Functionalised olefins

The Mizoroki-Heck reaction is a metal catalysed transformation that involves the reaction of a non-functionalised olefin with an aryl or alkenyl group to yield a more substituted aUcene [11,12]. The reaction mechanism is described as a sequence of oxidative addition of the catalytic active species to an aryl halide, coordination of the alkene and migratory insertion, P-hydride elimination, and final reductive elimination of the hydride, facilitated by a base, to regenerate the active species and complete the catalytic cycle (Scheme 6.5). 

MTO supported on acidic metal oxides was quickly discovered to form metathesis catalysts that are active without the need for additives, even for functionalised olefins [70]. Standard supports are zeolites and niobia (Nb205), and the activity was reported to be related to the surface acidity [79]. 

Hydroformylation of Functionalised Olefins - Introduction of polar substituents such as -C02Me into the alkyl chain of a-olefins considerably extends the scope of Rh/tppts-catalysed hydroformylation in aqueous/organic two phase systems.89,417... 

In conclusion, chiral heterogeneous catalysts are prepared from chiral Rhodium diphosphine complexes and Al-MCM-41. The bonding supposedly occurs via an ionic interaction of the cationic complex with the host. Also a slight reduction of weak acidic sites of Al-MCM-41 has been observed. These catalysts are suitable for the hydrogenation of functionalised olefins. The organometallic complexes remain stable within the mesopores of the carrier at reaction conditions. The catalyst can be recycled by filtration or centrifugation. 

Conditions Lauroyi peroxide (2-10 moi%), 1,2-dichloroethane, reflux Scheme 3 Examples of radical addition to variously functionalised olefins... 

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