72985-23-0Relevant academic research and scientific papers
Squaramide-catalyzed asymmetric intramolecular oxa-michael reaction of α,β-unsaturated carbonyls containing benzyl alcohol: Construction of chiral 1-substituted phthalans
Son, Eun Chae,Kim, Seung Yeon,Kim, Sung-Gon
, p. 6826 - 6839 (2021/05/29)
Organocatalytic enantioselective intramolecular oxa-Michael reactions of benzyl alcohol bearing α,β-unsaturated carbonyls as Michael acceptors are presented herein. Using cinchona squaramide-based organocatalyst, enones as well as α,βunsaturated esters containing benzyl alcohol provided their corresponding 1,3-dihydroisobenzofuranyl-1-methylene ketones and 1,3-dihydroisobenzofuranyl-1-methylene esters in excellent yields with high enantioselectivities. In addition, enantioenriched 1,3-dihydroisobenzofuranyl-1-methylene ketone could be obtained from the Wittig/oxa-Michael reaction cascade of 1,3-dihydro-2-benzofuran-1-ol.
Enantioselective synthesis of 3-aryl-phthalides through a nickel-catalyzed stereoconvergent cross-coupling reaction
Feng, Chen-Guo,Xu, Si-Yu,Zhang, Rui,Zhang, Shu-Sheng
supporting information, p. 4492 - 4496 (2021/05/31)
A nickel-catalyzed asymmetric Suzuki-Miyaura cross-coupling of racemic 3-bromo-phthalides and arylboronic acids was realized for the synthesis of diverse chiral 3-aryl-phthalides in moderate to excellent reaction yields. The reaction proceeded in a stereoconvergent manner and high enantioselectivities were observed for most examined examples. A number of functional groups like aldehyde, ester and bromide were well tolerated. Heteroaromatic boronic acids were also competent coupling partners in this reaction.
Organocatalytic enantioselective synthesis of phthalans via Wittig/oxa-Michael cascade reaction
Son, Eun Chae,No, Jaeeun,Kim, Sung-Gon
, p. 1473 - 1480 (2021/09/25)
An enantioselective synthetic method for 1-substituted phthalans has been developed. The organocatalytic reaction between 1,3-dihydro-2-benzofuran-1-ols and Wittig reagents using cinchona squaramide-based organocatalyst proceeded with sequential Wittig reaction followed by an enantioselective intramolecular oxa-Michael reaction, yielding enantioenriched phthalans with moderate to good enantioselectivities.
Chiral Bicyclic Imidazole-Catalyzed Acylative Dynamic Kinetic Resolution for the Synthesis of Chiral Phthalidyl Esters
Zhou, Muxing,Gridneva, Tatiana,Zhang, Zhenfeng,He, Ende,Liu, Yangang,Zhang, Wanbin
supporting information, p. 1641 - 1645 (2020/11/30)
Utilizing a chiral bicyclic imidazole organocatalyst and adopting a continuous injection process, an alternative route has been developed for the efficient synthesis of chiral phthalidyl ester prodrugs via dynamic kinetic resolution of 3-hydroxyphthalides through enantioselective acylation (up to 99 % ee). The computational studies suggest a general base catalytic mechanism differing from the widely accepted nucleophilic catalytic mechanism. The structure analysis of the key transition states shows that the CH-π interactions and not the previously considered cation/π-π interactions between the catalyst and substrate is the dominant factor giving rise to the observed stereocontrol.
Synthesis of 3-Unsubstituted Phthalides from Aryl Amides and Paraformaldehyde via Ruthenium(II)-Catalyzed C–H Activation
Zhou, Chao,Zhao, Junqi,Chen, Wenkun,Imerhasan, Mukhtar,Wang, Jun
supporting information, p. 6485 - 6488 (2020/10/02)
A straightforward and convenient route has been developed for the synthesis of 3-unsubstituted phthalide derivatives from aryl amides and paraformaldehyde by ruthenium(II)-catalyzed C–H activation. The reaction proceeds through tandem ortho-hydroxymethylation of aryl amide and subsequent intramolecular lactonization.
