29509-37-3

Upstream product

• 20657-21-0 3-acetoxycyclopent-1-ene 
• 13735-81-4 1-styrenyloxytrimethylsilane 
• 20599-27-3 1-bromopent-2-ene 
• 94-02-0 ethyl 3-oxo-3-phenylpropionate 
• 877070-40-1 2-(cyclopent-2-en-1-yl)-N-methoxy-N-methylacetamide 
• 108-86-1 bromobenzene 
• 13668-61-6 (cyclopent-2-eneyl)acetic acid 
• 933-03-9 2-(cyclopent-2-en-1-yl)acetyl chloride 
• 3212-60-0 cyclopent-2-enol 
• 536-74-3 phenylacetylene 

Relevant academic research and scientific papers

Cyclopentanone as a cation-stabilizing electron-pair donor in the calcium-catalyzed intermolecular carbohydroxylation of alkynes

Although they have been used as reactivity-controlling additives in cationic polymerizations for decades, Lewis basic electron pair donor (ED) compounds were never used for the stabilization of cationic intermediates in transformations of small molecules. As such an ED, cyclopentanone proved highly efficient for the stabilization of allyl and vinyl cations in combination with our calcium-based catalyst system. Therefore, the first general transition-metal-free intermolecular carbohydroxylation of alkynes with allyl and propargyl alcohols was realized.

Transition from π radicals to σ radicals: Substituent-tuned cyclization of hydrazonyl radicals

Hydrazonyl radicals are known for their π-electronic structures; however, their σ-electronic structures have not been reported as yet. Herein, we show that readily accessible β,γ- and γ,δ- unsaturated N-trichloroacetyl and N-trifluoroacetyl hydrazones can be conveniently converted into hydrazonyl σ radicals, which subsequently undergo 5-exo-trig radical cyclization at the N1 or N2 atom to form pyrazolines and azomethine imines, respectively. Time for a radical career change? Known for their π character, hydrazonyl radicals can be tuned to act as σ radicals with the spin density delocalized on both nitrogen atoms by attaching a trifluoroacetyl or trichloroacetyl group to the N 1 atom. The hydrazonyl σ radicals derived from the corresponding N-acyl-substituted β,γ- and γ,δ-unsaturated hydrazones underwent Ci-N1 and Ci-N2 bond-forming 5-exo-trig cyclization, respectively (see scheme).

Iminoxyl radical-promoted dichotomous cyclizations: Efficient oxyoximation and aminooximation of alkenes

A novel iminoxyl radical-involved metal-free approach to vicinal oxyoximation and aminooximation of unactivated alkenes is developed. This method utilizes the dichotomous reactivity of the iminoxyl radical to furnish a general difunctionalization on alkenes using simple tert-butyl nitrite (TBN) as the iminoxyl radical initiator as well the carbon radical trap. By using this protocol, oxime featured 4,5-dihydroisoxazoles and cyclic nitrones were facilely prepared from β,γ- and γ,δ-unsaturated ketoximes, respectively.

Highly efficient Narasaka-Heck cyclizations mediated by P(3,5-(CF 3)2C6H3)3: Facile access to N-heterobicyclic scaffolds

N-heterobicyclic scaffolds: Highly efficient palladium-catalyzed cyclizations of oxime esters with cyclic alkenes were used as a general entry to perhydroindole and related scaffolds. The chemistry is reliant upon the use of P(3,5-(CF3)2/

Oxime radical promoted dioxygenation, oxyamination, and diamination of alkenes: Synthesis of isoxazolines and cyclic nitrones

Up the tempo: The intramolecular addition of oxime radicals to C=C bonds was achieved by using DEAD and TEMPO to give 4,5-dihydroisoxazoles as a result of a C=O bond-forming, 5-exo-trig cyclization. γ,δ-Unsaturated ketoximes also reacted to afford cyclic nitrones through C-N bond formation. The reactions offer a metal-free approach for the vicinal difunctionalization of unactivated alkenes. Copyright

Molybdenum(II)- and tungsten(II)-catalyzed allylic substitution

The molybdenum(II) complexes Mo(CO)5(OTf)2 (7a), [Mo(CO)4Br2]2 (8a), their tungsten(II) congeners 7b and 8b, and bimetallic complex Mo(CO)3(MeCN)2(SnCl3)Cl (9a) have been found to catalyze the C-C bond-forming allylic substitution with silyl enol ethers derived from β-dicarbonyls (e.g., 16 + 30 → 46) or from simple ketones (e.g., 16 + 32 → 50), aldehydes, and esters as nucleophiles under mild conditions (room temperature, 1-2 h). Methanol, as a prototype oxygen nucleophile, reacts in a similar fashion (e.g., 16 + MeOH → 43). Mechanistic and stereochemical experiments are indicative of Lewis-acid catalysis rather than a metal template-controlled process.