7686-79-5

Upstream product

• 21622-01-5 ethyl 3-cyclopentene-1-carboxylate 
• 62-53-3 aniline 
• 98-95-3 nitrobenzene 
• 7686-77-3 3-cyclopentene-1-carboxylic acid 
• 84646-68-4 Dimethyl 3-cyclopentene-1,1-dicarboxylate 
• 88326-51-6 Dimethyl 3-cyclopentene-1,1-dicarboxylate 
• 128535-00-2 3-Cyclopentencarbonsaeureanilid 
• 3744-80-7 cyclopent-3-ene-1-carboxylic acid chloride 

Relevant academic research and scientific papers

Chromium-catalyzed ligand-free amidation of esters with anilines

Amides are important structural motifs in pharmaceutical and agrochemical chemistry because of the intriguing biological active properties. We report here the amidation of commercially available esters with anilines that was promoted by low-cost and air-stable chromium(III) pre-catalyst combined with magnesium, providing access to amides. This reaction occurs without the use of external ligands in a simple operation. Mechanistic studies indicate that a reactive aminated Cr species responsible for the amidation can be considered, which may be formed by reaction of low-valent Cr with aniline followed by reduction with hydrogen evolution.

Photoredox-Catalyzed Difunctionalization of Unactivated Olefins for Synthesizing Lactam-Substituted gem-Difluoroalkenes

Herein, the synthesis of lactam-substituted gem-difluoroalkenes has been developed through a photoredox-catalyzed radical cascade reaction. This developed photoredox-catalyzed, Br?nsted base-assisted intramolecular 5-exo-trig cyclization/intermolecular radical addition/β-fluoride elimination reaction offers a simple method for producing lactam, carbamate, or urea-substituted gem-difluoroalkenes with good functional group tolerance and high yields.

Chromium-Catalyzed Activation of Acyl C-O Bonds with Magnesium for Amidation of Esters with Nitroarenes

Here, we report a chromium-catalyzed activation of acyl C-O bonds with magnesium for amidation of esters with nitroarenes. Low-cost chromium(III) chloride shows high reactivity in promoting amidation by using magnesium as reductant and chlorotrimethylsilane as additive. It provides a step-economic strategy to the synthesis of centrally important amide motifs using inexpensive and air-stable nitroarenes as amino sources.

Merging Photoredox PCET with Ni-Catalyzed Cross-Coupling: Cascade Amidoarylation of Unactivated Olefins

The integration of amidyl radicals with cross-coupling chemistry opens new avenues for reaction design. However, the lack of efficient methods for the generation of such radical species has prevented many such transformations from being brought to fruition. Herein, the amidoarylation of unactivated olefins by a cascade process from non-functionalized amides is reported by merging, for the first time, photoredox proton-coupled electron transfer (PCET) with nickel catalysis. This new technology grants access to an array of complex molecules containing a privileged pyrrolidinone core from alkenyl amides and aryl- and heteroaryl halides in the presence of a visible light photocatalyst and a nickel catalyst. Notably, the reaction is not restricted to amides—carbamates and ureas can also be used. Mechanistic studies, including hydrogen-bond affinity constants, cyclization rate measurements, quenching studies, and cyclic voltammetry, were central to comprehend the subtleties contributing to the integration of the two catalytic cycles. A rapid, highly diastereoselective amidoarylation of unactivated olefins was achieved to render medicinally privileged pyrrolidinone structures. Taking advantage of a photoredox proton-coupled electron transfer process, amidyl radicals were obtained from non-prefunctionalized N–H bonds under mild conditions, which were subsequently trapped by pendant olefins, delivering alkyl radicals for nickel-catalyzed cross-coupling. Mechanistic studies revealed the key balance between thermodynamically-driven radical generation and kinetically-driven cyclization, which led to expanding the scope toward urea and carbamate substrates. Rapid generation of molecular complexity and access to novel 3D chemical space is pivotal for successful and efficient drug discovery. Nickel/photoredox dual catalysis has arisen as an appealing strategy toward such a goal by rapidly introducing Csp3 centers under mild reaction conditions. By taking advantage of a native amide group, we achieved an amidoarylation reaction of unactivated olefins, rendering a series of medicinally privileged structures in a highly atom-economical way. The reaction takes advantage of a photoredox proton-coupled electron transfer event to cleave the strong amidyl N–H bond homolytically. Subsequent regiospecific 5-exo-trig cyclization generates an alkyl radical. High functional group tolerance was achieved with excellent diastereoselectivities owing to the reaction's mild nature. Mechanistic studies showed the intricate relationship between the base stoichiometry and the N–H donor, as well as the key balance between kinetic and thermodynamic factors.

Enantioselective desymmetrization via carbonyl-directed catalytic asymmetric hydroboration and Suzuki-Miyaura cross-coupling

The rhodium-catalyzed enantioselective desymmetrization of symmetric γ,δ-unsaturated amides via carbonyl-directed catalytic asymmetric hydroboration (directed CAHB) affords chiral secondary organoboronates with up to 98% ee. The chiral γ-borylated products undergo palladium-catalyzed Suzuki-Miyaura cross-coupling via the trifluoroborate salt with stereoretention.