There is interest in dendritic molecules, i.e. those with branched arms that diverge from a central core.

Question:

There is interest in ‘dendritic’ molecules, i.e. those with ‘branched arms’ that diverge from a central core. The supported dendritic catalyst 25.38 can be used in hydroformylation reactions, and shows high selectivity for branched over linear aldehyde products.

(a) Is 25.38 likely to be the active catalytic species? Rationalize your answer.

(b) What advantages does 25.38 have over a mononuclear hydroformylation catalyst such as HRh(CO)₂(PPh₃)₂?

(c) Give a general scheme for the hydroformylation of pent-1-ene (ignoring intermediates in the catalytic cycle) and explain what is meant by ‘selectivity for branched over linear aldehyde products’.