17094-34-7Relevant academic research and scientific papers
Radical Aza-Cyclization of α-Imino-oxy Acids for Synthesis of Alkene-Containing N-Heterocycles via Dual Cobaloxime and Photoredox Catalysis
Tu, Jia-Lin,Liu, Jia-Li,Tang, Wan,Su, Ma,Liu, Feng
supporting information, p. 1222 - 1226 (2020/02/15)
Nitrogen-containing heterocycles are prevalent in both naturally and synthetically bioactive molecules. We report herein an unprecedented protocol for radical aza-cyclization of α-imino-oxy acids with pendant alkenes via synergistic photoredox and cobaloxime catalysis. With or without alkenes as the intermolecular cross-coupling partners, the transformation provides a variety of corresponding alkene-containing dihydropyrrole products in satisfactory yields. In the presence of external alkenes, the tandem reaction generates E-selective coupling products with excellent chemo- and stereoselectivity.
Modular Tuning of Electrophilic Reactivity of Iridium Nitrenoids for the Intermolecular Selective α-Amidation of β-Keto Esters
Lee, Minhan,Jung, Hoimin,Kim, Dongwook,Park, Jung-Woo,Chang, Sukbok
, p. 11999 - 12004 (2020/08/06)
We report herein an Ir-catalyzed intermolecular amino group transfer to β-keto esters (amides) to access α-aminocarbonyl products with excellent chemoselectivity. The key strategy was to engineer electrophilicity of the putative Ir-nitrenoids by tuning electronic property of the κ2-N,O chelating ligands, thus facilitating nucleophilic addition of enol π-bonds of 1,3-dicarbonyl substrates.
Enantioselective Mannich reaction of β-keto esters with aromatic and aliphatic imines using a cooperatively assisted bifunctional catalyst
Neuvonen, Antti J.,Pihko, Petri M.
supporting information, p. 5152 - 5155 (2015/01/08)
An efficient urea-enhanced thiourea catalyst enables the enantioselective Mannich reaction between β-keto esters and N-Boc-protected imines under mild conditions and minimal catalyst loading (1-3 mol %). Aliphatic and aromatic substituents are tolerated on both reaction partners, affording the products in good enantiomeric purity. The corresponding β-amino ketones can readily be accessed via decarboxylation without loss of enantiomeric purity.
Ligand steric and electronic effects on β-ketiminato neutral nickel(II) olefin polymerization catalysts
Song, Dong-Po,Shi, Xin-Cui,Wang, Yong-Xia,Yang, Ji-Xing,Li, Yue-Sheng
experimental part, p. 966 - 975 (2012/04/10)
A series of novel neutral nickel complexes 3a-g and 4a-d bearing the β-ketiminato ligands [(2,6-iPr2C6H 3)N=CHCHC(R)O]Ni(R′)(L) (for 3a-g, R′ = Me, L = Py, and R = tBu (3a), Ph (3b), 1-naphthyl (3c), 9-anthryl (3d), PhNMe 2(p) (3e), PhOMe(p) (3f), PhCF3(p) (3g); for 4a-d, R′ = Ph, L = PPh3, and tBu (4a), Ph (4b), 1-naphthyl (4c), 9-anthryl (4d)) have been synthesized and characterized. The molecular structures of 3b-d,f,g and 4a,c were further confirmed by X-ray crystallographic analysis. These complexes were employed in ethylene polymerization to systematically investigate ligand steric and electronic effects on the catalytic properties, including activity, molecular weight (MW), and branching number of the polyethylene obtained. The complexes bearing more bulky ligands showed higher activities and produced more branched polyethylene. Electron-deficient ligands were found to increase the catalytic activity, decrease the MW, and enhance the branching content of the polyethylene. In addition, phosphine NiII-Ph complexes 4a-d proved to be more active than the corresponding pyridine NiII-Me complexes 3a-d, probably due to the easier dissociation of PPh3 relative to a pyridine from a nickel center.
Expeditious solid-phase synthesis of pyrazoledicarboxylic acid derivatives by functionalization of resin-bound cyanoformate
Morelli, Carlo F.,Saladino, Alberto,Speranza, Giovanna,Manitto, Paolo
, p. 4621 - 4627 (2007/10/03)
Esterification of the Wang resin 5 with the monoamide of oxalic acid (oxamic acid, 7) followed by dehydration of the amide function furnishes the resin-bound cyanoformate 9, which can be elaborated by zinc-catalyzed reaction with β-keto esters. The obtained enamino keto diesters 10a-d react with hydrazines affording, after removal from the solid support, fully substituted pyrazoledicarboxylic acids 12a-n. Optimization of the above sequence and the solid-phase synthesis of a small test-library of 1,5-disubstituted pyrazole-3,4-dicarboxylic acid derivatives are described. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
A general synthesis of dioxolenone prodrug moieties
Sun, Chong-Qing,Cheng, Peter T.W.,Stevenson, Jay,Dejneka, Tamara,Brown, Baerbel,Wang, Tammy C.,Robl, Jeffrey A.,Poss, Michael A.
, p. 1161 - 1164 (2007/10/03)
A general method for the synthesis of dioxolenone prodrug moieties from appropriately substituted β-ketoesters is described. This novel and versatile sequence allows for the synthesis of alkyl- or aryl-substituted dioxolenone alcohols 8 or bromides 9. Coupling of the bromides 9 to prepare bis-dioxolenone phosphonate prodrug esters is also presented.
Process for producing pivaloyl-acetic acid ester
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, (2008/06/13)
A process for producing a pivaloylacetic acid ester comprises reacting pivaloyl chloride with an acetoacetic acid ester of an alkyl group having 1 to 4 carbon atoms in the presence of at least one nitrogen-containing basic compound (a) selected from among pyridine compounds, N,N-dialkylanilines and imidazole compounds and from 0.01 to 0.5 mole equivalent, based on the pivaloyl chloride, of a magnesium compound (b) to thereby prepare a pivaloylacetoacetic acid ester and then alcholyzing or alkali-hydrolyzing the pivaloylacetoacetic acid ester to thereby give a pivaloylacetic acid ester having a high purity at a low cost.
The Reformatsky Reaction of 1-Acyl-3,5-dimethylpyrazoles. A Convenient Preparation of 4-Amino-3-oxoalkanoic Acid Derivatives
Kashima, Choji,Kita, Isanobu,Takahashi, Katsumi,Hosomi, Akira
, p. 723 - 726 (2007/10/02)
The conversion of N-acylpyrazoles into β-keto esters was accomplished efficiently by the treatment with α-bromo esters and zinc dust.Using this Reformatsky reaction of N-acylpyrazoles, 4-(protected amino)-3-oxoalkanoic acid derivatives were conveniently prepared as the key intermediates in the synthesis of statines.
