- Palladium-Catalyzed C(sp3)-H Nitrooxylation with tert-Butyl Nitrite and Molecular Oxygen
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Herein, we report a Pd(II)-catalyzed nitrooxylation of unactivated methyl C(sp3)-H bonds using commercial available and easily manageable tert-butyl nitrite as the precursor of ONO2 radical under aerobic conditions. Environmentally benign molecular oxygen is used to initiate the generation of active radical reactant; it is also used as the terminal oxidant. A broad range of nitrooxylated aliphatic carboxamides were prepared in moderate to good yields under mild conditions.
- Han, Ye-Qiang,Li, Bo,Shi, Bing-Feng,Yang, Xu
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supporting information
p. 9719 - 9723
(2020/12/21)
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- 1-Aminopyridinium Ylides as Monodentate Directing Groups for sp3 C-H Bond Functionalization
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1-Aminopyridinium ylides are efficient directing groups for palladium-catalyzed β-arylation and alkylation of sp3 C-H bonds in carboxylic acid derivatives. The efficiency of these directing groups depends on the substitution at the pyridine moiety. The unsubstituted pyridine-derived ylides allow functionalization of primary C-H bonds, while methylene groups are unreactive in the absence of external ligands. 4-Pyrrolidinopyridine-containing ylides are capable of C-H functionalization in acyclic methylene groups in the absence of external ligands, thus rivaling the efficiency of the aminoquinoline directing group. Preliminary mechanistic studies have been performed. A cyclopalladated intermediate has been isolated and characterized by X-ray crystallography, and its reactivity was studied.
- Le, Ky Khac Anh,Nguyen, Hanh,Daugulis, Olafs
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supporting information
p. 14728 - 14735
(2019/10/11)
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- Developing Pd(II) catalyzed double sp3 C-H alkoxylation for synthesis of symmetric and unsymmetric acetals
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An effective Pd(II) catalyzed double unactivated C(sp3)-H alkoxylation has been developed to prepare both symmetric and unsymmetric acetals. This new reaction demonstrates good functional group tolerance, excellent reactivity, and high yields. A variety of novel acetals can be readily accessed via this new method. (Chemical Equation Presented).
- Zong, Yu,Rao, Yu
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supporting information
p. 5278 - 5281
(2015/01/09)
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- Catalytic asymmetric hydrogenation of α-CF3- or β-CF3-Substituted acrylic acids using Rhodium(I) complexes with a combination of chiral and achiral ligands
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Only the mixture works! Acrylic acid derivatives with CF3 substituents in α or β position were efficiently hydrogenated in the presence of a RhI complex with a chiral secondary phosphine oxide (SPO; see scheme) and an achiral Ph3P as ligands. The corresponding propanoic acid derivatives were obtained with generally high conversion (>99 %) and high enantioselectivity (92->99 %). Copyright
- Dong, Kaiwu,Li, Yang,Wang, Zheng,Ding, Kuiling
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supporting information
p. 14191 - 14195
(2014/01/06)
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- Carbamoyl derivatives
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The present invention concerns novel carbamoyl derivatives of formula I, set out herein, which antagonize the pharmacological actions of one or more of the arachidonic acid metabolites known as leukotrienes, making them useful whenever such antagonism is desired, such as in the treatment of those diseases in which leukotrienes are implicated, for example, in the treatment of allergic or inflammatory diseases, or of endotoxic or traumatic shock conditions. The invention also provides pharmaceutical compositions containing the novel derivatives for use in such treatments, methods for their use and processes and intermediates for the manufacture of the novel derivatives.
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- Synthesis, Structure-Activity Relationships, and Pharmacological Evaluation of a Series of Fluorinated 3-Benzyl-5-indolecarboxamides: Identification of 4--1-methylindol-3-yl>methyl>-3-methoxy-N-benzamide, ...
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The continued exploration of a series of 3-(arylmethyl)-1H-indole-5-carboxamides by the introduction of fluorinated amide substituents has resulted in the discovery of 4--1-methylindol-3-yl>methyl>-3-methoxy-N-benzamide (38p, ZENECA ZD 3523), which has been chosen for clinical evaluation.This compound exhibited a Ki of 0.42 nM for displacement of LTD4 on guinea pig lung membranes, a pKB of 10.13 +/- 0.14 versus LTE4 on guinea pig trachea, and an oral ED50 of 1.14 μmol/kg opposite LTD4-induced bronchoconstriction in guinea pigs.The R enantiomer was found to be modestly more potent than the S enantiomer 38o.Modification of the amide substituent to afford achiral compounds was unsuccessful in achieving comparable levels of activity.Profiling of 38p opposite a variety of functional assays has demonstrated the selectivity of this compound as a leukotriene receptor antagonist.The enantioselective synthesis of 38p, which employed a diastereoselective alkylation of (4R,5S)-3-(1-oxo-4,4,4-trifluorobutyl)-4-methyl-5-phenyl-2-oxazolidinone (27) as the key step to establish the chirality of the amide substituent, provided an efficient route for generating 38p in >99percent enantiomeric purity.
- Jacobs, Robert T.,Bernstein, Peter R.,Cronk, Laura A.,Vacek, Edward P.,Newcomb, Lisa F.,et al.
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p. 1282 - 1297
(2007/10/02)
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- Process for preparing (2R)-methyl-4,4,4-trifluorobutylamine
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A process for the preparation of (2R)-methyl-4,4,4-trifluorobutylamine, or an acid addition salt thereof which comprises a) acylating an optically active amine with 2-methyl-4,4,4-trifluorobutanoic acid or a reactive derivative thereof to afford a butyramide; b) separating (R)-diastereomeric butyramide from (S)-diastereomeric butyramide; and c) converting the (R)-diastereomeric butyramide into the desired (2R)-methyl-4,4,4-trifluorobutylamine, or an acid addition salt thereof. The product may be acylated with a carboxylic acid of formula III STR1 wherein U is carboxy, or a reactive derivative thereof to afford (R)-4-[5-(N-[4,4,4-trifluoro-2-methylbutyl]carbamoyl)-1-methylindol-3-yl-methyl]-3-methoxy-N-o-tolylsulphonylbenzamide. The indole is useful as a leukotriene antagonist, for example in the treatment of asthma or allergic rhinitis.
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