triosmium compounds are obtained (170-176). The fact that Os3(CO)uPEt3 can be converted into an alkyne compound (177) suggests that the conversion goes through substituted intermediates. Carbene derivatives of clusters have also... 

Tetraphenylcyclopentadiene. This useful diene (2) is not easily available, although tetraphenylcyclopentadienone (1, tetracyclone) is prepared readily (1, 1149). An early study1 of conversion of (1) into (2) by reduction was not particularly promising, the best yield (18%) being obtained by inverse lithium... 

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