A facile synthesis of pyridoquinazolinones has been accomplished via C(sp)-H functionalization and annulation of benzoic acids with 2-aminopyridines using Cu(OAc) as catalyst in DMSO. The reaction involves the formation of amides which on amination followed by -amidation afford a wide array of products under ligand/base-free conditions.
View Article and Find Full Text PDFA decarboxylative cyanomethylation of β-aryl/heteroaryl substituted α,β-unsaturated carboxylic acids has been accomplished via C(sp)-H activation of alkyl nitriles to afford diverse γ-ketonitriles by making use of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and -butyl hydroperoxide (TBHP).
View Article and Find Full Text PDFA practical C3 sulfenylation of indoles has been accomplished using arenediazonium tosylates and sodium metabisulfite, with a key role of iodine/DMF combination in the reaction. The method involves scarce use of sodium metabisulfite as a divalent sulfur source and offers an array of structurally diverse 3-arylthioindoles in high yields under operationally simple transition-metal-free and mild conditions.
View Article and Find Full Text PDFTwo new protocols leveraging electrochemical and hypervalent iodine-mediated synthesis of α-ketothioamides have been developed by using easily accessible and cost-effective Bunte salts and secondary amines. The methods are efficient, simple, and straightforward, and showcase the formation of C-N bonds across diverse substrates under ambient conditions.
View Article and Find Full Text PDFSite-selective C-H bond functionalization of arenes at the para position remains extremely challenging primarily due to its relative inaccessibility from the catalytic site. As a consequence, it is significantly restricted to limited molecular scaffolds. Herein, we report a method for the para-C-H borylation of aromatic aldimines and benzylamines using commercially available ligands under iridium catalysis.
View Article and Find Full Text PDFAn efficient visible-light-induced synthesis of vinyl sulfones has been accomplished via decarboxylative sulfonylation of cinnamic acids using sulfonylazides, -toluenesulfonylmethyl isocyanide, and β-keto sulfones as sulfonyl source, in the presence of inexpensive organic photocatalysts like rhodamine B and eosin Y. The reaction is facile, straightforward, and endowed with wide substrate scope and functional group tolerability.
View Article and Find Full Text PDFA new strategy for the synthesis of amides has been developed using sulfur-mediated decarboxylative coupling of cinnamic acids with amines via oxidative cleavage of the C═C bond.
View Article and Find Full Text PDFAn electrochemical strategy for the synthesis of unsymmetrical sulfoxides has been explored using Bunte salts and aryldiazonium tetrafluoroborates under constant current electrolysis at room temperature. In addition to being eco-safe and using mild conditions, the present protocol is free from the use of metal/oxidant, and is endowed with a broad substrate scope and good functional group tolerance.
View Article and Find Full Text PDFUnlabelled: Genetic diversity is the primary source of variability in any crop improvement program, and the diverse germplasm of any crop species represents an important genetic resource for gene or allele mining to meet future needs. Huge genetic and phenotypic diversity is present in the apple gene pool, even though, breeding programs have been mainly focused on a few traits of interests, which have resulted in the reduction of the diversity in the cultivated lines of apple. Therefore, the present study was carried out on 70 diverse apple genotypes with the objective of analyzing the genetic diversity and to identify the genetic loci associated with important fruit quality traits.
View Article and Find Full Text PDFA visible light-enabled synthesis of unsymmetrical ketones has been accomplished by the cross-coupling of α,β-unsaturated carboxylic acids and aryldiazonium salts embracing a synergistic eosin Y and Co(OAc)·4HO catalysis. The reaction involves decarboxylative aerobic CC bond cleavage, and is endowed with the creation of new C-C and C-O bonds with good substrate scope.
View Article and Find Full Text PDFUnlabelled: To unravel the plastid genome diversity among the cultivated groups of the pigeonpea germplasm, we characterized the SNP occurrence and distribution of 142 pigeonpea mini-core collections based on their reference-based assembly of the chloroplast genome. A total of 8921 SNPs were found, which were again filtered and finally 3871 non-synonymous SNPs were detected and used for diversity estimates. These 3871 SNPs were classified into 12 groups and were present in only 44 of the 125 genes, demonstrating the presence of a precise mechanism for maintaining the whole chloroplast genome throughout evolution.
View Article and Find Full Text PDFAn easy access to functionalized alkenes has been developed by the C-H functionalization of anilides with Morita-Baylis-Hillman (MBH) bromides in the presence of copper chloride, TBHP and acetic acid. Unsubstituted as well as /-substituted anilides exclusively give rise to the -allylated products, whereas -substitution brings about the formation of -allylated anilides.
