5,10-Dihydroindeno[1,2-]indole has served as an important starting precursor for BARAC-fluor reagent in medicinal chemistry. Herein, an unprecedented -TsOH assisted intramolecular C2-arylation of NH-indoles via C(sp)-CN/C(sp)-H coupling, offering a series of 5,10-dihydroindeno[1,2-]indoles with moderate to good yields, has been showcased under redox-neutral conditions. Furthermore, successful scalability and synthetic applications highlight the practical nature of the method.
View Article and Find Full Text PDFHerein, a one-pot desulfonylative protocol enabled by copper(II)/zinc(II) salts to access pyrrolo[2,3-]quinolines in good to excellent yields from 2-carbonylanilines and ynamide-derived buta-1,3-diynes has been reported. Significantly, various 2-carbonylanilines carrying reactive functional groups are well tolerated. Moreover, a gram-scale synthesis and synthetic application highlight the practical utility of the current protocol.
View Article and Find Full Text PDFA straightforward and atom-economical one-pot protocol catalyzed by gold(I) and zinc(II) for the synthesis of amine-substituted diaryl[,][1,6]naphthyridines from two different aromatic nitriles has been showcased. This dual-catalytic strategy is highly efficient, offering an array of tetracyclic heteroaromatic products in good to excellent yields. Furthermore, the base can efficiently catalyze the second annulation step, yielding structurally unique thiophene-fused [1,6]naphthyridines in good yields.
View Article and Find Full Text PDFGrowth hormone and insulin like growth factor-1 plays an important role in the regulation of body composition and metabolism. Growth Hormone is released from the pituitary through a specific G-protein coupled receptor (GPCR) called growth hormone secretagogue receptor 1a expressed in the hypothalamus. Ghrelin is a peptide hormone released from the cells in the stomach, which stimulates appetite and food intake in mammals, regulates gut motility, gastric acid secretion, taste sensation, circadian rhythm, learning and memory, oxidative stress, autophagy, glucose metabolism etc.
View Article and Find Full Text PDFHerein, we present a Zn(II)-catalyzed (3 + 3) heteroannulation reaction between aromatic amines and 1,3-diynamides for the synthesis of amidoquinolines. A large number of aromatic amines are well tolerated, furnishing quinoline derivatives in up to excellent yield. Notably, various reactive functional groups have survived under the optimal reaction conditions, highlighting the mildness of the developed protocol.
View Article and Find Full Text PDFHerein, a catalytic synthetic transformation offering a series of -NH group-bearing aminoisoquinolines with moderate to good yields has been showcased. Interestingly, the nitrogen atom of the isoquinoline ring is coming from the reaction medium upon metal-assisted C≡N bond cleavage. Moreover, this (5+1) annulation reaction shows broad substrate variation.
View Article and Find Full Text PDFCascade or domino reactions serve as a powerful technique for the synthesis of complex organic scaffolds in one pot. Herein, a Cu(II)-catalyzed and silica gel-assisted multicomponent reaction (MCR) between bromoalkyne-tethered cyclohexadienones, amides, and water for the construction of hexahydrobenzofuran-3-carboxamide is developed. The reaction proceeds via a C-N coupling reaction followed by hydrative cyclization of ynamide intermediates.
View Article and Find Full Text PDFA one-pot copper-catalyzed [4 + 1] annulation reaction of primary amines with ynamide-derived buta-1,3-diynes for the synthesis of 2,5-diamido bearing -aryl/alkyl pyrroles in up to excellent yields has been showcased. A broad range of primary amines having highly reactive functional groups are well tolerated. Notably, sterically demanding aniline and primary aliphatic amines are excellent amine sources.
View Article and Find Full Text PDFChem Commun (Camb)
February 2022
Scaffolds having a 1-pyrrolo[3,2-]pyridine core show significant biological activity. Herein, we report a synergetic copper/zinc-catalyzed one-step annulation reaction of 2-amino (hetero)arylnitriles with ynamide-derived buta-1,3-diynes to deliver 1-pyrrolo[3,2-]quinoline-2,4-diamine derivatives in moderate to good yields. The annulation reaction follows a double cyclization pathway.
View Article and Find Full Text PDFObjective: To test efficacy, safety and tolerability of Umifenovir in non-severe COVID-19 adult patients.
Methods: We carried out randomized, double-blind, placebo-controlled, multicenter, phase III trials involving adult (18-75 years), non-severe COVID19 patients, randomized 1:1 on placebo or Umifenovir (800 mg BID, maximum 14 days) respectively along with standard-of-care. The primary endpoint for Asymptotic-mild patients was time to nasopharyngeal swab RT-PCR test negativity.
A Au(i)-catalyzed homo- and cross-annulation reaction of alkynyl carboxylic acids offering 3,6-disubstituted 4-hydroxy 2H-pyrones has been demonstrated. The reaction tolerates various substituted alkynyl carboxylic acids and moderate to good yields of α-pyrone scaffolds have been observed. Later, a gram-scale reaction of the acid and the total synthesis of the natural product pseudopyronine A have been carried out successfully.
View Article and Find Full Text PDFWe report an efficient synthesis of furopyrans through a gold(I)-catalyzed domino reaction. By starting from the same source and changing the solvent of the reaction, two classes of furopyrans are accessible. During this one-step process, which takes place in DMF, two bonds and two heterocycles are formed.
View Article and Find Full Text PDFWe report herein the synthesis of complex molecules containing furopyran cores through a gold(I)-catalyzed hetero-Diels-Alder cascade reaction. During this process, the diene and the dienophile are produced concomitantly by the action of a single catalyst from a single starting material. Moreover, six bonds, four heterocycles, and four controlled stereogenic centers are formed in a one-step operation.
View Article and Find Full Text PDFA novel synthetic route to benzo[f]dihydroisoquinolone through a p-TsOH promoted cascade cyclization of easily accessible diyne-tethered ynamides in the presence of a Au(I)-catalyst is described. This reaction unveils a broad substrate scope, constructing a wide range of benzo[f]dihydroisoquinolones in good yields. The diyne-tethered ynamides are synthesized from inexpensive o-iodoaniline through Sonogashira couplings and the Cu-mediated C-N bond formation.
View Article and Find Full Text PDFA base promoted reaction between N-protected propargyl amines and 3-bromopropiolate readily provides an array of novel stable alkyne-tethered ketene N,N-acetals in good yields. A wide range of structurally complex cyclobutene-fused azepine heterocycles are synthesized through the gold-catalyzed intramolecular cycloisomerization of ketene N,N-acetals for the first time. A plausible reaction pathway is deduced on the basis of the (1)H NMR studies.
View Article and Find Full Text PDFRegioselective hydration of the terminal halo-substituted propargyl carboxylate by gold(I) catalyst is reported. The mild catalytic conditions tolerate common acid-labile protecting groups, and a wide variety of α-acyloxy α'-halo ketones are efficiently synthesized within a short reaction time. The α-acyloxy α'-halo ketones are used for the synthesis of 2-aminothiazoles.
View Article and Find Full Text PDFA general atom-economical approach for the synthesis of α-acyloxy methyl ketone is demonstrated through regioselective hydration of a wide range of propargyl acetates. Readily available catalyst comprising of 1% Ph(3)PAuCl and 1% AgSbF(6) in dioxane-H(2)O efficiently hydrolyzes the terminal alkynes of the propargyl acetate in the absence of acid promoters at ambient temperature within a short time. Effective regioselective hydration is facilitated by the neighboring carbonyl group as demonstrated through (18)O-labeling study.
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