55177-35-0Relevant academic research and scientific papers
Organocatalytic Asymmetric Multicomponent Cascade Reaction for the Synthesis of Contiguously Substituted Tetrahydronaphthols
Izzo, Joseph A.,Liu, Yidong,Mcleod, David,Poulsen, Thomas B.,Svenningsen, Esben B.,J?rgensen, Karl Anker,Ri?ko, Sebastijan
supporting information, p. 8208 - 8220 (2021/06/27)
Isobenzopyrylium ions are unique, highly reactive, aromatic intermediates which are largely unexplored in asymmetric catalysis despite their high potential synthetic utility. In this study, an organocatalytic asymmetric multicomponent cascade via dienamine catalysis, involving a cycloaddition, a nucleophilic addition, and a ring-opening reaction, is disclosed. The reaction furnishes chiral tetrahydronaphthols containing four contiguous stereocenters in good to high yield, high diastereoselectivity (up to >20:1), and excellent enantioselectivity (93-98% ee). The obtained products are important synthetic intermediates, and it is demonstrated that they can be used for the generation of frameworks such as octahydrobenzo[h]isoquinoline and [2.2.2]octane scaffolds. Furthermore, mechanistic experiments involving oxygen-18-labeling studies and density functional theory calculations provide a vivid picture of the reaction mechanism. Finally, the bioactivity of 16 representative tetrahydronaphthol compounds has been evaluated in U-2OS cancer cells with some compounds showing a unique profile and a clear morphological change.
Palladium/Copper-catalyzed Oxidation of Aliphatic Terminal Alkenes to Aldehydes Assisted by p-Benzoquinone
Komori, Saki,Yamaguchi, Yoshiko,Murakami, Yuka,Kataoka, Yasutaka,Ura, Yasuyuki
, p. 3946 - 3955 (2020/07/06)
The development of an anti-Markovnikov Wacker-type oxidation for simple aliphatic alkenes is a significant challenge. Herein, a variety of aldehydes can be selectively obtained from various unbiased aliphatic terminal alkenes using PdCl2(MeCN)2/CuCl in the presence of p-benzoquinone (BQ) under mild reaction conditions. Isomerization of the terminal alkene to the internal alkene was suppressed via slow addition of the starting material to the reaction mixture. In addition to the Pd catalyst, CuCl and BQ were essential in order to obtain the anti-Markovnikov product with high selectivity. Terminal alkenes bearing a halogen substituent afforded their corresponding aldehydes with high anti-Markovnikov selectivity. The halogen acts as a directing group in the reaction. DFT calculations indicate that a μ-chloro Pd(II)?Cu(I) bimetallic species with BQ coordinated to Cu is the catalytically active species in the case of a terminal alkene without a directing group.
Repetition of chemistry from a recently retracted paper. A cautionary note
Ryan, Wilson,Bedard, Korey,Baidilov, Daler,Tius, Marcus,Hudlicky, Tomas
supporting information, p. 2467 - 2469 (2018/06/25)
The base-catalyzed condensation reaction between (E)-4-phenylbut-2-enal and phenylpropargyl aldehyde recently reported in the literature to provide formylcyclobutadiene was repeated under the published conditions. The product obtained was identified as (E)-5-phenyl-2-((E)-styryl)pent-2-en-4-ynal rather than the reported 2-phenyl-3-styrylcyclobutadiene-1-carboxaldehyde. The structure assignment is supported by NMR and IR data and a x-ray structure of the crystalline alcohol obtained by Luche reduction.
Practical asymmetric synthesis of Sitagliptin phosphate monohydrate
Gao, Haoling,Yu, Jiangang,Ge, Chengsheng,Jiang, Qun
, (2018/06/29)
Optically pure sitagliptin phosphate monohydrate is efficiently and practically synthesized through a chiral hemiacetal as the key intermediate in 54% overall yield starting from (E)-4-(2,4,5-trifluorophenyl)but-2-enal and N-boc-protected hydroxylamine. The chiral hemiacetal fragment is constructed by a tandem aza-Michael/hemiacetal reaction catalyzed by an organocatalyst and the influence of acidity of Br?nsted acid on tandem aza-Michael/hemiacetal reaction is researched in detail.
Concise synthesis of valuable chiral N-Boc-β-benzyl-β-amino acid via construction of chiral N-Boc-3-benzyl-5-oxoisoxazolidine through cross-metathesis/conjugate addition/oxidation
Jiang, Hong-Tao,Gao, Hao-Ling,Ge, Cheng-Sheng
supporting information, p. 471 - 475 (2017/01/25)
Valuable chiral N-Boc-β-benzyl-β-amino acid was concisely synthesized via construction of chiral N-Boc-3-benzyl-5-oxoisoxazolidine through cross-metathesis/conjugate addition/oxidation. All of the starting materials for the synthesis of chiral N-Boc-β-ben
Synthesis of α-pyrones by catalytic oxidative coupling of terminal alkynes and carbon dioxide
Oliveros-Cruz, Saray,Arévalo, Alma,García, Juventino J.
, p. 18 - 22 (2017/01/10)
The use of the complex [(dippe)Ni(μ-H)]2(1) as a catalyst precursor (10?mol%) in the presence of a variety of terminal alkynes and CO2allowed the production of substituted α–pyrones. This reaction occurs using relatively mild conditions (50?°C, 150 psi of CO2) with good to modest yields, depending on the nature of the substituents in the corresponding alkyne. The produced α–pyrones were characterized by different analytical methods and spectroscopic techniques.
Stereoselective Organocatalytic Synthesis of α,α-Difluoro-γ,γ-Disubstituted Butenals
Arimitsu, Satoru,Nakasone, Makoto
, p. 6707 - 6713 (2016/08/16)
A highly stereoselective reaction of α,α-difluoro-γ,γ-disubstituted butenals 2 bearing two different substituents at the γ position has been developed with an organocatalytic system of l-proline (30 mol %) and salicylic acid (60 mol %). This novel reactio
Organoselenium-catalyzed, hydroxy-controlled regio- and stereoselective amination of terminal alkenes: Efficient synthesis of 3-amino allylic alcohols
Deng, Zhimin,Wei, Jialiang,Liao, Lihao,Huang, Haiyan,Zhao, Xiaodan
supporting information, p. 1834 - 1837 (2015/04/27)
An efficient route to prepare 3-amino allylic alcohols in excellent regio- and stereoselectivity in the presence of bases by orangoselenium catalysis has been developed. In the absence of bases α,β-unsaturated aldehydes were formed in up to 97% yield. Control experiments reveal that the hydroxy group is crucial for the direct amination.
Palladium-catalyzed reactions of enol ethers: Access to enals, furans, and dihydrofurans
Lauer, Matthew G.,Henderson, William H.,Awad, Amneh,Stambuli, James P.
supporting information, p. 6000 - 6003 (2013/02/25)
The palladium-catalyzed oxidation of alkyl enol ethers to enals, which employs low loadings of a palladium catalyst, is described. The mild oxidation conditions tolerate a diverse array of functional groups, while allowing the formation of di-, tri-, and tetrasubtituted olefins. The application of this methodology to intramolecular reactions of alkyl enol ethers containing pendant alcohols provides furan and 2,5-dihydrofuran products.
