We present herein the first visible-light-driven hydrocarboxylation as well carbocarboxylation of alkynes using CO2 via an iridium/cobalt dual catalysis. Such transformations provide access to various pharmaceutically important heterocycles in a one-pot procedure from readily available alkynes. Coumarins, 2-quinolones, and 2-benzoxepinones were directly accessed through alkyne hydrocarboxylation/alkene isomerization/cyclization sequence which Ir photocatalyst serves role promote...

Rose Bengal, an organic dye, was used as a visible light photocatalyst to investigate novel α-oxyamination reactions between 1,3-dicarbonyl compounds and free radical (TEMPO). Compounds that are difficult obtain such quaternary fluorinated were synthesized using this method. This photocatalytic reaction can also be performed in water.

An organocatalytic [3 + 2]-annulation between isatin-derived Morita–Baylis–Hillman adducts and cyclic sulfonimines has been developed in high yields with excellent enantio- diastereoselectivities via an allylic nitrogen-ylide intermediate. The reaction provides access to heavily substituted aza-spirooxindole derivatives, which also contain ring fused sultams.

An enantioselective [3+2] annulation of Morita–Baylis–Hillman carbonates with trifluoropyruvate catalyzed by modified cinchona alkaloids was developed in good to excellent yields diastereo- and enantioselectivities.

Abstract An enantioselective [3+2] cycloaddition of vinyl cyclopropane derived from 1,3‐indanedione with nitroalkenes catalyzed by palladium(0) a chiral bis( tert ‐amine) ligand was developed in high yields good diastereoselectivities and excellent enantioselectivities. The resulting ‐amine)–palladium complex proved to be highly efficient catalyst for this cycloaddition.

A direct intermolecular olefination of sp(3) C-H bond between 2-oxindoles and simple alkenes via a Cross-Dehydrogenative Coupling (CDC) strategy has been developed. In the absence additional base, moderate to excellent yields have obtained by using catalytic amount iodine with atmospheric oxygen as reoxidant. Based on observation radical capture experiment, transformation is proposed proceed process.

A methyl group can have a profound impact on the pharmacological properties of organic molecules. Hence, developing methylation methods and methylating reagents is essential in medicinal chemistry. We report palladium-catalyzed dimethylation reaction ortho-substituted iodoarenes using dimethyl carbonate as source. In presence K2CO3 base, are dimethylated at ipso- meta-positions iodo group, which represents novel strategy for meta-C–H methylation. With KOAc subsequent oxidative...

Abstract An efficient synthesis of oxacycles and azacycles was developed using a Brønsted base‐catalyzed tandem alkyne isomerization–Michael reaction sequence. Functionalized 2‐alkylidenetetrahydrofurans were prepared by an intramolecular oxy‐Michael on allene that generated in situ from alkynoate. The aza‐Michael version alkynylamines, alkynylamides alkynyl carbamates led to piperidines, lactams oxazolidinones, respectively. enantioselective this resulted axially chiral lactam with high...

Herein, we report a practical example of salicylaldehyde-based cobalt-catalyzed C−H deuteriomethoxylation benzamides using deuterated methanol, facilitated by 8-aminoquinoline as directing group. The cobalt catalyst is user-friendly, and the reaction exhibits broad functional group tolerance, accommodating benzene, heterocycles, naphthalene rings. synthetic utility this methodology was demonstrated through gram-scale subsequent removal to yield deuteriomethoxylated benzoic acid. Preliminary...

Background: Gene transfer using a nanoparticle vector is promising new approach for the safe delivery of therapeutic genes in human disease. The Tat peptide-decorated gelatin-siloxane (Tat-GS) has been demonstrated to be biocompatible as vector, and have enhanced gene transfection efficiency compared with commercial reagent. This study investigated whether intracisternal administration Tat-GS nanoparticles carrying calcitonin gene-related peptide (CGRP) can attenuate cerebral vasospasm...

