- Photoredox Activation of Formate Salts: Hydrocarboxylation of Alkenes via Carboxyl Group Transfer
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A photoredox activation mode of formate salts for carboxylation was developed. Using a formate salt as the reductant, carbonyl source, and hydrogen atom transfer reagent, a wide range of alkenes can be converted into acid products via a carboxyl group tra
- Huang, Yan,Hou, Jing,Zhan, Le-Wu,Zhang, Qian,Tang, Wan-Ying,Li, Bin-Dong
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p. 15004 - 15012
(2021/12/14)
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- Ruthenium-catalyzed intramolecular arene C(sp2)-H amidation for synthesis of 3,4-dihydroquinolin-2(1 H)-ones
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We report the [Ru(p-cymene)(l-proline)Cl] ([Ru1])-catalyzed cyclization of 1,4,2-dioxazol-5-ones to form dihydroquinoline-2-ones in excellent yields with excellent regioselectivity via a formal intramolecular arene C(sp2)-H amidation. The reactions of the 2- and 4-substituted aryl dioxazolones proceeds initially through spirolactamization via electrophilic amidation at the arene site, which is para or ortho to the substituent. A Hammett correlation study showed that the spirolactamization is likely to occur by electrophilic nitrenoid attack at the arene, which is characterized by a negative ρ value of -0.73.
- Au, Chi-Ming,Ling, Cho-Hon,Sun, Wenlong,Yu, Wing-Yiu
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supporting information
p. 3310 - 3314
(2021/05/29)
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- Diastereoselective Pd(II)-Catalyzed sp3 C-H Arylation Followed by Ring Opening of Cyclopropanecarboxamides: Construction of anti β-Acyloxy Carboxamide Derivatives
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The diastereoselective Pd(OAc)2-catalyzed, bidentate ligand-directed sp3 C-H activation/arylation followed by ring opening of cyclopropanecarboxamides, which were assembled from cyclopropanecarbonyl chlorides and bidentate ligands (e.g., 8-aminoquinoline and 2-(methylthio)aniline), has been investigated. The treatment of various cyclopropanecarboxamides with excess amounts of aryl iodides in the presence of the Pd(OAc)2 catalyst, AgOAc and AcOH directly afforded the corresponding multiple β-C-H arylated open-chain carboxamides (anti β-acyloxy amides). This method has led to the construction of several anti β-acyloxy amides that possess vicinal stereocenters with a high degree of stereocontrol with the formation of a new C-O bond and three new C-C bonds. A plausible mechanism for the formation of multiple β-C-H arylated open-chain carboxamides from the Pd-catalyzed, bidentate ligand-directed β-C-H arylation and the ring opening of cyclopropanecarboxamides is proposed based on several control experiments. The observed diastereoselectivity and anti stereochemistry of the β-acyloxy amides were ascertained based on X-ray structural analysis of representative β-acyloxy amides.
- Gopalakrishnan, Bojan,Mohan, Sruthi,Parella, Ramarao,Babu, Srinivasarao Arulananda
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p. 8988 - 9005
(2016/10/17)
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- A Weinreb Amide Based Building Block for Convenient Access to β,β-Diarylacroleins: Synthesis of 3-Arylindanones
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Towards the synthesis of symmetrical and unsymmetrical β,β-diarylacroleins for assembling diarylmethine fragments present in biologically important molecules, we have developed a new Weinreb amide (WA) based building block, derived from propiolic acid. The WA functionality present in this compound allowed the sequential addition of various arylmagnesium bromide reagents in a controlled manner. The developed methodology for the access to β,β-diarylacroleins has been utilised for the synthesis of biologically important 3-arylindanone molecules. Synthesis of both symmetrical and unsymmetrical β,β-diarylacrolein and diarylmethine fragments, have been achieved via easily accessible and hitherto unknown Weinreb Amide (WA) based building block 11. The WA functionality allowed the sequential addition of nucleophiles such as arylmagnesium bromide in a controlled manner, which has enabled the synthesis of an important 3-arylindanone molecule.
- Tiwari, Praveen Kumar,Aidhen, Indrapal Singh
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p. 2637 - 2646
(2016/06/08)
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- A high hydroarylation activity of K2PtCl4/AgOTf catalyst in the reaction of propiolic acid with unactivated and activated arenes
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A mixed catalyst K2PtCl4/AgOTf showed the highest activity for hydroarylation of propiolic acid, among palladium and platinum catalysts. This catalyst was effective for hydroarylation with less reactive benzene to give cis-cinnamic acid in good yield. The hydroarylation with toluene gave a higher yield of hydroarylation products than that with benzene and resulted in ortho/para orientation with an almost statistical ratio, suggesting that the result is very close to that of the Friedel-Crafts alkylation with methyl bromide or p-nitrobenzyl chloride. Hydroarylation of propiolic acid with other electron-rich arenes proceeded efficiently in the presence of the K2PtCl4/AgOTf catalyst in trifluoroacetic acid forming cis-cinnamic acids in good to high yields. This method was also applied to hydroarylation of ethyl propiolate.
- Oyamada, Juzo,Hashimoto, Takuya,Kitamura, Tsugio
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experimental part
p. 3626 - 3632
(2010/01/18)
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- Antiatherosclerotic diphenyl alkanamides
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This disclosure describes novel diaryl-alkanamides. These compounds are useful as pharmaceutical agents for ameliorating atherosclerosis by inhibiting the formation and development of atherosclerotic lesions in the arterial wall of mammals.
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- Aralkanamidophenyl compounds
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This disclosure describes novel substituted aralkanamidobenzoic acids and analogs thereof. These compounds are useful pharmaceutical agents for ameliorating atherosclerosis by inhibiting the formation and development of atherosclerotic lesions in the arterial wall of mammals.
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