71735-73-4Relevant academic research and scientific papers
Synthesis of fragrance compounds from renewable resources: The aqueous biphasic hydroformylation of acyclic terpenes
Vieira, Camila G.,De Freitas, Marina C.,De Oliveira, Kelley C. B.,De Camargo Faria, Amanda,Dos Santos, Eduardo N.,Gusevskaya, Elena V.
, p. 960 - 966 (2015)
The rhodium-catalyzed hydroformylation of acyclic terpenic compounds, i.e., β-citronellene, linalool and nerolidol, was performed in a water/toluene biphasic system. The addition of the cationic surfactant cetyltrimethylammonium chloride remarkably increased the reaction rates, with the surfactant effect being substrate dependent. A water-soluble phosphine ligand was used to immobilize the rhodium catalyst in water, an environmentally benign solvent, whereas non-polar products were collected in the organic phase. A complete phase separation was easily achieved by switching the magnetic stirrer off and cooling the mixture to room temperature. Linalool and nerolidol gave cyclic hemiacetals with excellent stereoselectivity, whereas the hydroformylation of β-citronellene resulted in two isomeric aldehydes with a linear-to-branched product ratio of approximately 85/15. Several fragrance compounds with pleasant sweet floral and woody scents were obtained in high yields through a simple and green one-pot procedure starting from the substrates easily available from natural bio-renewable resources.
Synthesis of fragrance compounds from acyclic monoterpenes: Rhodium catalyzed hydroformylation and tandem hydroformylation/acetalization of linalool and β-citronellene
Vieira, Camila G.,Dos Santos, Eduardo N.,Gusevskaya, Elena V.
, p. 208 - 215 (2013)
Rhodium-catalyzed hydroformylation of acyclic monoterpenic compounds, i.e., linalool and β-citronellene, was studied in toluene and ethanol solutions in the presence of PPh3 or P(O-o-tBuPh)3 ligands. Although both substrates have a monosubstituted terminal double bond, they show different behavior under the hydroformylation conditions. In toluene, linalool gave almost quantitatively a cyclic hemiacetal; whereas the hydroformylation of β-citronellene resulted in two isomeric aldehydes also in a nearly quantitative combined yield. The reactions occurred approximately two times faster in ethanol than in toluene giving the corresponding acetals even in the absence of additional acid co-catalysts. In the absence of phosphorous ligands, linalool (differently from β-citronellene) was very resistant to hydroformylation probably due to the binding with rhodium through both the double bond and the hydroxyl group to form stable chelates. The P(O-o-tBuPh)3 ligand exerted a remarkable effect on the reactivity of both substrates accelerating the reactions by 5-20 times as compared to the system with PPh3. Several fragrance compounds were obtained in high yields through a simple one-pot procedure starting from the substrates easily available from natural bio-renewable resources.
