124401-38-3Relevant articles and documents
α-Unsubstituted Pyrroles by NHC-Catalyzed Three-Component Coupling: Direct Synthesis of a Versatile Atorvastatin Derivative
Fleige, Mirco,Glorius, Frank
, p. 10773 - 10776 (2017)
A practical one-pot cascade reaction protocol provides direct access to valuable 1,2,4-trisubstituted pyrroles. The process involves an N-heterocyclic carbene (NHC)-catalyzed Stetter-type hydroformylation using glycolaldehyde dimer as a novel C1 building-block, followed by a Paal-Knorr condensation with primary amines. The reaction makes use of simple and commercially available starting-materials and catalyst, an important feature regarding applicability and utility. Low catalyst loading under mild reaction conditions afforded a variety of 1,2,4-substituted pyrroles in a transition-metal-free reaction with high step economy and good yields. This methodology is applied in the synthesis of a versatile Atorvastatin precursor, in which a variety of modifications at the pyrrole core structure are possible.
Ru-NHC-Catalyzed Asymmetric Hydrogenation of 2-Quinolones to Chiral 3,4-Dihydro-2-Quinolones
Daniliuc, Constantin,Glorius, Frank,Hu, Tianjiao,Lückemeier, Lukas
supporting information, p. 23193 - 23196 (2021/09/25)
Direct enantioselective hydrogenation of unsaturated compounds to generate chiral three-dimensional motifs is one of the most straightforward and important approaches in synthetic chemistry. We realized the Ru(II)-NHC-catalyzed asymmetric hydrogenation of 2-quinolones under mild reaction conditions. Alkyl-, aryl- and halogen-substituted optically active dihydro-2-quinolones were obtained in high yields with moderate to excellent enantioselectivities. The reaction provides an efficient and atom-economic pathway to construct simple chiral 3,4-dihydro-2-quinolones. The desired products could be further reduced to tetrahydroquinolines and octahydroquinolones.
Preparation method of atorvastatin calcium isomers
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Paragraph 0022-0034; 30051-0052, (2018/09/11)
The invention relates to a preparation method of atorvastatin calcium isomers [R-(R*,R*)]-2-(3-fluorophenyl)-beta,delta-dihydroxy-5-(1-methylethyl)-2-phenyl-4-[(aniline)carbonyl]-1H-pyrrole-1-calciumenanthate salt (IMP-1 for short) and [R-(R*,R*)]-3-(2-fluorophenyl)-beta, delta-dihydroxyl -5-(1-Methylethyl)-3-phenyl-4-[(anilino)carbonyl]-1H-pyrrole-1- calcium enanthate salt (IMP-2 for short). According to the preparation method, a preparation method of a reference substance is provided for the quality research of drugs, and an important guiding significance is provided for the safe medicationof atorvastatin calcium.
Synthesis of Indoles and Pyrroles Utilizing Iridium Carbenes Generated from Sulfoxonium Ylides
Vaitla, Janakiram,Bayer, Annette,Hopmann, Kathrin H.
supporting information, p. 4277 - 4281 (2017/04/03)
Metal carbenes can undergo a myriad of synthetic transformations. Sulfur ylides are potential safe precursors of metal carbenes. Herein, we report cascade reactions that involve carbenoids derived from sulfoxonium ylides for the efficient and regioselective synthesis of indoles and pyrroles. The tandem action of iridium and Br?nsted acid catalysts enables rapid assembly of the heterocycles from unmodified anilines or readily accessible enamines under microwave irradiation. The key mechanistic steps are the catalytic transformation of the sulfoxonium ylide into an iridium–carbene complex, followed by N?H or C?H functionalization of an aniline or enamine, respectively, and a final acid-catalyzed cyclization. The present method was successfully applied to the synthesis of the densely functionalized pyrrole subunit of atorvastatin.