The first Lewis acid-catalyzed intramolecular interrupted Nazarov cyclization of 1,4-pentadien-3-ols is described. Using FeBr3 as the catalyst, a series new substituted cyclopenta[b]indoles was prepared-through sequence cyclization, nucleophilic amination, and isomerization-with good yields high diastereo- regioselectivities. A similar catalytic process also developed for synthesis structurally interesting spiro[indene-1,4'-quinoline]s.

A novel textile-supported nanosilver (TsNS) catalyst was prepared and applied in nitroaromatic reduction with excellent activity, stability recyclability.

Abstract A simple and practical strategy for the preparation of 1,2‐dithiole‐3‐thiones via copper‐catalyzed defluorinative thioannulation trifluoropropynes has been developed using elemental sulfur as sole source. This reaction displays a wide substrate scope high functional group tolerance to afford corresponding S‐heterocycles in moderate good yields features efficient construction multiple C−S bonds through C−F bond cleavage CF 3 groups. magnified image

A copper-catalyzed isothiocyanation of amines with sodium bromodifluoroacetate and sulfur in the absence organophosphine has been established. This approach represents a simple efficient one-pot synthesis isothiocyanates, features excellent functional group tolerance use cheap, safe odorless source. Moreover, this process could directly provide isothiocyanate analogous bioactive molecules, thiocarbonyl-containing pesticides facile construction benzoxazole benzimidazole frames.

Since Hydrogen Sulfide (H2S) was recognized as a gas transmitter, its detection and quantification have become hot research topic among chemists biologists. In this area, fluorescent probes shown great advantages: fast strong response, low limit easy manipulation. Here we developed new probe that detected H2S selectively various bioactive inorganic salts. This based on the core structure of fluorescein reacted with through azide-reduction. Great linearity achieved correlating fluorescence...

Hydroisoquinoline derivatives were prepared in moderate to good enantioselectivities via a bicyclic guanidine-catalyzed tandem isomerization intramolecular-Diels-Alder (IMDA) reaction of alkynes. With this synthetic method, the first enantioselective synthesis (+)-alpha-yohimbine was completed 9 steps from IMDA products.

An efficient cooperative biscinchona alkaloid and Lewis acid catalytic system was developed in the enantioselective α-alkylation of 2-oxindoles with (3-indolyl)(phenyl)methanols to provide (2-oxindole)-linker-indole derivatives good yields (70–83%) high enantioselectivities (81%–92%).

Inter- and intramolecular titanium-mediated cyclopropanation reactions of vinylogous esters are reported. Comparison between the Kulinkovich provides mechanistic insight regarding reaction variables such as temperature, solvents, a Lewis acid additive.

Abstract A direct enantioselective reaction of cyclopent‐2‐enone‐derived Morita–Baylis–Hillman alcohols with 4‐hydroxycoumarins has been developed under the catalysis a chiral primary amine derived from cinchonine in combination Brønsted acid. The provides pyranocoumarin products three vicinal carbon centers highly regio‐, diastereo‐ and enantioselectivities through tandem allylic alkylation/intramolecular oxa‐Michael addition. magnified image

A Pd(ii)-catalyzed intermolecular C-H silylation reaction initiated by aminopalladation has been developed. The bonds were activated an alkyl Pd(ii) species generated through and then disilylated with hexamethyldisilane to form indolines as the final products. provides a new method for introduction of silyl groups into complex organic molecules.

A highly efficient palladium-catalyzed cascade annulation of 2-vinylbenzaldehydes with indoles has been achieved to afford 6-(3-indolyl)benzo[b]carbazoles under mild conditions in good yield and excellent regioselectivity. Mechanistic investigations reveal that the reaction proceeds via double addition indoles, unexpected intramolecular 1,4-aryl 1,2-hydrogen migrations, oxidative aromatization.

Abstract A silver‐catalyzed Minisci‐type reaction is reported here. Alkylation of electron‐deficient N‐heterocycles achieved in aqueous solution through decarboxylative cross‐coupling aliphatic acids and N‐heteroarenes open air without external Brønsted acid. Selectfluor used as a mild oxidant. Different substituents on heterocycles are tolerated. Primary secondary alkyl could be introduced efficiently into the heteroarenes.