2385-77-5Relevant articles and documents
Synthesis of Citronellal by RhI-Catalysed Asymmetric Isomerization of N,N-Diethyl-Substituted Geranyl- and Nerylamines or Geraniol and Nerol in the Presence of Chiral Diphosphino Ligands, under Homogeneous and Supported Conditions
Chapuis, Christian,Barthe, Michel,Laumer, Jean-Yves de Saint
, p. 230 - 242 (2001)
For the asymmetric isomerization of geranyl- or neryldiethylamine (( E)- or(Z)-1, resp.) and allyl alcohols geraniol or nerol ((E)- or (Z)-2, resp.) to citronellal (4) in the presence of a [RhI(ligand)cycloocta-1,5-diene)]- catalyst, the atropic ligands 5-11 are compared under homogeneous and polymer-supported conditions with the non-C2-symmetrical diphosphino ferrocene ligands 12-16. The tBu-josiphos ligand 13 or daniphos ligand 19, available in both antipodal series, already catalyse the reaction of (E)-1 at 20 deg (97 percent e.e.) and favourably compare with the binap ligand 5 (see Table 1). Silica-gel- or polymer-supported diphosphino ligands usually afford similar selectivity as compared to the corresponding ligands applied under homogeneous conditions, but are generally less reactive. In this context, a polymer-supported ligand of interest is the polymer-anchored binap (R)-6, in terms of reactivity, selectivity, and recoverability, with a turnover of more than 14400.
Asymmetric cleavage of chiral α,β-ethylenic acetals by organolithium reagents
Alexakis, Alexandre,Mhamdi, Farida,Lagasse, Franz,Mangeney, Pierre
, p. 3343 - 3346 (1996)
,β-Ethylenic chiral acetals react regio- and stereoselectively with organolithium reagents. The obtained enol ether may be hydrolyzed into a chiral β-disubstituted aldehyde.
Multicatalytic approach to one-pot stereoselective synthesis of secondary benzylic alcohols
Casnati, Alessandra,Lichosyt, Dawid,Lainer, Bruno,Veth, Lukas,Dydio, Pawe?
supporting information, p. 3502 - 3506 (2021/05/10)
One-pot procedures bear the potential to rapidly build up molecular complexity without isolation and purification of consecutive intermediates. Here, we report multicatalytic protocols that convert alkenes, unsaturated aliphatic alcohols, and aryl boronic acids into secondary benzylic alcohols with high stereoselectivities (typically >95:5 er) under sequential catalysis that integrates alkene cross-metathesis, isomerization, and nucleophilic addition. Prochiral allylic alcohols can be converted to any stereoisomer of the product with high stereoselectivity (>98:2 er, >20:1 dr).
Method for preparing optically active citronellal and catalyst system for method
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Paragraph 0071-0085, (2020/05/05)
The invention provides a method for preparing optically active citronellal and a catalyst system for the method. The method comprises the step that in the presence of a catalyst, neryl aldehyde shownin the formula (I) and/or geranial shown in the formula (II) are/is subjected to asymmetric hydrogenation to prepare optically active R-citronellal shown in the formula (III), and the catalyst comprises rhodium serving as a catalytic activity transition metal, a chiral bidentate diphosphine ligand and TiO2-loaded activated carbon. According to the method, the stereoselectivity of the reaction canbe remarkably improved, and the R-citronellal with high optical purity is obtained.