869578-02-9Relevant academic research and scientific papers
Synthesis of unsymmetrically disubstituted ethynes by the palladium/copper(I)-cocatalyzed sila-Sonogashira-Hagihara coupling reactions of alkynylsilanes with aryl iodides, bromides, and chlorides through a direct activation of a carbon-silicon bond
Nishihara, Yasushi,Inoue, Eiji,Noyori, Shintaro,Ogawa, Daisuke,Okada, Yoshiaki,Iwasaki, Masayuki,Takagi, Kentaro
experimental part, p. 4869 - 4881 (2012/08/08)
In this paper, we explore the copper/palladium-cocatalyzed cross-coupling reactions of 1-aryl-2-trimethylsilylethynes with aryl iodides, bromides, and chlorides as coupling partners, to furnish unsymmetrically disubstituted ethynes in moderate to excellent yields. Various aryl iodides were subjected to reaction under the optimized conditions with 5 mol % of Pd(PPh3) 2 and 50 mol % of CuCl. The steric properties of the aryl iodide proved more influential to the outcome of the cross-coupling reaction than electronic factors. In addition, we succeeded in synthesizing unsymmetrical diarylethynes using two different aryl iodides in one-pot. Furthermore, under the same reaction conditions with 10 mol % of PdCl2, 40 mol % of P(4-FC6H4)3, and 50 mol % of CuCl as catalyst, we succeeded in synthesizing unsymmetrical diarylethynes from various aryl bromides. Finally, we explored reactions with aryl chlorides and duly discovered that unsymmetrical diarylethynes were obtainable in moderate to good yields when 10 mol % of Pd(OAc)2, 10 mol % of (-)-DIOP, and 10 mol % of CuCl were used. These reactions proceed through a direct activation of a carbon-silicon bond in alkynylsilanes by CuCl to generate the corresponding alkynylcopper species via transmetalation from silicon to copper. Mechanistic investigations on the reaction of alkynylsilanes with aryl bromides confirmed that the trimethylsilyl bromide generated in situ retarded both transmetalation steps between CuCl and alkynylsilane, and between palladium(II) species formed by oxidative addition and alkynylcopper species.
Perfluoro-tagged, phosphine-free palladium nanoparticles supported on silica gel: Application to alkynylation of aryl halides, Suzuki-Miyaura cross-coupling, and Heck reactions under aerobic conditions
Bernini, Roberta,Cacchi, Sandro,Fabrizi, Giancarlo,Forte, Giovanni,Petrucci, Francesco,Prastaro, Alessandro,Niembro, Sandra,Shafir, Alexandr,Vallribera, Adelina
supporting information; experimental part, p. 150 - 158 (2010/05/18)
The utilization of perfluoro-tagged palladium nanoparticles immobilized on fluorous silica gel through fluorous-fluorous interactions (Pd np-A/FSG) or through covalent bonding to silica gel (Pd np-B) in the alkynylation of aryl halides, in the Suzuki-Miyaura cross-coupling, as well as in the Heck reaction between methyl acrylate and aryl iodides is described. The reactions are carried out under aerobic and phosphine-free conditions with excellent to quantitative product yields in each case. The catalysts are easily recovered and reused several times without significant loss of activity. The alkynylation of aryl halides (under copper-free conditions) and the Suzuki-Miyaura cross-coupling are carried out in water. The Heck reaction of methyl acrylate with aryl iodides is best performed in MeCN. The utilization of Pdnp-B in the synthesis of 2,3-disubstituted indoles from 2-(alkynyl)trifluoroacetanilides and aryl halides is also reported.
Alkynylation of aryl halides with perfluoro-tagged palladium nanoparticles immobilized on silica gel under aerobic, copper- and phosphine-free conditions in water
Bernini, Roberta,Cacchi, Sandro,Fabrizi, Giancarlo,Forte, Giovanni,Petrucci, Francesco,Prastaro, Alessandro,Niembro, Sandra,Shafir, Alexandr,Vallribera, Adelina
supporting information; scheme or table, p. 2270 - 2273 (2009/09/26)
The utilization of perfluoro-tagged palladium nanoparticles immobilized on fluorous silica gel through fluorous-fluorous interactions (Pd np-A/FSG) or linked to silica gel by covalent bonds (Pd np-B) in the alkynylation of terminal a
Sila-sonogashira cross-coupling reactions of activated aryl chlorides with alkynylsilanes
Nishihara, Yasushi,Inoue, Eiji,Okada, Yoshiaki,Takagi, Kentaro
experimental part, p. 3041 - 3045 (2009/06/27)
The palladium/copper-cocatalyzed sila-Sonogashira cross-coupling reactions of activated aryl chlorides with alkynyl-silanes under strictly nonbasic conditions yield the unsymmetrical diarylethynes in moderate to good yields. Georg Thieme Verlag Stuttgart.
Benzene compounds
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Page/Page column 74, (2010/11/27)
The present invention provides novel benzene compounds presented by the following formulas, and analogs thereof, that exert an ACC activity-inhibiting effect that is effective in the treatment of obesity, hyperlipemia, fatty liver, hyperglycemia, impaired glucose tolerance, diabetes, diabetic complications (diabetic peripheral neuropathy, diabetic nephropathy, diabetic retinopathy, and diabetic macroangiopathy, hypertension, arteriosclerosis), hypertension, and arteriosclerosis.
