Showing papers in "Organic Letters in 2018"

TL;DR: A novel and efficient visible-light-induced C(sp2)-H/N-H cross-dehydrogenative coupling (CDC)-amination with both primary and secondary aliphatic amines at room temperature in air is developed.

TL;DR: An efficient synthesis of cyanoalkylated heteroarenes via iron-catalyzed direct C-H cyanoalksylation of heterOarenes has been developed andStructurally diverse cyanoALKyl motifs generated through C-C bond cleavage of cyclobutanone oxime esters have been introduced into quinoxalin-2(1H)-ones, flavone, benzothiazoles, and caffeine in good to excellent yields.

TL;DR: It is reported that Pd(PPh3)2Cl2 in combination with 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos) under irradiation of blue LEDs efficiently catalyzes a decarboxylative Heck reaction of vinyl arenes and vinyl heteroarenes with aliphatic N-(acyloxy)phthalimides at room temperature.

TL;DR: The development of a method for the Pd-catalyzed electrochemical acetoxylation of C-H bonds is described, developed and optimized with respect to the cell configuration, rate of oxidation, and chemistry at the counter electrode.

TL;DR: The synthetic utility of current method is demonstrated by the synthesis of PJ34 and Phenaglaydon and the in situ generated amidyl radicals undergo intramolecular C(sp2/sp3)-H aminations to give lactams with unprecedented regio- and chemoselectivities.

TL;DR: A practical, electrochemical method is developed for the direct dehydrogenative lactonization of C(sp2/sp3)-H bonds under external oxidant- and metal-free conditions, delivering diverse lactones, including coumarin derivatives with excellent regioselectivity.

TL;DR: A unified strategy for intermolecular remote C(sp3)-H and C-C vinylation of O-acyl oximes with vinyl boronic acids has been achieved and provides an efficient and versatile solution to the synthesis of γ-vinylation of ketones and nitriles.

TL;DR: The directly external oxidant-free oxytrifluoromethylation and aminotrifLUorometHylation of alkenes have been developed through the constant current electrolysis synergizing with a Lewis-acid catalysis protocol.

TL;DR: A general, Brønsted acid catalyzed method for the room temperature, nucleophilic ring opening of donor-acceptor cyclopropanes in fluorinated alcohol solvent, HFIP, is described and proved amenable to a wide range of nucleophiles.

TL;DR: A rhodium-catalyzed annulation between ethyl benzimidates and α- aroyl sulfur ylides was developed, affording a series of pyrano[4,3,2-ij]isoquinoline derivatives in moderate to good yields with good functional group compatibility.

TL;DR: An electrochemically driven, nickel-catalyzed reductive coupling of N-hydroxyphthalimide esters with aryl halides is reported and exhibits excellent substrate generality and functional group compatibility.

TL;DR: The efficient Pd-catalyzed Heck reaction of diverse tertiary alkyl halides with alkenes has been developed and it was shown that the end-game mechanism of this transformation may vary depending on the type of the substrates used.

TL;DR: One hexanuclear Cu(I) cluster of 4,6-dimethylpyrimidine-2-thiolate efficiently catalyzes the dehydrogenative cross-coupling of secondary and primary alcohols to α-alkylated ketones with high selectivity.

TL;DR: Synthesis of N-heterocycles, methylation of ketones, and one-pot double alkylation to bis-hetero aryl ketones using two different alcohols with a single catalyst broadens the scope of the catalytic protocol.

TL;DR: An enantioselective Minisci-type addition of α-amino acid-derived redox-active esters (RAEs) to isoquinolines has been developed, providing a range of valuable α-isoquinoline-substituted chiral secondary amines in high yields with good to excellent enantiOSElectivities.

TL;DR: A catalytic decarbonylative C-S coupling reaction that transforms thioesters into thioethers is described, and both Pd- and Ni-based catalysts are developed and applied to the construction of diaryl, aryl alkyl, and heterocycle-containing thio ethers.

TL;DR: A nickel-catalyzed cross-coupling of benzylic pyridinium salts with arylboronic acids was developed, which allows benzyl primary amines to be efficiently converted to di(hetero)arylmethanes.

TL;DR: It is reported that cis-TPE dicycles emit strong fluorescence, while the gem dicycle show almost no emission in solution, demonstrating that the free rotation restriction of the double bond at the excited state is the key factor for AIE effects.

TL;DR: An unprecedented N-heterocyclic carbene-catalyzed annulation of isatin-derived enals and o-hydroxyphenyl-substituted p-quinone methides as bifunctional reagents has been discovered.

TL;DR: This protocol provides expedient access to substituted N-heterocycles under mild and metal-free conditions and Mechanistic experiments indicate that this reaction proceeds through a visible-light-initiated radical chain propagation mechanism.

TL;DR: An iron-catalyzed redox-neutral, decarboxylative olefination of cycloketone oxime esters with α,β-unsaturated carboxylic acids has been developed, providing facile access to structurally diverse cyano-containing alkenes.

TL;DR: A chemodivergent copper-catalyzed ring opening of cycloketone oximes via radical-mediated C-C bond cleavage under redox-neutral conditions is described, allowing the divergent synthesis of γ- and δ-acyloxylation, alkoxylated, and hydroxylated nitriles while avoiding the use of toxic cyanide reagents.

TL;DR: A novel and practical method for the selenosulfonation of alkynes with the insertion of sulfur dioxide has been developed and a plausible radical mechanism is proposed to illustrate this reaction.

TL;DR: A metal-free photoredox C-H alkylation of heteroaromatics from readily available carboxylic acids using an organic photocatalyst and hypervalent iodine reagents under blue LED light is reported.

TL;DR: DFT calculations suggest molecular hydrogen acts not only as a reducing agent but also as an additive to displace thermodynamic equilibria.

TL;DR: A novel method to access 1,1-diarylalkanes from readily available, nonactivated alkyl bromides and aryl b Bromides via visible-light-driven nickel and iridium dual catalysis, wherein diisopropylamine is used as the terminal stoichiometric reductant.

TL;DR: Rh(III)-catalyzed cascade C-H activation of benzoylacetonitriles and annulation with sulfoxonium ylides was realized, leading to selective synthesis of naphthols, 2,3-dihydronaphtho[1,8- bc]pyrans, and naph fourthols.

TL;DR: The current method utilizes the radical acceptability of 2 H-indazoles, discovering an ambient temperature reaction to provide facile access to a diverse array of 3-acyl-2 H-Indazoles with three points of structural diversification in 25%-83% yields.

TL;DR: A method for the coupling of aryl chlorides and thiophenols using an air-stable nickel(0) catalyst is described and a variety of thiol coupling partners and, in certain cases, the use of Cs2CO3 are illustrated.

TL;DR: A selective oxy-difluoroalkylation of allylamines with carbon dioxide (CO2) via visible-light photoredox catalysis is reported, providing great potential for application in organic synthesis and pharmaceutical chemistry.