Ligand-enabled pd(ii)-catalyzed c(sp3)-h lactonization using molecular oxygen as oxidant
Qian, Shaoqun,Li, Zi-Qi,Li, Minyan,Wisniewski, Steven R.,Qiao, Jennifer X.,Richter, Jeremy M.,Ewing, William R.,Eastgate, Martin D.,Chen, Jason S.,Yu, Jin-Quan
supporting information, p. 3960 - 3963 (2020/05/22)
Pd(II)-catalyzed C-H lactonization of o-methyl benzoic acid substrates has been achieved using molecular oxygen as the oxidant. This finding provides a rare example of C-H oxygenation through Pd(II)/Pd(0) catalysis as well as a method to construct biologically important benzolactone scaffolds. The use of a gas mixture of 5% oxygen in nitrogen demonstrated the possibility for its application in pharmaceutical manufacturing.
DIELS-ALDER REACTION WITH FURANICS TO OBTAIN AROMATICS
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Page/Page column 19, (2020/03/23)
The present invention is directed to the preparation of phthalic anhydride compounds and the intermediate phthalide compounds. In particular, the invention is directed to an improved bio-based route from furanic compounds to phthalic anhydride compounds by reacting furfuryl alcohol (i.e. 2-hydroxymethylfuran) or an analogue thereof having a nucleophilic atom on the 2-methyl, with a dienophile comprising an α,β-unsaturated carbonyl comprising an α'-leaving group. The inventions further involved preparation of phthalic anhydride compounds, phthalic acid compounds and reduction products of the intermediate phthalide compounds.
Platinum-on-Carbon-Catalyzed Aqueous Oxidative Lactonization of Diols by Using Molecular Oxygen
Ban, Kazuho,Sajiki, Hironao,Sawama, Yoshinari,Takakura, Ryoya
, p. 1919 - 1923 (2019/09/30)
A lactonization of various diols catalyzed by platinum on carbon (Pt/C) in water under an atmosphere of molecular oxygen was developed. Derivatives of 1,4- 1,5- and 1,6-diols were transformed into the corresponding five-, six-, and seven-membered lactones by the present oxidative lactonization method.
A g-C3N4-based heterogeneous photocatalyst for visible light mediated aerobic benzylic C-H oxygenations
Geng, Pengxin,Tang, Yurong,Pan, Guanglong,Wang, Wentao,Hu, Jinchuan,Cai, Yunfei
supporting information, p. 6116 - 6122 (2019/11/20)
A metal-free heterogeneous photocatalytic system has been developed for highly efficient benzylic C-H oxygenations using oxygen as an oxidant. This visible light mediated oxidation reaction utilizes graphitic carbon nitride (g-C3N4) as a recyclable, nontoxic and low cost photocatalyst. Mild reaction conditions allow for the generation of synthetically and biologically valued isochromannones, phthalides, isoquinolinones, isoindolinones and xanthones from readily accessible alkyl aromatic precursors in good yields. The heterogeneous nature of the g-C3N4 catalytic system enables easy recovery and recycling as well as the use in multiple runs without loss of activity. The synthetic utility of this "green" methodology was further demonstrated by applying in bioactive and drug valued target syntheses.
Electron-Transfer-Induced Intramolecular Heck Carbonylation Reactions Leading to Benzolactones and Benzolactams
Fukuyama, Takahide,Bando, Takanobu,Ryu, Ilhyong
supporting information, p. 3015 - 3021 (2018/06/08)
A metal-catalyst-free intramolecular Heck carbonylation reaction of benzyl alcohols and benzyl amines with carbon monoxide under heating at 250 °C affords the corresponding benzolactones and benzolactams in good to excellent yields. A hybrid radical/ionic chain mechanism, involving electron transfer from radical anions generated by nucleophilic attack of alcohols or amines on intermediate acyl radicals, is proposed.
