945722-82-7Relevant academic research and scientific papers
Ruthenium-catalyzed redox isomerization/transfer hydrogenation in organic and aqueous media: A one-pot tandem process for the reduction of allylic alcohols
Cadierno, Victorio,Crochet, Pascale,Francos, Javier,Garcia-Garrido, Sergio E.,Gimeno, Jose,Nebra, Noel
scheme or table, p. 1992 - 2000 (2010/06/19)
The hexamethylbenzene-ruthenium(ii) dimer [{RuCl(μ-Cl) (η6-C6Me6)}2] 1 and the mononuclear bis(allyl)-ruthenium(iv) complex [RuCl2(η 3:η2:η3-C12H 18)]2, associated with base and a hydrogen donor, were found to be active catalysts for the selective reduction of the CC bond of allylic alcohols both in organic and aqueous media. The process, which proceeds in a one-pot manner, involves a sequence of two independent reactions: (i) the initial redox-isomerization of the allylic alcohol, and (ii) subsequent transfer hydrogenation of the resulting carbonyl compound. The highly efficient transformation reported herein represents, not only an illustrative example of auto-tandem catalysis, but also an appealing alternative to the classical transition-metal catalyzed CC hydrogenations of allylic alcohols. The process has been successfully applied to aromatic as well as aliphatic substrates affording the corresponding saturated alcohols in 45-100% yields after 1.5-24 h. The best performances were reached using (i) 1-5 mol% of 1 or 2, 2-10 mol% of Cs2CO3, and propan-2-ol or (ii) 1-5 mol% of 1 or 2, 10-15 equivalents of NaO2CH, and water. The catalytic efficiency is strongly related to the structure of the allylic alcohol employed. Thus, in propan-2-ol, the reaction rate essentially depends on the steric requirement around the CC bond, therefore decreasing with the increasing number of substituents. On other hand, in water the transformation is favoured for primary allylic alcohols vs. secondary ones.
Ruthenium-catalyzed reduction of allylic alcohols: An efficient isomerization/transfer hydrogenation tandem process
Cadierno, Victorio,Francos, Javier,Gimeno, Jose,Nebra, Noel
, p. 2536 - 2538 (2008/02/11)
A simple and highly efficient method for the selective reduction of the C=C bond in allylic alcohols has been developed using the ruthenium(ii) catalyst [{RuCl(μ-Cl)(η6-C6Me6)}2]. The Royal Society of Chemistry.
Application of A Recyclable Pseudoephedrine Resin in Asymmetric Alkylations on Solid Phase
Hutchison, Panee C.,Heightman, Tom D.,Procter, David J.
, p. 790 - 801 (2007/10/03)
A pseudoephedrine resin has been successfully employed in asymmetric alkylations on solid phase. Immobilized pseudoephedrine amides are conveniently prepared by the one-step attachment of pseudoephedrine to Merrifield resin through the hydroxyl group and subsequent acylation on nitrogen. Deprotonation and alkylation of the resin-bound amides proceeds smoothly. Ketones and alcohols are cleaved from the resin in high enantiomeric excess and moderate to good overall yield. The parallel, asymmetric solid-phase synthesis of a small library of chiral ketones and alcohols has been carried out to illustrate the utility of the approach. Finally, the pseudoephedrine resin can be conveniently recycled and utilized with no significant loss in the yield or enantiomeric excess of the products.
