137623-80-4Relevant academic research and scientific papers
Iridium-Catalyzed Asymmetric Isomerization of Primary Allylic Alcohols Using MaxPHOX Ligands: Experimental and Theoretical Study
Cabré, Albert,Gar?on, Martí,Gallen, Albert,Grisoni, Lorenzo,Grabulosa, Arnald,Verdaguer, Xavier,Riera, Antoni
, p. 4112 - 4120 (2020/07/04)
The asymmetric isomerization of primary allylic alcohols to chiral aldehydes using iridium-catalysts bearing P,N-MaxPHOX ligands has been studied. These catalysts can be fine-tuned as they present three different stereogenic centers to modulate both the reactivity and enantioselectivity of a family of different substrates. The experimental part is supported by a DFT study of the reaction mechanism, which provides new insights into the key steps of this transformation.
Direct Stereoselective Installation of Alkyl Fragments at the β-Carbon of Enals via Excited Iminium Ion Catalysis
Verrier, Charlie,Alandini, Nurtalya,Pezzetta, Cristofer,Moliterno, Mauro,Buzzetti, Luca,Hepburn, Hamish B.,Vega-Pe?aloza, Alberto,Silvi, Mattia,Melchiorre, Paolo
, p. 1062 - 1066 (2018/02/14)
The direct introduction of sp3 carbon fragments at the β position of α,β-unsaturated aldehydes is greatly complicated by competing 1,2-addition manifolds. Previous catalytic enantioselective conjugate addition methods, based on the use of organometallic reagents or ground-state iminium ion activation, could not provide general and efficient solutions. We report herein that, by turning them into strong oxidants, visible light excitation of chiral iminium ions triggers a stereocontrolled radical pathway that exclusively affords highly enantioenriched β-substituted aldehydes bearing a variety of alkyl fragments.
Iridium-catalyzed asymmetric isomerization of primary allylic alcohols
Mantilli, Luca,Gerard, David,Torche, Sonya,Besnard, Celine,Mazet, Clement
supporting information; experimental part, p. 5143 - 5147 (2009/12/07)
Nothing to sm(Ir)k at: Under appropriate reaction conditions, iridium hydride catalysts promote the isomerization of primary allylic alcohols. The best catalysts, like (R)-1 (P green, O red, N blue, Ir yellow), deliver the desired chiral aldehydes with excellent enantioselectivity and good yields. Mechanistic hypotheses have been developed on the basis of preliminary investigations.
A versatile new catalyst for the enantioselective isomerization of allylic alcohols to aldehydes: Scope and mechanistic studies
Tanaka, Ken,Fu, Gregory C.
, p. 8177 - 8186 (2007/10/03)
A new planar-chiral bidentate phosphaferrocene ligand (2) has been synthesized and structurally characterized. The derived rhodium complex, [Rh(cod)(2)]BF4, serves as an effective catalyst for asymmetric isomerizations of allylic alcohols to aldehydes, furnishing improved yields, scope, and enantioselectivities relative to previously reported methods. The catalyst is air-stable and can be recovered at the end of the reaction. Mechanistic studies establish that the isomerization proceeds via an intramolecular 1,3-hydrogen migration and that the catalyst differentiates between the enantiotopic C1 hydrogens.
Asymmetric Michael Additions to α,β-Unsaturated Oxazolines. An Efficient Preparation of Chiral β,β-Disubstituted Propionaldehydes
Meyers, A. I.,Shipman, Michael
, p. 7098 - 7102 (2007/10/02)
A short stereoselective route to a variety of chiral, nonracemic α,β-unsaturated oxazolines derived from (S)-tert-leucinol is described.Addition of organolithium reagents to this chiral oxazoline occurs in a Michael fashion, giving rise to adducts with hi
