- 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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- Intramolecular Oxidative Coupling between Unactivated Aliphatic C-H and Aryl C-H Bonds
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Direct oxidative coupling of different inert C-H bonds is the most straightforward and environmentally benign method to construct C-C bonds. In this paper, we developed a Pd-catalyzed intramolecular oxidative coupling between unactivated aliphatic and aryl C-H bonds. This chemistry showed great potential to build up fused cyclic scaffolds from linear substrates through oxidative couplings. Privileged chromane and tetralin scaffolds were constructed from readily available linear starting materials in the absence of any organohalides and organometallic partners.
- Liao, Yang,Zhou, Yi,Zhang, Zhen,Fan, Junzhen,Liu, Feng,Shi, Zhangjie
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p. 1251 - 1257
(2021/03/03)
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- Rapid Construction of Tetralin, Chromane, and Indane Motifs via Cyclative C-H/C-H Coupling: Four-Step Total Synthesis of (±)-Russujaponol F
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The development of practical C-H/C-H coupling reactions remains a challenging yet appealing synthetic venture because it circumvents the need to prefunctionalize both coupling partners for the generation of C-C bonds. Herein we report a cyclative C(sp3)-H/C(sp2)-H coupling reaction of free aliphatic acids enabled by a cyclopentane-based mono-N-protected β-amino acid ligand. This reaction uses inexpensive sodium percarbonate (Na2CO3·1.5H2O2) as the sole oxidant and generates water as the only byproduct. A range of biologically important scaffolds, including tetralins, chromanes, and indanes, can be easily prepared by this protocol. Finally, the synthetic application of this methodology is demonstrated by the concise total synthesis of (±)-russujaponol F in a four-step sequence starting from readily available phenylacetic acid and pivalic acid through sequential functionalizations of four C-H bonds.
- Zhuang, Zhe,Herron, Alastair N.,Liu, Shuang,Yu, Jin-Quan
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p. 687 - 692
(2021/01/25)
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- Direct β-Selective Hydrocarboxylation of Styrenes with CO2 Enabled by Continuous Flow Photoredox Catalysis
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The direct β-selective hydrocarboxylation of styrenes under atmospheric pressure of CO2 has been developed using photoredox catalysis in continuous flow. The scope of this methodology was demonstrated with a range of functionalized terminal styrenes, as well as α-substituted and β-substituted styrenes.
- Seo, Hyowon,Liu, Aofei,Jamison, Timothy F.
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supporting information
p. 13969 - 13972
(2017/10/17)
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- 5-AMINO-4-CARBAMOYL-PYRAZOLE COMPOUNDS AS SELECTIVE AND IRREVERSIBLE T790M OVER WT-EGFR KINASE INHIBITORS AND USE THEREOF????
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Disclosed are compounds of Formula (I), pharmaceutical compositions comprising the same, processes for the preparation thereof, and the use thereof.
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Paragraph 0178
(2016/03/13)
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- Evidence for aromatic ring reduction in the biodegradation pathway of carboxylated naphthalene by a sulfate reducing consortium
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Naphthalene was used as a model compound in order to study the anaerobic pathway of polycyclic aromatic hydrocarbon degradation. Previously we had determined that carboxylation is an initial step for anaerobic metabolism of naphthalene, but no other intermediate metabolites were identified (Zhang & Young 1997). In the present study we further elucidate the pathway with the identification of six novel naphthalene metabolites detected when cultures were fed naphthalene in the presence of its analog 1-fluoronaphthalene. Results from cultures supplemented with either deuterated naphthalene or non-deuterated naphthalene plus [13C]bicarbonate confirm that the metabolites originated from naphthalene. Three of these metabolites were identified by comparison with the following standards: 2-naphthoic acid (2-NA), 5,6,7,8-tetrahydro-2-naphthoic acid, and decahydro-2-naphthoic acid. The presence of 5,6,7,8-tetrahydro-2-NA as a metabolite of naphthalene degradation indicates that the first reduction reaction occurs at the unsubstituted ring, rather than the carboxylated ring. The overall results suggest that after the initial carboxylation of naphthalene, 2-NA is sequentially reduced to decahydro-2-naphthoic acid through 5 hydrogenation reactions, each of which eliminated one double bond. Incorporation of deuterium atoms from D20 into 5,6,7,8-tetrahydro-2-naphthoic acid suggests that water is the proton source for hydrogenation.
- Zhang, Xiaoming,Sullivan, Elise R.,Young
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p. 117 - 124
(2007/10/03)
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- N-acyl sulfamic acid esters (or thioesters), N-acyl sulfonamides, and N-sulfonyl carbamic acid esters (or thioesters) as hypercholesterolemic agents
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The present invention is directed to compounds useful for the regulation of cholesterol of Formula I, methods for using them and pharmaceutical compositions thereof, STR1 wherein X and Y are oxygen, sulfur, or (CR'R")n wherein n is 1 to 4; R is hydrogen, alkyl, or benzyl; R1 and R2 are phenyl, substituted phenyl, naphthyl, substituted naphthyl, an aralkyl group, an alkyl chain, adamantyl, or a cycloalkyl group.
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- STUDIES IN METAL-AMMONIA REDUCTION-5 REDUCTION AND REDUCTIVE METHYLATION OF SOME NAPHTHOIC ACIDS
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Birch reduction and reductive methylation of some substituted naphthoic acids have been examined.The factors influencing the mechanism of reduction process have been discussed.Some of the reduced naphthoic acids are useful synthons for synthesis.
- Murthy, A. Radhakrishna,Sundar, N. Shyama,Rao, G. S. R. Subba
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p. 2831 - 2836
(2007/10/02)
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- Radical Pathways of Coal Dissolution in Hydrogen Donor Media. 2. β Scission and 1,2 Aryl Migration Reactions of Radicals Derived from Methylindans and Tetralin at 327-627 deg C
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The 1,2-aryl migration and fragmentation reactions of 1-indanylmethyl (1), 2-tetralyl (2), 2-indanylmethyl (3), 1-tetralyl (4), 2-methyl-1-indanyl (5), and 1-methyl-2-indanyl (6) radicals were studied by flash vacuum pyrolysis of the tert-butyl perester precursors at 327-627 deg C and 10-2 torr.Radicals 1 and 2 are interconverted via 1,2 aryl migration which is readily reversible at all temperatures.This equilibrium is depleted by β scission of 1 and recyclization to 4 and by β scission of 2 followed by recyclization to 2 or 3 in modest yields.The reverse neophyle-like rearrangement of 2 to 1 occurs with a lower activation barrier than β-scission of 1 to form a 2-(o-vinylphenyl)ethyl radical.Enthalpies, entropies, and free energies of reactions were calculated for the above reactions from group additivity parameters, and activation energies were estimated from values reported for simple alkyl radicals.It is shown that the β scission of 4 and recyclization to 1 is important only at very high temperatures (>500 deg C) as a mechanism for the isomerization of tetralin and related hydroaromatic structures to alkylindans and that the reverse neophyl-like rearrangement of 2 to 1 is the favored pathway for isomerizations observed during dissolution of coal in hydroaromatic media at elevated temperatures.
- Franz, James A.,Camaioni, Donald M.
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p. 5247 - 5255
(2007/10/02)
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