OTHER PROPOSALS FOR WATER - BIPHASIC SYSTEMS

With the RCH/RP process, it is possible to hydroformylate propene up to pentenes with satisfying space time yields. On the other hand, heavier aldehydes such as Cio (iso-decanal) or higher from the hydroformylation of nonene(s), decenes, etc. can not be separated from the oxo catalysts by conventional means such as distillation due to thermal instability at the required temperatures and thus especially needs the careful aqueous-biphasic separation technique. There are numerous attempts to overcome the problem of low reactivity of higher alkenes which is due to low miscibility of the alkenes in water [26,27b, 50a,58d]. These proposals can briefly be summarized as  

Reactions take place at the water film - organic phase interface and are catalyzed by the phase-immobilized complex catalyst which is usually [HRh(CO)(TPPTS)3]. Other 

Advantageously, SAPC as a technique with immobilized catalysts does not need devices for catalyst separation and recycling, since the reactions can in principle be carried out using standard flow reactors commonly used in heterogeneous catalysis. On the other hand, the presumed processes for the work-up of the constituents of the catalyst, the ligand (and - may be - the support) will be demanding and expensive, too. 

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