Please use this identifier to cite or link to this item: http://hdl.handle.net/10316/5010
Title: Rhodium catalyzed hydroformylation of kaurane derivatives: A route to new diterpenes with potential bioactivity
Authors: Peixoto, Andreia F. 
Melo, Daniela S. de 
Fernandes, Tânia F. 
Fonseca, Yuraima 
Gusevskaya, Elena V. 
Silva, Artur M. S. 
Contreras, Ricardo R. 
Reyes, Marisela 
Usubillaga, Alfredo 
Santos, Eduardo N. dos 
Pereira, Mariette M. 
Bayón, J. Carles 
Keywords: Diterpenes; Kauranes; Hydroformylation; Rhodium; Phosphite; Phosphine
Issue Date: 2008
Citation: Applied Catalysis A: General. 340:2 (2008) 212-219
Abstract: Kaurenic and grandiflorenic acids are naturally occurring diterpenes whose biological activity has been described. Both acids contain an exocyclic methylenic double bond that allows further functionalization on their structure. In an attempt to expand the number of derivatives of these two natural products, we have undertaken a study on the hydroformylation of the methyl esters of the two acids and the trimethylsilyl ether of kaurenol. These substrates have been hydroformylated by using unmodified Rh catalysts, as well as Rh/PPh3 and Rh/tris-(o-t-butylphenyl)phosphite catalytic systems at 100 °C and 20 bar of CO/H2 (1:1). For the three substrates, the two Rh catalysts modified with P-donor ligands, produced high conversions and chemo- and regioselectivities in the diastereoisomeric pair of linear aldehydes. In all cases, the stereoselectivity observed is strongly dependent of the system used, being the most diastereoselective the least hindered unmodified Rh/CO catalyst. A correlation between the higher diastereoselectivity and the faster [beta]-elimination of the metal-alkyl intermediate observed in the unmodified system is discussed.
URI: http://hdl.handle.net/10316/5010
Rights: openAccess
Appears in Collections:FCTUC Química - Artigos em Revistas Internacionais

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