- Utilization of a Trimethylsilyl Group as a Synthetic Equivalent of a Hydroxyl Group via Chemoselective C(sp3)-H Borylation at the Methyl Group on Silicon
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A conversion of trimethylsilylalkanes into the corresponding alcohols is established based on an iridium-catalyzed, chemoselective C(sp3)-H borylation of the methyl group on silicon. The (borylmethyl)silyl group formed by C(sp3)-H borylation is treated with H2O2/NaOH, and the resulting (hydroxymethyl)silyl group is converted into a hydroxyl group by Brook rearrangement, followed by oxidation of the resulting methoxysilyl group under Tamao conditions. An alternative route proceeding through the formylsilyl group formed from a (hydroxymethyl)silyl group by Swern oxidation is also established. The method is applicable to substituted trimethylsilylcycloalkanes and 1,1-dimethyl-1-silacyclopentane for conversion into the corresponding stereodefined cycloalkyl alcohols and 1,4-butanediol.
- Torigoe, Takeru,Ohmura, Toshimichi,Suginome, Michinori
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p. 2943 - 2956
(2017/03/23)
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- Fluorinated β-nitro amines by a selective ZrCl4-catalyzed aza-Henry reaction of (E)-trifluoromethyl aldimines
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ZrCl4 was found to be an ideal catalyst to promote aza-Henry reactions between trifluoromethyl aldimines and some nitro alkanes giving new fluorinated β-nitro amines. The reaction is strongly influenced by the CF3 group, the yield by
- Fioravanti, Stefania,Pellacani, Lucio,Vergari, Maria Cecilia
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supporting information
p. 8207 - 8210,4
(2012/12/12)
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- Discovery of substituted biphenyl imidazoles as potent, bioavailable bombesin receptor subtype-3 agonists
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We report SAR studies on a novel non-peptidic bombesin receptor subtype-3 (BRS-3) agonist lead series derived from high-throughput screening hit RY-337. This effort led to the discovery of compound 22e with significantly improved potency at both rodent and human BRS-3.
- He, Shuwen,Dobbelaar, Peter H.,Liu, Jian,Jian, Tianying,Sebhat, Iyassu K.,Lin, Linus S.,Goodman, Allan,Guo, Cheng,Guzzo, Peter R.,Hadden, Mark,Henderson, Alan J.,Ruenz, Megan,Sargent, Bruce J.,Yet, Larry,Kelly, Theresa M.,Palyha, Oksana,Kan, Yanqing,Pan, Jie,Chen, Howard,Marsh, Donald J.,Shearman, Lauren P.,Strack, Alison M.,Metzger, Joseph M.,Feighner, Scott D.,Tan, Carina,Howard, Andrew D.,Tamvakopoulos, Constantin,Peng, Qianping,Guan, Xiao-Ming,Reitman, Marc L.,Patchett, Arthur A.,Wyvratt Jr., Matthew J.,Nargund, Ravi P.
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scheme or table
p. 1913 - 1917
(2010/07/02)
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- Catalytic and stoichiometric Lewis acid participation in aldehyde ene cyclisations
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Racemic 2-isopropyl-2-methylhex-5-enal has been synthesised in order to probe ene cyclisations leading to menthol analogues. The objective was first to discover catalytic conditions for preferential cyclisation to the menthol rather than the neomenthol series and then to develop (dynamic) kinetic resolution procedures which afforded a single enantiomer of product. It was found that catalytic quantities of both Me2AlCl and a bulky methyl-aluminium bis(phenoxide) reagent gave products attributed to a Meerwein-Pondorff-Verley reaction. In this the aldehyde is reduced to a primary alcohol and the ene product oxidised to the corresponding α,β-unsaturated ketone. By contrast, a related bulky chloroaluminium reagent catalysed the ene cyclisation cleanly, but preferentially to the undesired neomenthyl stereoisomer.
- Braddock, D. Christopher,Brown, John M.
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p. 741 - 756
(2007/10/03)
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