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DOI: 10.1055/s-0030-1260800
Cobalt(I)-Catalysed Reactions for the Synthesis of Acyclic 1,4-Dienes - Genesis of Two Synthetic Methods
Publikationsverlauf
Received
23 February 2011
Publikationsdatum:
21. Juni 2011 (online)
Abstract
The search for atom-economic carbon-carbon bond-forming reactions initiated by low-valent cobalt complexes has led to two reactions that generate acyclic 1,4-dienes: the 1,4-hydrovinylation reaction of a terminal alkene with a 1,3-diene and the Alder-ene reaction of a terminal alkene with an internal alkyne.
The regioselective cobalt-catalysed Diels-Alder reaction of an alkyne and a 1,3-diene for the synthesis of cyclic 1,4-dienes led to its application in the synthesis of 1,3-dicarbonyl derivatives upon ozonolysis. Through applications of the cobalt-catalysed 1,4-hydrovinylation reaction, the synthesis of 1,3- or 1,4-dicarbonyl derivatives can be accomplished in a substrate-controlled process. For instance, 2,3-dimethylbuta-1,3-diene leads to acyclic 1,4-dienes via the cobalt-catalysed 1,4-hydrovinylation reaction which can then be converted into 1,3-carbonyls by ozonolysis. In contrast, the use of 2-(trimethylsiloxy)buta-1,3-diene generates γ,δ-unsaturated ketones, which can be converted into 1,4-dicarbonyl derivatives upon ozonolysis. Recently, studies into the synthesis of different types of polycarbonyl compounds in which the distance between the carbonyl groups can be altered have been initiated.
1 Introduction
2 The 1,4-Hydrovinylation Reaction
3 The Alder-ene Reaction
4 Stoking the Fire of the Hydrovinylation Reaction
5 The ‘Second Generation’ of 1,4-Hydrovinylation Processes
Key words
Alder-ene reactions - alkenes - alkynes - cobalt catalysis - dienes - hydrovinylations