Chemoselective Carbon-Carbon Cross-CouplingviaPalladium-Catalyzed Copper-Mediated CS Cleavage of Disulfides

Oxidative Dehydrosulfurative Cross-Coupling of 3,4-Dihydropyrimidine-2-thiones with Alkynes for Access to 2-Alkynylpyrimidines

A reaction method is described for the one-step synthesis of 2-alkynylpyrimidines from 3,4-dihydropyrimidin-1H-2-thiones (DHPMs) via dehydrosulfurative Sonogashira cross-coupling with concomitant oxidative dehydrogenation using a Pd/Cu catalytic system. Together with the ready availability of DHPMs possessing various substituents at the C4-C6 positions, this transformation offers rapid and general access to diverse 2-alkynylpyrimidine derivatives.

Palygorskite-anchored Pd complexes catalyze the coupling reactions of pyrimidin-2-yl sulfonates

In this work, an anchored Pd complex (PGS–APTES–Pd(OAc)₂) was prepared via simple and green steps from the natural clay mineral palygorskite and was well characterized by XPS, XRD, IR, SEM, and EDX. This complex was further utilized as a fine catalyst for the C–C/C–N coupling reactions of pyrimidin-2-yl sulfonates. Subsequently, the cyclic utilization test indicated the high stability and sustainability of this PGS–APTES–Pd(OAc)₂ catalyst, and no activation was required in the recycling process, providing an applicable and reusable catalyst in organic synthesis.

PGS–APTES–Pd(OAc)₂ was prepared through simple and green steps from the natural clay mineral palygorskite. Obviously, the stability and reusability of PGS–APTES–Pd(OAc)₂ were superior to those of the PGS–Pd catalyst (prepared by the impregnation method) in recycling test.

Cesium carbonate-promoted synthesis of aryl methyl sulfides using S-methylisothiourea sulfate under transition-metal-free conditions

In the presence of cesium carbonate, an efficient synthesis of aryl methyl sulfides by the reactions of aryl halides with commercially available S-methylisothiourea sulfate is developed. This odourless and highly crystalline solid can be used as the substitute for malodorous methanethiol. The gram-scale reaction also proceeds smoothly without the use of column chromatography separation. Similarly, 2-(dimethylamino)ethylthio and cyclopropylmethylthio groups can be easily introduced into the aromatic rings from the corresponding S-[2-(dimethylamino)ethyl]isothiourea dihydrochloride and S-cyclopropylmethylisothiourea hydrobromide. The possible reaction mechanism is proposed. It is believed that this route to aryl alkyl sulfides is well competitive with currently known methods due to its wide substrate scope, excellent yields, easy operation and transition-metal-free conditions.

Highly mono-selective ortho-methylthiolation of benzamides via cobalt-catalyzed sp2 C–H activation

A highly mono-selective ortho-methylthiolation of benzamides was achieved via Co-catalyzed coupling of benzamides with DMSO.

Base-catalyzed thio-lactamization of 2-(1-arylvinyl)anilines with CS2 for the synthesis of quinoline-2-thiones

Quinoline-2-thiones were prepared through a base-catalyzed thio-lactamization of 2-(1-arylvinyl)anilines with CS₂.

Phellilane L, Sesquiterpene Metabolite of Phellinus linteus: Isolation, Structure Elucidation, and Asymmetric Total Synthesis

A new cyclopropane-containing sesquiterpenoid, phellilane L (1), was isolated from the medicinal mushroom Phellinus linteus ("Meshimakobu" in Japanese), a member of the Hymenochaetaceae family and a well-known fungus that is widely used in East Asia. The planar structure of 1 was determined on the basis of spectroscopic analysis. The authors achieved the first total synthesis of 1. Our protecting group-free synthesis features a highly stereoselective one-pot synthesis involving an intermolecular alkylation/cyclization/lactonization strategy for construction of the key cyclopropane-γ-lactone intermediate. Additionally, our synthesis determined the absolute configuration of phellilane L (1).

Synthesis of disulfides tethered pyrroles from β-ketothioamides via a bicyclization/ring-opening/oxidative coupling reaction

A DABCO-promoted three-component reaction of β-ketothioamides, arylglyoxals and 2-cyanoacetate to construct disulfides tethered pyrroles has been developed.

Copper-catalyzed decarboxylative methylthiolation of aromatic carboxylate salts with DMSO

A novel copper-catalyzed decarboxylative methylthiolation of arenecarboxylate salts has been realized using DMSO as the methylthiolation source.

Copper(i) chloride promoted Csp2–N cross-coupling of 1,2-di(pyrimidin-2-yl) disulfides with amines: an efficient approach to obtain C2-amino functionalized pyrimidines

The copper(i)-promoted cross-coupling of 1,2-di(pyrimidin-2-yl) disulfides with aromatic amines and aliphatic amines to deliver C–N coupling products in moderate to good yields is reported in this paper.

Efficient nickel-catalyzed phosphinylation of C–S bonds forming C–P bonds

The first nickel-catalyzed phosphinylation of C–S bonds forming C–P bonds is developed. The reaction can proceed readily with the simple Ni(cod)₂ at a loading down to 0.1 mol% at the 10 mmol scale. Various aryl sulfur compounds, i.e. sulfides, sulfoxides and sulfones all couple with P(O)–H compounds to produce the corresponding organophosphorus compounds, which provides an efficient new method for the construction of C–P bonds.

Direct C–H heteroarylation of azoles with 1,2-di(pyrimidin-2-yl)disulfides through C–S cleavage of disulfides

C–C bond construction via C–H bond functionalization of oxazoles/thiazoles and C–S bond cleavage of di(hetero)aryl disulfides are described.

(2-Chlorobenzoyloxy)copper(i) catalyzed C–S cross-coupling of di(hetero)aryl disulfides with aryl boronic acids under base-free conditions

(2-Chlorobenzoyloxy)copper(i) exhibited high activity towards the challenging C–S cross-coupling of di(hetero)aryl disulfides with aryl boric acids with good to excellent yields under base-free conditions.

Highly regioselective para-methylthiolation/bridging methylenation of arylamines promoted by NH4I

Aryl methyl thioethers and methylene-bridged arylamines were synthesized via highly regioselective para-methylthiolation/bridging methylenation of arylamines using DMSO as the methylthio or methylene source in the presence of NH₄I under metal-free conditions.

Palladium-catalyzed desulfurative Sonogashira cross-coupling reaction of 3-cyano assisted thioamide-type quinolone derivatives with alkynes

A Pd-catalyzed Cu-mediated desulfurative Sonogashira cross-coupling reaction of thioamide-type quinolone derivatives was proposed for the construction of C_sp²–C_sp bonds.

Selective reduction of nitro-compounds to primary amines by nickel-catalyzed hydrosilylative reduction

The tolerances of many functional groups, e.g. aryl-chloride, aryl-bromide, alkene, alkynyl, ester, ether, oxhydryl, carboxylic acid, cyano group, nitrine, carbonyl, acyl, thioether and some heterocycles, were studied with unprecedentedly high chemoselectivity.