Showing papers in "Organic Letters in 2004"
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TL;DR: The C3-symmetric derivative of polytriazolylamines, TBTA, was shown to be a powerful stabilizing ligand for copper(I), protecting it from oxidation and disproportionation, while enhancing its catalytic activity.
1,344 citations
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TL;DR: Copper(I)-catalyzed 1,3-dipolar cycloaddition reaction of nonfluorescent 3-azidocoumarins and terminal alkynes afforded intense fluorescent 1,2, 3-triazole products, which has potential in bioconjugation and bioimaging applications.
666 citations
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TL;DR: A microwave-assisted three-component reaction was used to prepare a series of 1,4-disubstituted-1,2,3-triazoles from corresponding alkyl halides, sodium azide, and alkynes, eliminating the need to handle organic azides.
517 citations
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TL;DR: An efficient palladium-catalyzed carbon-sulfur bond formation reaction of aryl bromides, triflates, and activated aryL chloride is developed that has shown tolerance to a wide variety of aries and alkyl thiols that can also be used as sulfide equivalents.
434 citations
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TL;DR: Well-defined color change in the visible region of the spectrum was observed upon addition of fluoride ion in DMSO/CH3CN solution of the receptors 1 and 2.
418 citations
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TL;DR: While monitoring the conversion via (1)H NMR spectroscopy, an intermediate 5-methylene-4,5-dihydrooxazole can be observed and accumulated up to 95%, being the first direct and catalytic preparative access to such alkylidene oxazolines.
372 citations
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TL;DR: A simple, high-yielding synthesis of 2,4,5-trisubstituted imidazoles from 1,2-diketones and aldehydes in the presence of NH(4)OAc is described.
368 citations
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TL;DR: It is found that the addition of 2,6-lutidine can suppress the side reactions and dramatically improve the yield of this classic reaction.
359 citations
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TL;DR: The aza-Henry reaction of imines with nitroalkanes was promoted by chiral thiourea with an N,N-dimethylamino group to give beta-nitroamines with good enantioselectivity.
326 citations
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TL;DR: The construction of chiral carbon centers via the first catalytic asymmetric alkynylation of prochiral CH2 groups was developed by using a copper-catalyzed double activation of sp3 and sp C-H bonds.
314 citations
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TL;DR: 1,4-Disubstituted 1,2,3-triazoles are obtained in excellent yields by a convenient one-pot procedure from a variety of readily available aromatic and aliphatic halides without isolation of potentially unstable organic azide intermediates.
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TL;DR: Two Colorimetric azobenzene based chemosensors 1 and 2 were designed for detection of transition-metal ions such as Cu(II) under physiological pH conditions and give rise to red-to-yellow color changes that are visible to the naked-eye and reversible upon addition of EDTA.
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TL;DR: It is demonstrated, for the first time, that the reaction of toluene and nitric acid in three different ionic liquids gives rise to three completely different products in high yield.
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TL;DR: In this article, the α,α-dialkylaldehydes with (E)-β-nitrostyrene provided the α-α-dynamic Michael products in up to 96% yield with up to 91% ee.
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TL;DR: A practical cross-coupling of amides with alkynyl bromides using catalytic CuSO(4).5H(2)O and 1,10-phenanthroline is described here and provides a general entry for syntheses of ynamides including various new sulfonyl and heteroaromatic amine substituted ynamide.
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TL;DR: An efficient method for the synthesis of diaryl ethers under particularly mild conditions is described, and inexpensive ligands were found to greatly accelerate the Ullmann-type coupling of aryl bromides or iodides with phenols.
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TL;DR: Mechanistic studies unambiguously support an electrophilic substitution pathway for palladium-catalyzed selective arylation and heteroarylation of indolizines at C-3.
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TL;DR: The preliminary experiment using (S)-proline methyl ester as a chiral source demonstrated that it could be developed to be a direct and highly diastereoselective method for construction of chiral propargylamines.
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TL;DR: Tris(acetylacetonato)iron(III) (Fe(acac)(3)) was found to be an efficient catalyst for the cross-coupling reaction between aryl Grignard reagents and alkyl halides possessing beta-hydrogens.
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TL;DR: An unexpected, interesting effect results from the introduction of a third C=C onto the ligand scaffold that results in high selectivity in Rh(I)-catalyzed conjugate addition reactions to substrates not previously examined with diene ligands.
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TL;DR: Novel octupolar fluorophores derived from the symmetrical functionalization of a triphenylamine core with strong acceptor peripheral groups via phenylene-ethynylene linkers have been synthesized and shown to exhibit high fluorescence quantum yields, very large TPA cross-sections in the red-NIR region, and suitable photostability.
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TL;DR: Much improved yields were obtained for a wide array of azides and alkynes in the regioselective synthesis of 1,5-disubstituted-1,2,3-triazoles via the addition of bromomagnesium acetylides to azides.
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TL;DR: A new, practical method by which N-substituted indoles may be selectively arylated in the C2-position with good yields, low catalyst loadings, and a high degree of functional group tolerance is presented.
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TL;DR: A method for the synthesis of vinyl sulfides using the soluble copper(I) catalyst [Cu(phen)(PPh3)2]NO3 is reported, which tolerates a wide variety of functional groups or substrates, is palladium-free, and does not require the use of expensive or air-sensitive additives.
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TL;DR: A new efficient method for the N-heterocyclization of primary amines with diols catalyzed by a CpIr complex was developed and a variety of five-, six-, and seven-membered cyclic amines were synthesized in good to excellent yields with the formation of only water as a byproduct.
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TL;DR: A series of crystalline acenedithiophenes with up to seven linearly fused rings and silylethynyl substituents are reported, designed to both improve solubility and enhance cofacial interactions in the solid.
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TL;DR: An aqueous biphasic reaction system enables the direct use of allylcohol in the Tsuji-Trost reaction without the help of any activating reagents for allyl alcohol.
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TL;DR: A new pseudorotaxane was designed and synthesized on the basis of viologen-CB7 binding interactions and its mode of interaction is different with longer chain viologens due to the favorable hydrophobic interactions between the terminal alkyl substituents and the inner cavity of the host.
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TL;DR: L-Proline-based small peptides have been developed as efficient catalysts for the asymmetric direct aldol reactions of hydroxyacetone with aldehydes and chiral 1,4-diols 7 were obtained in high yields and enantioselectivities in aqueous media.
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TL;DR: A preliminary mechanistic investigation of the rhodium-catalyzed arylation of a variety of heterocycles revealed the intermediacy of an isolable N-heterocyclic carbene complex.