75834-20-7Relevant articles and documents
Asymmetric hydrogenation of allylic alcohols using ir?N,P-Complexes
Li, Jia-Qi,Liu, Jianguo,Krajangsri, Suppachai,Chumnanvej, Napasawan,Singh, Thishana,Andersson, Pher G.
, p. 8342 - 8349 (2018/05/23)
In this study, a series of γ,γ-disubstituted and β,γ-disubstituted allylic alcohols were prepared and successfully hydrogenated using suitable N,P-based Ir complexes. High yields and excellent enantioselectivities were obtained for most of the substrates studied. This investigation also revealed the effect of the acidity of the N,P?Ir-complexes on the acid-sensitive allylic alcohols. DFT ΔpKa calculations were used to explain the effect of the N,P-ligand on the acidity of the corresponding Ir-complex. The selectivity model of the reaction was used to accurately predict the absolute configuration of the hydrogenated alcohols.
Enantioselective isomerization of primary allylic alcohols into chiral aldehydes with the tol-binap/dbapen/ruthenium(II) catalyst
Arai, Noriyoshi,Sato, Keisuke,Azuma, Keita,Ohkuma, Takeshi
supporting information, p. 7500 - 7504 (2013/07/26)
Efficient isomerization: The title reaction was catalyzed by the [RuCl 2{(S)-tol-binap}{(R)-dbapen}]/KOH system in ethanol at 25°C (see scheme). A series of E- and Z-configured aromatic and aliphatic allylic alcohols, including a simple primary alkyl-substituted compound (E)-3-methyl-2-hepten-1-ol, were transformed into the chiral aldehydes with at least 99 % ee. dbapen=2-dibutylamino-1-phenylethylamine, tol-binap=2,2′- bis(di-4-tolylphosphanyl)-1,1′-binaphthyl. Copyright
Regio- and diastereoselective conjugate addition of Grignard reagents to aryl substituted α,β-unsaturated carbonyl compounds derived from Oppolzer's sultam
Cao, Xiufang,Liu, Fang,Lu, Wenchang,Chen, Gang,Yu, Guang-Ao,Liu, Sheng Hua
, p. 5629 - 5636 (2008/09/21)
Asymmetric conjugate addition of Grignard reagents to aryl substituted α,β-unsaturated carbonyl compounds (1) has been achieved with great regioselectivity (>20:1) and good to excellent diastereoselectivity (de up to 98%). The nucleophilicity and stereospecific blockade of the Grignard reagents play a key role in controlling the regioselectivities and diastereoselectivities of the conjugate addition reaction.
Lipase catalyzed acylation of primary alcohols with remotely located stereogenic centres: the resolution of (±)-4,4-dimethyl-3-phenyl-1-pentanol
Sabbani, Sunil,Hedenstroem, Erik,Andersson, Jimmy
, p. 1712 - 1720 (2008/02/11)
Enantioselective acylation of some (±)-3-alkyl-3-phenyl-1-propanols was performed with enzymes as catalysts. Moderate enantiomeric ratios (E), ranging up to E = 11.6, were obtained. In the resolution, some of the lipases selectively acylated the (+)-enant
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.
Chiral Homoenolate Equivalents, II. - Asymmetric Synthesis of 3-Substituted 3-Phenylpropionaldehydes via Metallated Chiral Cinnamylamines
Ahlbrecht, Hubertus,Enders, Dieter,Santowski, Ludger,Zimmermann, Gerd
, p. 1995 - 2004 (2007/10/02)
The diastereomeric excess obtained in alkylation reactions of the chiral homoenolate equivalent 22 with prolinol ether as chiral auxiliary leading to the formation of phenylpropionaldehydes 24 depends strongly on the solvent used.The structure of the alkylating reagent on the other hand is not important.The best results (about 9:1) are obtained in tert-butyl methyl ether as solvent.Other chiral auxiliaries testet were uneffective. - Key Words: Chiral homoenolate equivalents / Alkylation / Chiral 1-aminoallyl anions / Chiral aldehydes
CHIRAL HOMOENOLATE EQUIVALENTS. I. ASYMMETRIC SYNTHESIS OF β-SUBSTITUTED ALDEHIDES VIA METALATED CHIRAL ALLYLAMINES
Ahlbrecht, Hubertus,Bonnet, Gerhard,Enders, Dieter,Zimmermann, Gerd
, p. 3175 - 3178 (2007/10/02)
Metalated chiral allylamines of type 2 (M = Li, K) are used as chiral homoenolate equivalents and allow after alkylation and acidic hydrolysis asymmetric C-C bond formations to β-substituted aldehydes in enantiomeric excesses up to 67percent.