309270-99-3Relevant articles and documents
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.
Rh-Catalyzed Asymmetric Hydrogenation of β-Branched Enol Esters for the Synthesis of β-Chiral Primary Alcohols
Liu, Chong,Yuan, Jing,Zhang, Jian,Wang, Zhihui,Zhang, Zhenfeng,Zhang, Wanbin
, p. 108 - 111 (2018/01/17)
An asymmetric hydrogenation of β-branched enol esters has been developed for the first time, providing a new route for the synthesis of β-chiral primary alcohols. Using a (S)-SKP-Rh complex bearing a large bite angle and enol ester substrates possessing an O-fomyl directing group, the desired products were obtained in quantitative yields and with excellent enantioselectivities.
Ruthenium-catalyzed oxidation of allyl alcohols with intermolecular hydrogen transfer: Synthesis of α,β-unsaturated carbonyl compounds
Ren, Kai,Hu, Bei,Zhao, Mengmeng,Tu, Yahui,Xie, Xiaomin,Zhang, Zhaoguo
, p. 2170 - 2177 (2014/04/03)
Ruthenium-catalyzed oxidation of multisubstituted allyl alcohols in the presence of benzaldehyde gives enals or enones in good yields. Unlike the commonly reported ruthenium-catalyzed isomerization reaction of allyl alcohols to give saturated ketones, an intermolecular rather than intramolecular hydrogen transfer is involved in this transformation. This reaction offers an efficient, mild, and high-yielding method for the preparation of substituted α,β-unsaturated compounds.
Highly enantioselective asymmetric isomerization of primary allylic alcohols with an iridium-N,P complex
Li, Jia-Qi,Peters, Byron,Andersson, Pher G.
supporting information; experimental part, p. 11143 - 11145 (2011/10/31)
Access to chiral aldehydes: The asymmetric isomerization of primary allylic alcohols was studied with a bicyclic phosphine-oxazoline iridium catalyst. This method displays a broad substrate scope and leads to the desired chiral aldehydes with excellent enantioselectivities (see scheme; R1, R 2=Ar or alkyl). Copyright
Improved catalysts for the iridium-catalyzed asymmetric isomerization of primary allylic alcohols based on charton analysis
Mantilli, Luca,Gerard, David,Torche, Sonya,Besnard, Celine,Mazet, Clement
supporting information; experimental part, p. 12736 - 12745 (2011/02/21)
An improved generation of chiral cationic iridium catalysts for the asymmetric isomerization of primary allylic alcohols is disclosed. The design of these air-stable complexes relied on the preliminary mechanistic information available, and on Charton analyses using two preceding generations of iridium catalysts developed for this highly challenging transformation. Sterically unbiased chiral aldehydes that were not accessible previously have been obtained with high levels of enantioselectivity, thus validating the initial hypothesis regarding the selected ligand-design elements. A rationale for the high enantioselectivities achieved in most cases is also presented. Achieving enantioselectivity: An improved generation of chiral cationic iridium catalysts for the asymmetric isomerization of primary allylic alcohols is disclosed. The design of these air-stable complexes relies on preliminary mechanistic information and on Charton analyses using two preceding generations of iridium catalysts developed for this highly challenging transformation (see figure).
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.
Synthesis of isoaminile mediated by enzymes
Antonietti, Fabrizio,Brenna, Elisabetta,Fuganti, Claudio,Gatti, Francesco G.,Giovenzana, Tommaso,Grande, Valentina,Malpezzi, Luciana
, p. 1148 - 1156 (2007/10/03)
A lipase-mediated synthesis of all four enantiomers of isoaminile is reported. The key issues of the paper are: (i) enantioselective acetylation of allylic alcohol (E)-(±)-5 to give (E,S)-5 (ee = 92%) and (E,R)-6 (ee > 99%); (ii) Claisen-Johnson rearrange
On the regioselectivity of Pd-catalyzed additions of organoboronic acids to unsymmetrical alkynes
Kim, Nakjoon,Kim, Ki Seong,Gupta, Aruna Kumar,Oh, Chang Ho
, p. 618 - 619 (2007/10/03)
The Pd-catalyzed reaction of unsymmetrical alkynes 1 with organoboronic acids 2 gave a mixture of products 3 and 4, whose ratios were controlled by the electronic as well as steric effects of the substrates 1.
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.
