- Quinim: A New Ligand Scaffold Enables Nickel-Catalyzed Enantioselective Synthesis of α-Alkylated ?-Lactam
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Herein, we report a nickel-catalyzed reductive cross-coupling reaction of easily accessible 3-butenyl carbamoyl chloride with primary alkyl iodide to access the chiral α-alkylated pyrrolidinone with broad substrate scope and high enantiomeric excess. The current art of synthesis still remains challenging on the enantioselective α-monoalkylation of pyrrolidinones. The newly designed chiral 8-quinoline imidazoline ligand (Quinim) is crucial for maintaining the reactivity and enantioselectivity to ensure the reductive cyclization of monosubstituted alkenes for unprecedented synthesis of chiral non-aromatic heterocycles.
- Chen, Yifeng,Qu, Jingping,Wu, Xianqing
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supporting information
p. 15654 - 15660
(2020/10/18)
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- Scalable and Phosphine-Free Conversion of Alcohols to Carbon-Heteroatom Bonds through the Blue Light-Promoted Iodination Reaction
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One of the fundamental and highly valuable transformations in organic chemistry is the nucleophilic substitution of alcohols. Traditionally, these reactions require strategies that employ stoichiometric hazardous reagents and are associated with difficulty in purification of the by-products. To overcome these challenges, here, we report a simple route toward the diverse conversion of alcohols via an SN2 pathway, in which blue light-promoted iodination is used to form alkyl iodide intermediates from simple unreactive alcohols. The scope of the process tolerates a range of nucleophiles to construct C-N, C-O, C-S, and C-C bonds. Furthermore, we also demonstrate that this method can be used for the preparation and late-stage functionalization of pharmaceuticals, as highlighted by the syntheses of thiocarlide, butoxycaine, and pramoxine.
- Liu, Bin,Elder, W. Zachary,Miyake, Garret M.
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p. 3717 - 3727
(2020/03/04)
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- Visible-Light-Promoted Remote C-H Functionalization of o-Diazoniaphenyl Alkyl Sulfones
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Visible-light irradiation of ortho-diazoniaphenyl alkyl sulfones in the presence of Ru(bpy)32+ results in remote Csp3-H functionalization. Key mechanistic steps in these processes involve intramolecular hydrogen atom transfer from Csp3-H bonds to aryl radicals to generate alkyl/benzyl radicals. Subsequent polar crossover occurs by single-electron oxidation of the alkyl/benzyl radicals to carbenium ions that then intercept nucleophiles. We have developed remote hydroxylations, etherifications, an amidation, and C-C bond formation processes using this strategy.
- Du, Shaofu,Kimball, Elizabeth Ann,Ragains, Justin R.
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supporting information
p. 5553 - 5556
(2017/10/25)
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- Improved syntheses of high hole mobility phthalocyanines: A case of steric assistance in the cyclo-oligomerisation of phthalonitriles
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It has been shown that the base-initiated cyclo-oligomerisation of phthalonitriles is favoured by bulky α-substituents making it possible to obtain the metal-free phthalocyanine directly and in high yield. The phthalocyanine with eight α-isoheptyl substituents gives a high time-of-flight hole mobility of 0.14 cm2·V -1·s-1 within the temperature range of the columnar hexagonal phase, that is 169-189 °C.
- Tate, Daniel J.,Anemian, Remi,Bushby, Richard J.,Nanan, Suwat,Warriner, Stuart L.,Whitaker, Benjamin J.
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experimental part
p. 120 - 128
(2012/02/14)
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- 2-substituted-(2SR)-2-amino-2-((1SR,2SR)-2-carboxycycloprop-1- yl)glycines as potent and selective antagonists of group II metabotropic glutamate receptors. 1. Effects of alkyl, arylalkyl, and diarylalkyl substitution
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In this paper, we describe the synthesis of a series of α-substituted analogues of the potent and selective group II metabotropic glutamate receptor (mGluR) agonist (1S,1'S,2'S)-carboxy-cyclopropylglycine (2, L-CCG 1). Incorporation of a substituent on the amino acid carbon converted the agonist 2 into an antagonist. All of the compounds were prepared and tested as a aeries of four isomers, i.e., two racemic diastereomers. We explored alkyl substitution, both normal and terminally branched; phenylalkyl and diphenylalkyl substitution; and a variety of aromatic and carbocyclic surrogates for phenyl. Affinity for group II mGluRs was measured using [3H]glutamic acid (Glu) binding in rat forebrain membranes. Antagonist activity was confirmed for these compounds by measuring their ability to antagonize (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid-induced inhibition of forskolin-stimulated cyclic-AMP in RGT cells transfected with human mGluR2 and mGluR3. We found that while alkyl substitution provided no increase in affinity relative to 2, phenylethyl and diphenylethyl substitution, as in 105 and 109, respectively, were quite beneficial. The affinity of 109 was further enhanced when the two aromatic rings were joined by an oxygen or sulfur atom to form the tricyclic xanthylmethyl and thioxanthylmethyl amino acids 113 and 114, respectively. Amino acid 113, with an IC50 of 0.010 μM in the [3H]Glu binding assay, was 52-fold more potent than 2, whose IC50 was 0.47 μM.
- Ornstein, Paul L.,Bleisch, Thomas J.,Arnold, M. Brian,Wright, Rebecca A.,Johnson, Bryan G.,Schoepp, Darryle D.
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p. 346 - 357
(2007/10/03)
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- Process for preparation of carboxylic acid ester containing fluorine
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Process for the preparation of carboxylic acid ester containing fluorine comprises the reaction of the reaction mixture obtained by the reaction of an organic halogen compound containing fluorine expressed by a general formula, , X - Rf- X′, , (in which, X and X′ independently stand for halogen atoms and Rfis an optionally fluorinated hydrocarbon) with carbon dioxide in the presence of zinc, with a halogenated hydrocarbon expressed by a general formula,, RY, , (in which R is an optionally fluorinated hydrocarbon and Y is a chlorine, bromine or iodine atom).
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- Chemical process
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Novel bis(3',5'-mono or dihydrocarbyl-4'-hydroxybenzyl)-1,3-diketones are prepared by reacting a (3',5'-mono or dihydrocarbyl-4'-hydroxybenzyl)-1,3-diketone with an N,N-dihydrocarbyl-2,6-mono or dihydrocarbyl-4-aminomethylphenol and an alkyl halide in the presence of an alkaline earth metal halide. The products are useful as antioxidants.
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- Chemical process for preparing 1,3-diketones
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Novel (3',5'-dihydrocarbyl-4'-hydroxybenzyl)-1,3-diketones are prepared by reacting an N,N-dihydrocarbyl-2,6-dihydrocarbyl-4-aminomethylphenol with a 1,3-diketone and an alkyl halide in the presence of an alkali or an alkaline earth metal hydride. The products are useful as antioxidants.
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- Chemical process
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Novel 2,4-dihydrocarbylspiro[5.5]undeca-1,4,8-trien-3-one compounds are prepared by reacting an N,N-dihydrocarbyl,2,6-dihydrocarbyl-4-aminomethylphenol with a conjugated diene and an alkyl halide in a liquid solvent medium.
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