- Divergent Synthetic Route to Oxidized Benzofulvene Sesquiterpenoids: Protecting-Group-Free Total Synthesis of Nicotianasesterpenes A, B, and a Polygonum Sesquiterpenoid
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A divergent approach toward the protecting-group-free total synthesis of oxidized benzofulvene sesquiterpenoids is described. Highlight of our synthesis includes regio- and stereoselective assembly of the common intermediate 9 by the orchestrated application of a Pd(0)-catalyzed reductive dehalogenation, a solvent-free methylenation, and a vinylogous Stork enamine aldol condensation in a substrate-controlled manner. The advanced intermediate 9 was efficiently transformed to nicotianasesterpenes A, B, and a polygonum sesquiterpenoid, respectively.
- Jeong, Myeonggyo,Lee, Hyunkee,Kim, Gibeom,Jo, Jeyun,Chang, Jae Won,Jung, Jee H.,Suh, Young-Ger,Yun, Hwayoung
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p. 6714 - 6719
(2019/11/02)
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- Non-conventional methodologies in the synthesis of 1-indanones
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1-Indanones have been successfully prepared by means of three different non-conventional techniques, namely microwaves, high-intensity ultrasound and a Q-tube reactor. A library of differently substituted 1-indanones has been prepared via one-pot intramolecular Friedel-Crafts acylation and their efficiency and "greenness" have been compared.
- Oliverio, Manuela,Nardi, Monica,Costanzo, Paola,Cariati, Luca,Cravotto, Giancarlo,Giofre, Salvatore Vincenzo,Procopio, Antonio
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p. 5599 - 5610
(2014/06/10)
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- Efficient synthesis and resolution of novel 2-(hydroxymethyl)-7,8-dihydro- 1H-indeno[5,4-b] furan-6(2H)-one by lipase Pseudomonas cepacia
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Lipase Pseudomonas cepacia catalyzed acylation of (±)-2- (hydroxymethyl)-7,8-dihydro-1H-indeno[5,4-b] furan-6(2H)-one using vinyl acetate as the acyl donor in acetone gave (-)-(R)-2-acetoxy-2-(methyl)-7,8-dihydro-1H- indeno[5,4-b] furan-6(2H)-one and (+)-(S)-2-(hydroxymethyl)-7,8-dihydro-1H- indeno[5,4-b] furan-6(2H)-one with high enantiomeric excess. Enantiomerically pure 2-(hydroxymethyl)-7,8-dihydro-1H-indeno[5,4-b] furan-6(2H)-one are useful intermediates for the preparation of Ramelteon, an FDA approved drug for the treatment of insomnia.
- Nagarapu, Lingaiah,Vulupala, Hanmanth Reddy,Bantu, Rajashaker,Sajja, Yashodakrishna,Nanubolu, Jagadeesh Babu
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p. 578 - 582
(2014/05/06)
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- Synthesis and evaluation of dimeric 1,2,3,4-Tetrahydro-naphthalenylamine and Indan-1-ylamine derivatives with mast cell-stabilising and anti-allergic activity
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In a continuation of our studies into 4-Amino-3,4-dihydro-2H-naphthalen-1-ones as novel modulators of allergic and inflammatory phenomena, we have extended our work to include dimeric analogues. Of these derivatives, the most promising activity was seen with tertiary amine 58a, which exhibited potent mast cell-stabilising activity in vitro against a variety of stimuli and also in vivo against passive cutaneous anaphylaxis.
- Barlow, James W.,Walsh, John J.
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scheme or table
p. 25 - 37
(2010/03/04)
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- Meldrum's acids as acylating agents in the catalytic intramolecular Friedel-Crafts reaction
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(Chemical Equation Presented) The intramolecular Friedel-Crafts acylation of aromatics with Meldrum's acid derivatives catalyzed by metal trifluoromethanesulfonates is reported. Meldrum's acids are easily prepared, functionalized, handled, and purified. The synthesis of polysubstituted 1-indanones from benzyl Meldrum's acids was investigated thoroughly, and it was shown that a variety of catalysts were effective, while accommodating a diversity of functional groups under mild conditions. The scope, limitations, and functional group tolerance (terminal alkene and alkyne, ketal, dialkyl ether, dialkyl thioether, aryl methyl ether, aryl TIPS and TBDPS ethers, nitrile- and nitro-substituted aryls, alkyl and aryl halides) for a variety of 5-benzyl (enolizable Meldrum's acids) and 5-benzyl-5-substituted Meldrum's acids (quaternized Meldrum's acids), forming 1-indanones and 2-substituted-1- indanones, respectively, are delineated. This method was further applied to the synthesis of 1-tetralones, 1-benzosuberones, and the potent acetylcholinesterase inhibitor donepezil. Rate of cyclization as a function of ring size was established for various benzocyclic ketones via competition experiments: 1-tetralones form faster than both 1-indanones and 1-benzosuberones, and 1-benzosuberones cyclize faster than 1-indanones.
- Fillion, Eric,Fishlock, Dan,Wilsily, Ashraf,Goll, Julie M.
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p. 1316 - 1327
(2007/10/03)
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- Synthesis of 1-indanones by intramolecular Friedel-Crafts reaction of 3-arylpropionic acids catalyzed by Tb(OTf)3
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Intramolecular Friedel-Crafts acylation reaction of 3-arylpropionic acids was efficiently catalyzed by Tb(OTf)3 at 250°C to give 1-indanones. Even deactivated 3-arylpropionic acids with halogen atoms on the aromatic ring can be cyclized in moderation to good yields.
- Cui, Dong-Mei,Zhang, Chen,Kawamura, Masato,Shimada, Shigeru
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p. 1741 - 1745
(2007/10/03)
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- Convenient Access to Polysubstituted 1-Indanones by Sc(OTf) 3-Catalyzed Intramolecular Friedel-Crafts Acylation of Benzyl Meldrum's Acid Derivatives
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(Matrix presented) The intramolecular Friedel-Crafts acylation of benzyl Meldrum's acids is catalyzed by Sc(OTf)3 under mild reaction conditions. Several polysubstituted 1-indanones have been prepared.
- Fillion, Eric,Fishlock, Dan
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p. 4653 - 4656
(2007/10/03)
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- Rhodium Complex-Catalyzed Desilylative Cyclocarbonylation of 1-Aryl-2-(trimethylsilyl)acetylenes: A New Route to 2,3-Dihydro-1H-inden-1-ones
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Under water gas shift reaction conditions, 1-aryl-2-(trimethylsilyl)acetylenes undergo Rh-catalyzed desilylative cyclocarbonylation to give 2,3-dihydro-1H-inden-1-ones and trimethylsilanol.A wide variety of functional groups, such as methoxy, chloro, acetyl, ethoxycarbonyl, cyano, and trifluoromethyl, are tolerated on the aromatic ring under the reaction conditions.The products were obtained in good to excellent yield whether the substituent on the aromatic ring was electron-donating or electron-withdrawing.The cyclizations of substrates bearing a meta substituent onthe aromatic ring regiospecifically gave 5-substituted-2,3-dihydro-1H-inden-1-ones except when the meta substituent was a methoxy group.The desilylative cyclocarbonylation is an alternative to the conventional preparation of 2,3-dihydro-1H-inden-1-ones, an intramolecular Friedel-Crafts acylation.A possible mechanism for the process is described.
- Takeuchi, Ryo,Yasue, Hiroyuki
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p. 5386 - 5392
(2007/10/02)
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