2845-28-5Relevant academic research and scientific papers
Rhodium-Catalyzed Asymmetric Conjugate Alkynylation of β,γ-Unsaturated α-Ketoesters
Zhi, Yanle,Huang, Jianhang,Liu, Na,Lu, Tao,Dou, Xiaowei
, p. 2378 - 2381 (2017)
The first example of catalytic asymmetric conjugate alkynylation of β,γ-unsaturated α-ketoesters is reported. By using Rh(I)/(R)-DM-binap complex as the catalyst and diphenyl[(triisopropylsilyl)ethynyl]methanol as the alkynylating reagent, the alkynylation reaction proceeded smoothly to afford α-ketoesters bearing a propargylic chiral center at γ position in good yields with high enantioselectivities.
P-Chiral Monophosphorus Ligands for Asymmetric Copper-Catalyzed Allylic Alkylation
Xiong, Wenrui,Xu, Guangqing,Yu, Xinhong,Tang, Wenjun
, p. 4003 - 4013 (2019/06/24)
Asymmetric copper-catalyzed allylic alkylation between allyl bromides and alkyl Grignard reagents using a P-chiral monophosphorus ligand is described. A range of terminal olefins bearing tertiary or quaternary carbon centers were formed in good branched/linear selectivities and excellent enantioselectivities at copper loadings as low as 0.5 mol %.
Alkyl Ethers as Traceless Hydride Donors in Br?nsted Acid Catalyzed Intramolecular Hydrogen Atom Transfer
Gandamana, Dhika Aditya,Wang, Bin,Tejo, Ciputra,Bolte, Benoit,Gagosz, Fabien,Chiba, Shunsuke
, p. 6181 - 6185 (2018/05/03)
A new protocol for the deoxygenation of alcohols and the hydrogenation of alkenes under Br?nsted acid catalysis has been developed. The method is based on the use of either a benzyl or isopropyl ether as a traceless hydrogen-atom donor, and involves an intramolecular hydride transfer as a key step, which is achieved in a regio- and stereoselective manner.
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 halogenative semi-pinacol rearrangement: A stereodivergent reaction on a racemic mixture
Romanov-Michailidis, Fedor,Pupier, Marion,Gune, Laure,Alexakis, Alexandre
, p. 13461 - 13464 (2015/02/19)
An efficient, quantitative deracemization strategy for optically inactive allylic cycloalkanols has been achieved using the biphasic halogenative semi-pinacol reaction protocol. The resultant β-halo spiroketones, containing three contiguous stereogenic ce
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
Synthesis of allylic and homoallylic alcohols from unsaturated cyclic ethers using a mild and selective C-O reduction approach
MacK, Daniel J.,Guo, Boying,Njardarson, Jon T.
scheme or table, p. 7844 - 7846 (2012/09/05)
Unsaturated cyclic ethers can be mildly and selectively reduced with catalytic amounts of B(C6F5)3 in the presence of an alkylsilane. The allylic position is preferentially reduced with minimal or no scrambling of olefin geometry. For electronically equivalent substrates, steric factors guide the reducing agent to the least substituted site.
Chiral γ-aryl-1H-1,2,4-triazole derivatives as highly potential antifungal agents: Design, synthesis, structure, and in vitro fungicidal activities
Cao, Xiufang,Li, Fei,Hu, Ming,Lu, Wenchang,Yu, Guang-Ao,Sheng, Hua Liu
experimental part, p. 11367 - 11375 (2010/03/31)
A novel series of chiral γ-aryl-1H-1,2,4-triazole derivatives as highly potential antifungal agents have been designed and synthesized conveniently by using the chiral auxiliary as a controlling reagent. All of the compounds exhibit moderate to high ee va
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
