Metathesis in Ionic Liquids
Publication Date: 2004-Jan-06
The IP.com Prior Art Database
Callie v Biljon, DM Kisch Patent Attorneys: ATTORNEY [+4]
The invention relates to a metathesis reaction between at least two olefinic compounds which are the same or different, each olefinic compound comprising a non-cyclic olefin or a compound which includes a non-cyclic olefinic moeity; the metathesis reaction being carried out in the presence of a Ru-based metathesis reaction catalyst; and the metathesis reaction further being carried out in the presence of an ionic liquid.
FIELD OF THE INVENTION
This invention relates to the use of ionic liquids in a metathesis reaction between at least two olefins which are the same or different.
Olefinic metathesis reactions are well known in the art. The quest for highly active olefin metathesis catalysts has prompted considerable research efforts to develop olefin metathesis systems capable of tolerating a variety of functional groups. Ruthenium-based catalysts in particular have proven to be useful in catalysing olefin metathesis reactions, including cross metathesis(CM), ring-closing metathesis (RCM) and ring-opening metathesis polymerisation (ROMP) reactions.
Olefin metathesis refers to the metal-catalysed redistribution of carbon-carbon double bonds. CM can be described as a metathesis reaction between two non-cyclic olefins, which may be the same or different, for example:
Where the olefins are the same, the reaction is known as self metathesis.
ROMP is a variant of olefin metathesis reactions wherein cyclic olefins produce polymers and co-polymers, for example:
RCM represents a process in which an acyclic diene is cyclised to produce a cycloalkene, for example;
As indicated above metathesis reactions take place in the presence of a catalyst. Grubbs-type catalysts are ruthenium alkylidene complexes and are highly active single component pre-catalysts for alkene metathesis reactions.
Ionic liquids are salts (consisting of an anion and cation), which are liquids at or near the reaction temperature, or exists in a fluid state during any stage of the reaction. The use of ionic liquids in combination with olefinic metathesis reactions and/or other reactions are known and have been referred to in (i) WO 00/20115; (ii) US 6,284,937; (iii) US 5,675,051; (iv) US 5,525,567; (v) US Publication No. 2001/0005494; (vi) Organic letters 2001 Vol 3 (23) page 3785 –3787; (vii) Organic letters 2002 Vol 4 (9) page 1567 –1570; (viii) Chemical Comm, 2002, 146 – 147; (ix) JACS, 2003, 125, page 9248-9249 and (x); Angew. Chem., 2003, 115, page 3517-3520.
The present invention is distinguished over the above disclosures since the above disclosures relate to RCM reactions; and/or monophasic reactions, and/or to the use of certain catalysts which are different to the catalysts of the present invention.
The present invention does not relate to RCM reactions but to cross or self metathesis reactions between at least two olefins which are the same or different. In this type of reaction the selectivity of the process plays a very important role and typical side reactions such as isomerisation and secondary metathesis product formation must be minimised in order to enhance the production of the primary metathesis product. This further distinguishes the invention over the prior art, where no improvement in reaction selectivities in the presence of ionic liquids is reported.
In the case of monophasic metathesis reactions using ionic liquids the catalyst and reactants are in the same...