Reaction of Cl2Si—CH2 3 with KFe CO 2cp

Reaction with (Cl2Si—CH2)3 is of particular interest because the products obtained still maintain active functional groups. The Si atoms bear two functional groups, so that as a result of nucleophilic attack sterically favored positions on this ring can be selected. The reaction of (C Si—CH2)3 with 1 mole equivalent of KFe(CO)2cp in unpolar solvents generated compound 3M, which was isolated in the form of light yellow crystals of mp. 113 °C. The side reactions observed frequently in etheral solvents did not occur. 

The reaction performed with a mole ratio of 1 2 in methylcyclohexane yielded similarly 384. In the more polar solvent THF, the tendency for the metal carbonylate to cause nucleophilic attack increases to such an extent, that a two-fold substitution generated 385, which was isolated in the form of yellow crystals with mp. 134-136 °C. 

381 white amorphous substances 382 yellow squared crystals 164-166 19% in THF 13% 

The investigations described so far indicate that reactions of metal carbonylates in general lead only to the coordination of two metal carbonyl groups to the 1,3,5-trisilacyclohexanes. From the chemistry of silylcobalt compounds it is known that silanes of the type R SiH (n = 1-3) cleave dinuclear Co2(CO)g, producing silyl-cobalt-carbonyl complexes [166, 167, 171]. 

Utilizing the method just described, higher metal-carbonyl-substituted 1,3,5-trisilacyclohexanes can be achieved, as the reactions of compounds 3, 379 and 376 with Co2(CO)8 show [163]. 

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