NiH-catalyzed anti-Markovnikov hydroamidation of unactivated alkenes with 1,4,2-dioxazol-5-ones for the direct synthesis of N-alkyl amides.

The addition of a nitrogen-based functional group to alkenes via a direct catalytic method is an attractive way of synthesizing value-added amides. The regioselective hydroamidation of unactivated alkenes is considered one of the easiest ways to achieve this goal. Herein, we report the NiH-catalyzed anti-Markovnikov intermolecular hydroamidation of unactivated alkenes enabled by using 2,9-dibutylphenathroline (diBuphen) as the ligand.

Cu-Catalyzed Cross-Electrophilic Coupling of α-Diazoesters with -Benzoyl Hydroxylamines for the Synthesis of Unnatural -Alkyl α-Amino Acid Derivatives.

We describe a Cu-catalyzed cross-electrophilic coupling reaction for synthesizing α-amino acid derivatives from α-diazoesters with -benzoyl hydroxylamines with Cu(OAc) as the catalyst and polymethylhydrosilane (PMHS) as the hydride reagent. Excellent functional group compatibilities were demonstrated. With ethyl 2-diazo-3-oxobutanoate as the precursor, a Cu-acetoacetate complex has been characterized by ESI-MS analysis.

Transition Metal-Catalyzed Regioselective Direct C-H Amidation: Interplay between Inner- and Outer-Sphere Pathways for Nitrene Cross-Coupling Reactions.

Catalytic C-N bond cross-coupling reactions have been a subject of fundamental importance in synthetic organic and medicinal chemistry because amides and amines are ubiquitous motifs in natural products, functional materials, and pharmaceuticals. Since the pioneering works of Breslow and Mansuy on the metalloporphyrin-catalyzed direct hydrocarbon amidation using sulfonyliminoiodinane reagents, substantial development has been achieved toward practical and selective amination protocols. Notably, Du Bois's group developed the dirhodium(II,II) carboxylate catalytic system for direct C(sp)-H amidations via Rh-sulfonyl nitrene intermediates.

Thioether-Directed NiH-Catalyzed Remote γ-C(sp)-H Hydroamidation of Alkenes by 1,4,2-Dioxazol-5-ones.

A NiH-catalyzed thioether-directed cyclometalation strategy is developed to enable remote methylene C-H bond amidation of unactivated alkenes. Due to the preference for five-membered nickelacycle formation, the chain-walking isomerization initiated by the NiH insertion to an alkene can be terminated at the γ-methylene site remote from the alkene moiety. By employing 2,9-dibutyl-1,10-phenanthroline () as the ligand and dioxazolones as the reagent, the amidation occurs at the γ-C(sp)-H bonds to afford the amide products in up to 90% yield (>40 examples) with remarkable regioselectivity (up to 24:1 rr).

2,2-difluorovinyl benzoates for diverse synthesis of gem-difluoroenol ethers by Ni-catalyzed cross-coupling reactions.

gem-Difluoroalkene is a bioisostere of carbonyl group for improving bioavailability of drug candidates. Herein we develop structurally diverse 2,2-difluorovinyl benzoates (BzO-DFs) as versatile building blocks for modular synthesis of gem-difluoroenol ethers (44 examples) and gem-difluoroalkenes (2 examples) by Ni-catalyzed cross coupling reactions. Diverse BzO-DFs derivatives bearing sensitive functional groups (e.

Copper-Catalyzed Oxidative Reaction of β-Keto Sulfones with Alcohols via C-S Bond Cleavage: Reaction Development and Mechanism Study.

A Cu-catalyzed cascade oxidative radical process of β-keto sulfones with alcohols has been achieved by using oxygen as an oxidant. In this reaction, β-keto sulfones were converted into sulfinate esters under the oxidative conditions via cleavage of C-S bond. Experimental and computational studies demonstrate that a new pathway is involved in this reaction, which proceeds through the formation of the key four-coordinated Cu intermediate, O-O bond homolysis induced C-S bond cleavage and Cu-catalyzed esterification to form the final products.

Cu-Catalyzed Deoxygenative C2-Sulfonylation Reaction of Quinoline N-Oxides with Sodium Sulfinate.

An unexpected Cu-catalyzed deoxygenative C2-sulfonylation reaction of quinoline N-oxides in the presence of radical initiator K2S2O8 was developed that used sodium sulfinate as a sulfonyl coupling partner. The mechanism studies indicate that the reaction proceeds via Minisci-like radical coupling step to give sulfonylated quinoline with good chemical yields.

N-Iodosuccinimide-Initiated Spirocyclopropanation of Styrenes with 1,3-Dicarbonyl Compound for the Synthesis of Spirocyclopropanes.

Herein is reported an N-iodosuccinimide-initiated spirocyclopropanation reaction of styrenes with 1,3-dicarbonyl compounds in the presence of white LED light. The reaction proceeds via two C-H and two C-I bond cleavage event, along with two C-C bond formation event, and formation of quaternary centers. These reactions could be carried out at room temperature and tolerated a wide range of substrates, resulting in good to excellent chemical yields.

Cascade alkylarylation of substituted N-allylbenzamides for the construction of dihydroisoquinolin-1(2H)-ones and isoquinoline-1,3(2H,4H)-diones.

An oxidative reaction for the synthesis of 4-alkyl-substituted dihydroisoquinolin-1(2H)-ones with N-allylbenzamide derivatives as starting materials has been developed. The radical alkylarylation reaction proceeds through a sequence of alkylation and intramolecular cyclization. The substituent on the C-C double bond was found to play a key role for the progress of the reaction to give the expected products with good chemical yields.

Copper-Catalyzed Aerobic Oxidative Reaction of Sulfonyl Hydrazides with Alcohols: An Easy Access to Sulfinates.

A Cu-catalyzed aerobic oxidative reaction between sulfonyl hydrazides and alcohols has been developed. In this reaction, sulfonyl hydrazides act as the sulfinic acid precursors to react with alcohols, resulting in sulfinic esters with up to 72 % yield. This catalytic system tolerates a wide range of sulfonyl hydrazide substrates, and represents a new strategy for the transformation of readily available sulfonyl hydrazides.

The syntheses of α-ketoamides via(n)Bu4NI-catalyzed multiple sp(3)C-H bond oxidation of ethylarenes and sequential coupling with dialkylformamides.

The (n)Bu4NI-catalyzed sequential C-O and C-N bond formation via multiple sp(3)C-H bond activation of ethylarenes, using N,N-dialkylformamide as the amino source, provided α-ketoamides with moderate yields.

Syntheses of sulfides and selenides through direct oxidative functionalization of C(sp3)-H bond.

A new protocol for C-S and C-Se bond formation by the direct functionalization of the C(sp(3))-H bond of alkanes under metal-free conditions was developed. Using (t)BuOO(t)Bu as the oxidant, the reaction of disulfides or diselenides with alkanes gave sulfides or selenides in moderate to good yields. The method was very simple and atom-economical.

Palladium-catalyzed highly selective ortho-halogenation (I, Br, Cl) of arylnitriles via sp2 C-H bond activation using cyano as directing group.

A palladium-catalyzed ortho-halogenation (I, Br, Cl) of arylnitrile is described. The optimal reaction conditions were identified after examining various factors such as catalyst, additive, solvent, and reaction temperature. Using cyano as the directing group, the halogenation reaction gave good to excellent yields.