- Cu-Catalyzed Hydroxymethylation of Unactivated Alkyl Iodides with CO To Provide One-Carbon-Extended Alcohols
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We have developed a reductive carbonylation method by which unactivated alkyl iodides can be hydroxymethylated to provide one-carbon-extended alcohol products under Cu-catalyzed conditions. The method is tolerant of alkyl β-hydrogen atoms, is robust towards a wide variety of functional groups, and was applied to primary, secondary, and tertiary alkyl iodide substrates. Mechanistic experiments indicate that the transformation proceeds by atom-transfer carbonylation (ATC) of the alkyl iodide followed in tandem by two CuH-mediated reductions in rapid succession. This radical mechanism renders the Cu-catalyzed system complementary to precious-metal-catalyzed reductive carbonylation reactions.
- Zhao, Siling,Mankad, Neal P.
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supporting information
p. 5867 - 5870
(2018/04/17)
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- NRF2 REGULATORS
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Provided are aryl analogs,pharmaceutical compositions containing them and their use as NRF2 regulators.
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Page/Page column 368
(2017/01/02)
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- Exceptionally high decarboxylation rate of a primary aliphatic acyloxy radical determined by radical product yield analysis and quantitative 1H-CIDNP spectroscopy
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Symmetrical (RCO2CO2R; R=XCH2CH 2) and asymmetrical (RCO2CO2R′; R=C 9H19CH2CH2, R′=CH3 or m-ClC6H4) primary diacyl peroxides were thermally decomposed under different conditions to analyze the decarboxylation rates of the thermally generated acyloxy radicals. Quantitative models of the geminate product yields, and qualitative and quantitative 1H-CIDNP spectroscopy were used to obtain the decarboxylation rate estimates. Results reported here suggest that, unlike short chain acyloxy radicals such as propanoyloxyl, long chain acyloxy radicals possess the highest decarboxylation rates of all known acyloxy radicals, estimated at (0.5-1.5)× 10 12s-1 between 80 and 140°C. Given the nature of the dissociative state of acyloxy radicals, such rates appear to be the result of destabilization of the former by the steric bulk of the long chain substituents. Additionally, the rate of this order of magnitude suggests a nearly concerted decarboxylation of primary diacyl peroxides. Copyright
- Fraind, Alicia,Turncliff, Ryan,Fox, Teri,Sodano, Justin,Ryzhkov, Lev R.
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scheme or table
p. 809 - 820
(2012/06/29)
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- AZAINDOLE GLUCOKINASE ACTIVATORS
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Provided herein are compounds of the formula (I): as well as pharmaceutically acceptable salts thereof, wherein the substituents are as those disclosed in the specification. These compounds, and the pharmaceutical compositions containing them, are useful for the treatment of metabolic diseases and disorders such as, for example, type II diabetes mellitus.
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Page/Page column 13
(2011/06/26)
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- Improved method for the diimide reduction of multiple bonds on solid-supported substrates
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(Chemical Equation Presented) A mild and improved method for reducing multiple bonds on various resins with diimide is described. The simple procedure readily generates diimide from 2-nitrobenzenesulfonohydrazide and triethylamine at room temperature. A number of representative multiple bonds in various steric and electronic environments were examined, including polar double bonds such as carbonyl and azo, for ease and selectivity of reduction. A general trend of reactivity was identified which revealed, inter alia, that terminal olefins, 1,2-disubstituted olefins, electron-poor olefins, and terminal alkynes were the most easily reduced.
- Buszek, Keith R.,Brown, Neil
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p. 3125 - 3128
(2008/02/07)
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- Mechanistic studies of olefin metathesis by ruthenium carbene complexes using electrospray ionization tandem mass spectrometry
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The olefin metathesis reaction of the Grubbs ruthenium carbene complexes has been investigated in the gas phase by electrospray ionization tandem mass spectrometry. Relative rates of reaction for substituted ruthenium benzylidenes and alkylidenes after removal of one phosphine ligand were interpreted with the aid of linear free energy analysis and kinetic isotope effects. The experimental observations are consistent with a reaction profile in which the metallacyclobutane structure is a transition state rather than an intermediate, although alternative explanations cannot be wholly ruled out. Electron withdrawal on the carbene moiety is found to accelerate the metathesis reaction when only the metathesis step itself is examined. Quantum chemical calculations at a variety of levels were performed to check for the consistency of the interpretation.
- Adlhart, Christian,Hinderling, Christian,Baumann, Harold,Chen, Peter
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p. 8204 - 8214
(2007/10/03)
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- Synthesis and antiallergy activity of [1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyrimidin-9(3H)-one derivatives. II. 6-Alkyl- and 6-cycloalkylalkyl derivatives
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A series of 6-alkyl- or 6-(cycloalkylalkyl)-[1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]pyr imidin-9(3H)-ones 1b-o was synthesized from the corresponding 1,3,4-thiadiazol-5-amines 3b-o and the antiallergic activities of the products were evaluated. Among the compounds 6-(2-cyclohexylethyl)-[1,3,4]thiadiazolo[3,2-a]-1,2,3-triazolo[4,5-d]p yrimidin-9(3H)-one 1h, whose X-ray crystallographic stereostructure is shown, was found to be a promising new antiallergic agent, which has low toxicity and dual activity as a leukotriene D4 receptor antagonist and as an orally active mast cell stabilizer.
- Yokohama,Miwa,Aibara,Fujiwara,Matsumoto,Nakayama,Iwamoto,Mori,Moroi,Tsukada,Isoda
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p. 2391 - 2398
(2007/10/02)
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- Synthesis of Oxa- and Thia- analogs of Bicycloalkanes
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A general and convenient synthetic approach of a variety of oxa- and thia- analogs of bicycloalkanes is described.This is illustrated by the synthesis of a series of 2-oxa(IIa-d)- and 2-thia(IIa-d)- analogs of bicyclooctane(I) on one hand and 4-oxa(Va-d)- and 4-thia(VIa-d)- analogs of bicyclodecane(IV) on the other.The analogs of I and IV are obtained by cyclohydration of the diols XIX and XXI respectively usung dil.H2SO4 or DMSO.The diols in turn are prepared starting from the keto acids VII.On the otherhand, treatment of di-tosylates XX and XXII of XIX and XXI with Na2S in refluxing ethanol affords the respective 2-thia(III)- and 4-thia(VI)- analogs of I and IV systems.The formation of oxolans(II) via oxidative cyclisation of the cycloalkaneethanols(XXIII) with lead tetraacetate is also described.
- Rao, R. R.,Sarkar, Rina,Bhattacharya, Sukla,Mukherjee, M. N.
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p. 939 - 946
(2007/10/02)
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- SYNTHESIS OF dl-PENTALENOLACTONES E AND F.
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The methyl esters of ( plus or minus )-pentalenolactone E and F have been synthesized by a route based on the intramolecular insertion of an alpha -acylcarbene into an unactivated C-H bond to effect closure of the key fused delta -lactone ring system. Lactone reduction, deketalization, and selective acetalization of the derived lactol provided as a mixture of epimers.
- Cane,Thomas
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p. 5295 - 5303
(2007/10/12)
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