- Reactions of difluorocarbene with organozinc reagents
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Reactions of difluorocarbene with benzyl and alkylzinc halides leading to fluorinated organozinc species have been described. The generated α-difluorinated organozinc reagents are reasonably stable in solution and can be quenched with external electrophiles (iodine, bromine, proton), affording compounds containing the CF2 fragment.
- Levin, Vitalij V.,Zemtsov, Artem A.,Struchkova, Marina I.,Dilman, Alexander D.
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p. 917 - 919
(2013/03/28)
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- Indium-catalyzed radical reductions of organic halides with hydrosilanes
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(Equation Presented) The In(OAc)3-catalyzed reaction of bromo- and iodoalkanes with PhSiH3 in THF at 70°C gave dehalogenated alkanes in good to high yields. In the presence of Et3B and air, the reduction proceeded smoothly at 30°C. When 2,6-lutidine and air were used as additives, the In(OAc)3-catalyzed system enabled an efficient reduction of simple and functionalized iodoalkanes in EtOH. Catalytic use of GaCl3 was found to be effective in the reduction of haloalkanes with poly(methylhydrosiloxane) (PMHS). These catalytic reductions probably involve a radical chain mechanism in which indium or gallium hydride species work as the actual reductants.
- Miura, Katsukiyo,Tomita, Mitsuru,Yamada, Yusuke,Hosomi, Akira
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p. 787 - 792
(2007/10/03)
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- Synthesis and structure-activity relationships of soluble 7-substituted 3-(3,5-dimethoxyphenyl)-1,6-naphthyridin-2-amines and related ureas as dual inhibitors of the fibroblast growth factor receptor-1 and vascular endothelial growth factor receptor-2 tyrosine kinases
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7-Substituted 3-aryl-1,6-naphthyridine-2,7-diamines and related 2-ureas are inhibitors of fibroblast growth factor receptor-1 (FGFR-1) and vascular endothelial growth factor receptor-2 (VEGFR-2). 3-(3,5-Dimethoxyphenyl) and 3-phenyl analogues were prepared from 7-acetamido-2-teri-butylureas by alkylation with benzyl ω-iodoalkyl ethers, debenzylation, and animation, followed by selective cleavage of the 7-N-acetamide. 3-(2,6-Dichlorophenyl) analogues were prepared from the 7-fluoro-2-amine by displacement with substituted alkylamines, followed by selective acylation of the resulting substituted naphthyridine-2,7-diamines with alkyl isocyanates. The 3-(3,5-dimethoxyphenyl) derivatives were low nanomolar inhibitors of both FGFR and VEGFR and were highly selective (>100-fold) over PDGFR and c-Src. Variations in the base strength or spatial position of the 7-side chain base had only small effects on the potency (5-fold) or selectivity (20-fold). The 3-(2,6-dichlorophenyl)-2-urea derivatives were slightly less active against VEGFR and less selective, being more effective against PDGFR (ca. 10-fold) and c-Src (ca. 500-fold). The 3-(3,5-dimethoxyphenyl)-1,6-naphthyridines were generally more potent than the corresponding pyrido[2,3-d]pyrimidines against both VEGFR and FGFR (2- to 20-fold), with only slightly increased PDGFR and c-Src activity. The 3-(3,5-dimethoxyphenyl)-1,6-naphthyridine 2-ureas were also low nanomolar inhibitors of the growth of human umbilical vein endothelial cells (HUVECs) stimulated by serum, FGF, or VEGF, at concentrations that did not affect the growth of representative tumor cell lines, and were more (3- to 65-fold) potent than the corresponding pyrido[2,3-d]pyrimidines.
- Thompson, Andrew M.,Delaney, Amy M.,Hamby, James M.,Schroeder, Mel C.,Spoon, Teresa A.,Crean, Sheila M.,Showalter, H. D. Hollis,Denny, William A.
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p. 4628 - 4653
(2007/10/03)
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