- Palladium-Catalyzed Regioselective Hydroaminocarbonylation of Alkynes to α,β-Unsaturated Primary Amides with Ammonium Chloride
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α,β-Unsaturated primary amides have found numerous applications in drug development, organic materials, and polymer sciences. However, the catalytic synthesis of α,β-unsaturated primary amides via carbonylation of alkynes has long been an elusive endeavor. Here, we report a novel palladium-catalyzed hydroaminocarbonylation of alkynes with NH4Cl as the amine source, enabling the highly chemo- and regioselective synthesis of α,β-unsaturated primary amides. A variety of alkynes, including aromatic alkynes, aliphatic alkynes, terminal alkynes, internal alkynes, as well as diynes with various functional groups, react well. The method turns the parasitic noncoordination ability of ammonium salts into a strategic advantage, enabling the gram-scale reaction to be performed in the presence of 0.05 mol % of catalyst with excellent selectivity.
- Ji, Xiaolei,Gao, Bao,Zhou, Xibing,Liu, Zongjian,Huang, Hanmin
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p. 10134 - 10141
(2018/07/09)
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- Adenylation Activity of Carboxylic Acid Reductases Enables the Synthesis of Amides
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Carboxylic acid reductases (CARs) catalyze the reduction of a broad range of carboxylic acids to aldehydes using the cofactors adenosine triphosphate and nicotinamide adenine dinucleotide phosphate, and have become attractive biocatalysts for organic synthesis. Mechanistic understanding of CARs was used to expand reaction scope, generating biocatalysts for amide bond formation from carboxylic acid and amine. CARs demonstrated amidation activity for various acids and amines. Optimization of reaction conditions, with respect to pH and temperature, allowed for the synthesis of the anticonvulsant ilepcimide with up to 96 % conversion. Mechanistic studies using site-directed mutagenesis suggest that, following initial enzymatic adenylation of substrates, amidation of the carboxylic acid proceeds by direct reaction of the acyl adenylate with amine nucleophiles.
- Wood, Alexander J. L.,Weise, Nicholas J.,Frampton, Joseph D.,Dunstan, Mark S.,Hollas, Michael A.,Derrington, Sasha R.,Lloyd, Richard C.,Quaglia, Daniela,Parmeggiani, Fabio,Leys, David,Turner, Nicholas J.,Flitsch, Sabine L.
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supporting information
p. 14498 - 14501
(2017/10/18)
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- A σ1 receptor pharmacophore derived from a series of N-substituted 4-azahexacyclo[5.4.1.02,6.03,10.0 5,9.08,11]dodecan-3-ols (AHDs)
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A library of N-substituted 4-azahexacyclo[5.4.1.02,6.0 3,10.05,9.08,11]dodecan-3-ols (AHDs) was synthesized and subjected to competition binding assays at σ1 and σ2 receptors, as well as off-target screening of representative members at 44 other common central nervous system (CNS) receptors, transporters, and ion channels. Excluding 3 low affinity analogs, 31 ligands demonstrated nanomolar Ki values for either σ receptor subtype. Several selective σ1 and σ2 ligands were discovered, with selectivities of up to 29.6 times for σ1 and 52.4 times for σ2, as well as several high affinity, subtype non-selective ligands. The diversity of structures and σ1 affinities of the ligands allowed the generation of a σ1 receptor pharmacophore that will enable the rational design of increasingly selective and potent σ1 ligands for probing σ1 receptor function.
- Banister, Samuel D.,Manoli, Miral,Doddareddy, Munikumar Reddy,Hibbs, David E.,Kassiou, Michael
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supporting information
p. 6053 - 6058
(2012/10/30)
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- The Heck reaction of β-arylacrylamides: An approach to 4-aryl-2-quinolones
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The Heck reaction of β-arylacrylamides with aryl iodides afforded the corresponding vinylic substitution products usually in high yields. The nature of β-substituents, aryl iodides and substituents at the nitrogen atom influences the stereochemical outcome. N,N-Dimethyl-β-arylacrylamides gave vinylic substitution products with higher stereoselectivity than the corresponding N-unsubstituted β-arylacrylamides. β-Arylacrylamides containing ortho-substituents led to the formation of only one stereoisomer. The procedure was used to prepare 4-aryl-2-quinolones from β-(obromophenyl) acrylamide through a sequential Heck reaction and copper-catalyzed cyclization process. Georg Thieme Verlag Stuttgart.
- Bernini, Roberta,Cacchi, Sandro,De Salve, Ilse,Fabrizi, Giancarlo
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p. 2947 - 2952
(2008/02/12)
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