- Regioselective differentiation of vicinal methylene C-H bonds enabled by silver-catalysed nitrene transfer
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Silver-catalyzed nitrene insertion enables the formation of benzosultams in good yield and with regioselectivity complementary to other transition metal nitrene-transfer catalysts. Preferential formation of six-membered benzosultam rings predominates for alkyl-substituted benzenesulphonamide precursors. Ligand-controlled tunability is also achieved for benzenesulphonamides with γ-branched alkyl substituents. Mechanistic probes suggest that the reaction pathway differs depending on whether a α (benzylic) or β (homobenzylic) C-H bond undergoes amidation, as well as the catalyst identity.
- Scamp, Ryan J.,Scheffer, Bradley,Schomaker, Jennifer M.
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supporting information
p. 7362 - 7365
(2019/06/27)
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- Palladium-catalyzed double-bond migration of unsaturated hydrocarbons accelerated by tantalum chloride
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The operationally simple palladium-catalyzed double-bond migration without heteroatom-containing coordinating functional groups is described. Addition of TaCl5 as a second catalyst greatly enhanced the migration efficiency to provide β-alkylsty
- Murai, Masahito,Nishimura, Kengo,Takai, Kazuhiko
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supporting information
p. 2769 - 2772
(2019/03/23)
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- Anodic benzylic C(sp3)-H amination: Unified access to pyrrolidines and piperidines
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An electrochemical aliphatic C-H amination strategy was developed to access the important heterocyclic motifs of pyrrolidines and piperidines within a uniform reaction protocol. The mechanism of this unprecedented C-H amination strategy involves anodic C-H activation to generate a benzylic cation, which is efficiently trapped by a nitrogen nucleophile. The applicability of the process is demonstrated for 40 examples comprising both 5- and 6-membered ring formations.
- Herold, Sebastian,Bafaluy, Daniel,Mu?iz, Kilian
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supporting information
p. 3191 - 3196
(2018/07/29)
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- Novel thiourea derivatives and the pharmaceutical compositions containing the same
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The present invention relates to novel thiourca derivatives as a modulator for vanilloid receptor (VR) and the phar- maceutical compositions containing the same. As diseases associated with the activity of vanilloid receptor, pain acute pain, chronic pain, neuropathic pain, post-operative pain, migraine, arthralgia, neuropathies, nerve injury, diabetic neuropathy, neurodegeneration, neurotic skin disorder, stroke, urinary bladder hypersensitiveness, irritable bowel syndrome, a respiratory disorder such as asthma or chronic obstructive pulmonary disease, irritation of skin, eye or mucous membrane, fervescence, stomach-duodenal ulcer, inflam- matory bowel disease and inflammatory diseases can be enumerated. The present invention provides a pharmaceutical composition for prevention or treatment of these diseases.
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- Dendrimer poly(ethylenimine)s linked to β-cyclodextrin
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β-Cyclodextrin was attached to two dendrimer poly(ethylenimine)s. The resulting cyclodextrin-containing dendrimers, CD-I and CD-II, can be considered either as dendrimers equipped with specific binding sites or as cyclodextrins containing amino groups around the cavities. Amines of CD-I and CD-II remarkably resisted protonation compared with those of the parent dendrimers. A compact conformation of CD-I or CD-II in which the dendrimer wraps itself around the cyclodextrin is proposed as a conformation consistent with the suppressed protonation. Esters containing t-butylphenyl groups were complexed by CD-I and CD-II and underwent fast deacylation. Kinetic data were obtained with several ester substrates, which revealed that two amino groups located in the vicinity of each cyclodextrin cavity of CD-I or CD-II participated as nucleophiles. In addition, optimum reactivity was attained when the spacer connecting the t-butylphenyl and the ester groups was -O- CH2- or -CH=CH-. Structures of the active sites for the accelerated deacylation of esters were elucidated on the basis of the kinetic data.
- Suh, Junghun,Hah, Sang Soo,Lee, Sang Hee
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