- Nickel/Photo-Cocatalyzed C(sp2)-H Allylation of Aldehydes and Formamides
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Herein we report a nickel/photo-cocatalyzed C(sp2)-H allylation of aldehydes and formamides wherein both allyl acetates and allyl alcohols can be used as the allylating agents. In this reaction, radical-type umpolung of the formyl moiety is enabled by tetrabutylammonium decatungstate as a hydrogen-atom-transfer photocatalyst, whereas nickel serves to cleave the C-O bond of allyl acetates or allyl alcohols. The synergistic effect of these two catalysts provides new access to various β,γ-unsaturated ketones and amides with high selectivities.
- Fan, Pei,Wang, Rui,Wang, Chuan
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supporting information
p. 7672 - 7677
(2021/10/12)
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- GPR52 Antagonist Reduces Huntingtin Levels and Ameliorates Huntington's Disease-Related Phenotypes
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GPR52 is an orphan G protein-coupled receptor (GPCR) that has been recently implicated as a potential drug target of Huntington's disease (HD), an incurable monogenic neurodegenerative disorder. In this research, we found that striatal knockdown of GPR52 reduces mHTT levels in adult HdhQ140 mice, validating GPR52 as an HD target. In addition, we discovered a highly potent and specific GPR52 antagonist Comp-43 with an IC50 value of 0.63 μM by a structure-activity relationship (SAR) study. Further studies showed that Comp-43 reduces mHTT levels by targeting GPR52 and promotes survival of mouse primary striatal neurons. Moreover, in vivo study showed that Comp-43 not only reduces mHTT levels but also rescues HD-related phenotypes in HdhQ140 mice. Taken together, our study confirms that inhibition of GPR52 is a promising strategy for HD therapy, and the GPR52 antagonist Comp-43 might serve as a lead compound for further investigation.
- Wang, Congcong,Zhang, Yu-Fang,Guo, Shimeng,Zhao, Quan,Zeng, Yanping,Xie, Zhicheng,Xie, Xin,Lu, Boxun,Hu, Youhong
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p. 941 - 957
(2020/11/30)
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- Synthesis of E-α,β-unsaturated ketones with complete stereoselectivity via sequential aldol-type/elimination reactions promoted by samarium diiodide or chromium dichloride
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E-α,β-Unsaturated ketones can be obtained with complete E-selectivity by a sequential reaction of dichloroketones with a variety of aldehydes. This transformation was promoted by SmI2, SmI2 in the presence of FeCl3 or CrCl2. The best results were obtained when CrCl2 was used as the metallating agent. A mechanism based on a successive aldol-type reaction and a β-elimination is proposed to explain these results. Georg Thieme Verlag Stuttgart.
- Concellón, José M.,Rodríguez-Solla, Humberto,Concellón, Carmen,Díaz, Pamela
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p. 837 - 840
(2007/10/03)
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- Radical allylation, vinylation, alkynylation, and phenylation reactions of α-halo carbonyl compounds with organoboron, organogallium, and organoindium reagents
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Allylic gallium and indium reagents are found to mediate radical allylation reactions of α-iodo or α-bromo carbonyl compounds. Treatment of benzyl bromoacetate with allylgallium, prepared from allylmagnesium chloride and gallium trichloride, in the presence of triethylborane provided benzyl 4-pentenoate in excellent yield. Addition of water as a co-solvent improved the yields of allylated products. Allylic indium reagents are also useful and can replace the gallium reagents. A diallylborane reagent can allylate an α-iodo ester in good yield. Alkenylation reactions of α-halo carbonyl compounds with alkenylindium proceeded via a radical process in the presence of triethylborane. Unactivated alkene moieties and styryl groups were introduced by this method. The carbon-carbon double bond geometry of the alkenylindiums was retained during the alkenylation. Preparation of an alkenylindium via a hydroindation of 1-alkyne and subsequent radical alkenylation established an efficient one-pot strategy. Radical alkynylations and phenylations with organoindium reagents are disclosed herein.
- Takami, Kazuaki,Usugi, Shin-Ichi,Yorimitsu, Hideki,Oshima, Koichiro
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p. 824 - 839
(2007/10/03)
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- Hypersensitive radical probe studies of Gif oxidations
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Hypersensitive probes were employed in mechanistic studies of Gif oxidations. The results indicate that, unlike the case in enzyme catalyzed hydroxylation reactions, diffusively free radicals are formed in Gif oxidations of these substrates.
- Newcomb, Martin,Simakov, Pavel A.,Park, Seung-Un
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p. 819 - 822
(2007/10/03)
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- Highly Chemoselective and Stereoselective Conjugate Addition of Benzyl Copper Reagents to α-Oxoketene Dithioacetals
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Benzyl copper reagents derived by transmetallation between benzylmagnesium chloride and Cu(I) species are shown to undergo conjugate addition - elimination with acyclic and cyclic α-oxoketene dithioacetals to afford the corresponding β-benzyl vinylogous t
- Mehta, Barun K.,Ila, Hiriyakkanavar,Junjappa, Hiriyakkanavar
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p. 1925 - 1928
(2007/10/02)
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