View Article and Find Full Text PDFAn oxidative amination of 2-bromoacetophenones has been accomplished to provide α-ketoamides by using photoredox catalysis with air as oxidant. The reactants are readily accessible, and the method is endowed with broad substrate scope and good functional group tolerance. The practicality of the approach is also shown by a gram-scale reaction.
View Article and Find Full Text PDFA practical synthesis of new β-difluoromethoxy vinyl sulfones has been explored by -difluoromethylation of β-ketosulfones using the inexpensive and easily workable sodium chlorodifluoroacetate as a difluorocarbene precursor. The strategy is convenient and regioselective, and features an adequate substrate scope and functional group tolerance.
View Article and Find Full Text PDFA facile synthesis of α-carbonyl sulfones has been accomplished by the cross-coupling of α-aryl-α-diazoesters with sulfonyl hydrazides in the presence of CuI and DBU. The reaction employs inexpensive and bench stable sulfonyl hydrazides as a sulfonyl source, and facilitates the migratory insertion with α-aryl-α-diazoesters under mild reaction conditions.
View Article and Find Full Text PDFA facile and sustainable protocol for the thiolation of hydrazones with sodium sulfinates has been developed in the presence of CuBr and DBU in DMF to afford diverse benzylic thioethers. Control experiments reveal a radical pathway involving a thiyl radical as a key intermediate.
View Article and Find Full Text PDFAn efficient visible-light-induced synthesis of -oxiranes has been accomplished via decarboxylative stereospecific epoxidation of -cinnamic acids by aryldiazonium salts using CuCl, eosin Y, TBHP, and DBU. The reaction is facile, straightforward, and endowed with good functional group tolerability and a good substrate scope.
View Article and Find Full Text PDFAn oxidative amidation of 2-methylpyridines/2-methylbenzimidazole with amines using copper acetate and elemental sulfur in DMSO to afford various -(hetero)arylamides has been accomplished. Mechanistic studies reveal the intermediacy of -(pyridin-2-ylmethyl)aniline and confirm the role of DMSO as the oxygen source.
View Article and Find Full Text PDFA metal-free visible-light-induced trifluoromethylation of Bunte salts of α-bromoketones/alkyl bromide/benzyl bromides/functionalized allyl (Baylis-Hillman) bromides has been accomplished using Langlois' reagent in the presence of inexpensive eosin Y as a photocatalyst to form the privileged trifluoromethylthiolated synthons. The method is straightforward, operationally simple, and endowed with broad substrate scope and good functional group tolerance.
View Article and Find Full Text PDFSafflower (Carthamus tinctorius L.), an oilseed crop, is severely affected by Fusarium oxysporum f. sp.
View Article and Find Full Text PDFA facile photocatalyzed strategy for difunctionalization of styrenes in the presence of CS and amines providing β-keto dithiocarbamates has been developed. In the case of 4-nitrostyrene and 2-vinylpyridine, however, only 2-arylethylthiocarbamates are interestingly formed without the aid of photoredox catalysis/TBHP.
View Article and Find Full Text PDFMetal-free iodine-catalyzed regioselective thioallylation of indoles has been accomplished at room temperature using Bunte salts prepared from Baylis-Hillman bromides. The resulting multi-functional C3 thioallylated indoles exhibit ample structural diversity and good functional group tolerance.
View Article and Find Full Text PDFA concerted metallophotoredox catalysis has been realized for the efficient decarboxylative functionalization of α,β-unsaturated carboxylic acids with aryl iodides in the presence of perylene bisimide dye to afford 1,2-diketones.
View Article and Find Full Text PDFThe advent of multicomponent reactions in the synthesis of heterocycles and their ever burgeoning applications in drug development, materials chemistry, and catalysis, have attracted a great deal of current scientific interest. In particular, the metal-free multicomponent synthesis of six membered N-heterocycles has undergone intensive research over the last two decades offering an environmentally benevolent means contrary to traditional metal catalysed reactions. To the best of our knowledge, there exists no exclusive review on the metal-free multicomponent synthesis of six membered N-heterocyles, and hence the present report highlights the progress on metal-free multicomponent reactions with their advantages and mechanistic insights to access monocyclic six-membered N-heterocycles including pyridine, pyrimidine, pyrazine, triazine and their hydrogenated derivatives.
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