Domino Reactions with Ru Catalysts

Tandem or domino reactions using hydroformylation as the first step allow the immediate transformation of the formed aldehydes into other valuable chemical compounds (see Chapter 5) [41]. As discussed previously, the hydrogenation of olefinic substrates or product aldehydes is a commonly observed side reaction in the hydroformylation with Ru complexes. On the other hand, the reduction of the aldehydes can be desired. 

Bell and coworkers showed that both reactions can be mediated by the same Ru catalyst in a one-pot manner. It may be advantageous to adapt the conditions to each reaction. In order to draw benefit from the whole hydrogenation activity of a RuCl2(PPhg)3 catalyst, removal of traces of CO was mandatory [42]. Thus it was found that in the batch hydroformylation of 1-hexene with stoichiometric amount of carbon monoxide, the residual CO poisoned the Ru catalyst. Only utilization of sub-stoichiometric quantities of CO and a conversion of nearly 100% or venting the hydroformylation gases allowed the subsequent efficient hydrogenation. 

1 -pentene, cyclohexene, styrene, 3-phenylpropene, isoprene, methyl a-methylacrylate... 

121-146 (b) Mitsudo, T. and Kondo, T. (2004) in Ruthenium in Organic Synthesis (ed S.-I. Murahashi), tX41ey-VCH Verlag GmbH, Weinheim, 

Jennerjahn, R, Jackstell, R., Spannenberg, A., Franke, R., and Beller, M. (2011) Angew. Chem. Int. 

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