- Catalytic, Cascade Ring-Opening Benzannulations of 2,3-Dihydrofuran O,O- and N,O-Acetals
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An Al(OTf)3-catalyzed intramolecular cascade ring-opening benzannulation of 2,3-dihydrofuran O,O- and N,O-acetals is described. The cascade sequence involves the dihydrofuran ring-opening by acetal hydrolysis, an intramolecular Prins-type cyclization, and aromatization to generate an array of benzo-fused (hetero)aromatic systems in up to 95 % yield. This method represents the first example of dihydrofuran acetal usage in benzannulation reactions. The approach provides excellent regiocontrol based on the choice of alkenes used to form the requisite dihydrofuran acetals.
- Aponte-Guzmán, Joel,Phun, Lien H.,Cavitt, Marchello A.,Taylor, J. Evans,Davy, Jack C.,France, Stefan
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supporting information
p. 10405 - 10409
(2016/07/21)
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- Copper-mediated oxidative transformation of N-allyl enamine carboxylates toward synthesis of azaheterocycles
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A method for synthesis of 3-azabicyclo[3.1.0]hex-2-enes has been developed by intramolecular cyclopropanation of readily available N-allyl enamine carboxylates. Two complementary reaction conditions, CuBr-mediated aerobic and CuBr2-catalyzed-PhIO2-mediated systems effectively induced stepwise cyclopropanation via carbocupration of alkenes. Oxidative cyclopropane ring-opening of 5-substituted 3-azabicyclo[3.1.0]hex-2-enes was also developed for synthesis of highly substituted pyridines. In addition, diastereoselective reduction of 3-azabicyclo[3.1.0]hex-2-enes to 3-azabicyclo[3.1.0]hexanes was achieved using NaBH3CN in the presence of acetic acid.
- Toh, Kah Kah,Biswas, Anup,Wang, Yi-Feng,Tan, Yun Yun,Chiba, Shunsuke
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p. 6011 - 6020
(2014/05/20)
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- HETEROCYCLIC COMPOUNDS FOR THE INHIBITION OF PASK
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Disclosed herein are new heterocyclic compounds and compositions and their application as pharmaceuticals for the treatment of disease. Methods of inhibiting PAS Kinase (PASK) activity in a human or animal subject are also provided for the treatment of diseases such as diabetes mellitus.
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Page/Page column 25
(2012/11/08)
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- Copper-mediated aerobic synthesis of 3-azabicyclo[3.1.0]hex-2-enes and 4-carbonylpyrroles from N-allyl/propargyl enamine carboxylates
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Synthetic methods for 3-azabicyclo[3.1.0]hex-2-enes and 4-carbonylpyrroles have been developed that use copper-mediated/catalyzed reactions of N-allyl/propargyl enamine carboxylates under an O2 atmosphere and involve intramolecular cyclopropanation and carbooxygenation, respectively. These methodologies take advantage of orthogonal modes of chemical reactivity of readily available N-allyl/propargyl enamine carboxylates; the complementary pathways can be accessed by slight modification of the reaction conditions.
- Toh, Kah Kah,Wang, Yi-Feng,Ng, Eileen Pei Jian,Chiba, Shunsuke
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supporting information; body text
p. 13942 - 13945
(2011/10/30)
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- Compounds for treatment of cardiac arrhythmia synthesis, and methods of use
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The subject invention pertains to novel compounds, and compositions comprising the compounds, for the treatment of cardiac arrhythmias. The subject invention further concerns a method of making the novel compounds. The novel compounds are rapidly metabolized analogs of amiodarone, having the distinct and advantageous characteristic of being metabolized to a less lipophilic compound. The new compounds can have particular utility for treating life-threatening ventricular tachyarrhythmias, especially in patients with congestive heart failure (CHF). The product can also provide effective management for ventricular arrhythmias and supraventricular arrhythmias, including atrial fibrillation and re-entrant tachyarrhythmias involving accessory pathways.
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- Synthesis of 4-(2-Benzofuranyl)coumarins
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4-(2-Benzofuranyl)coumarins (3) have been synthesized by two routes, one involving Pechmann condensation of benzofuranpropionic acid-β-oxo-ethyl ester with phenols and the other involving Wittig reaction on 2-(2-hydroxybenzoyl)benzofuran using Ph3P=CHCOOE
- Deshpande, A. R.,Joshi, U. K.,Paradkar, M. V.
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p. 524 - 526
(2007/10/02)
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- KETOCOUMARINS. A NEW CLASS OF TRIPLET SENSITIZERS
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Several derivatives of 3-ketocoumarins were prepared and are shown to have many of the photophysical criteria required for efficient triplet sensitizers.These compounds include 3-aroylcoumarins (1) and 3,3'-carbonyl-biscoumarins (2).The aryl groups in 1 are either phenyl and substituted phenyl derivatives or heterocyclic groups such as thienyl and benzofuryl.The substituents on the coumarin moiety in 1 and 2, if any, are alkoxy or dialkylamino.These compounds, with absorption maxima between 330 and 450 nm, have extinction coefficients in the range of 1E4 to almost 1E5, which is an important criterion for efficient sensitization of thin films of polymers as those used in photoresists and litography.The singlet-triplet intersystem crossing (isc) efficiencies of several derivatives approach unity.In others, however, a radiationless decay process competes with the isc.The decay process is particularly dominant in the assymetrically substituted derivatives of 2, but seems to be considerably supressed in polymeric matrices.The triplet energies of these compounds range from ca. 48 to 60 kcal/mol.Some of these ketocoumarins show phosphorescence spectra that suggest the presence of "frozen-in" rotamers.
- Specht, Donald P.,Martic, Peter A.,Farid, Samir,++
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p. 1203 - 1211
(2007/10/02)
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