60272-70-0

Upstream product

• 1008-89-5 2-phenylpyridine 
• 78-84-2 isobutyraldehyde 
• 1539-32-8 4-isopropyl-2,6-dimethyl-1,4-dihydro-pyridine-3,5-dicarboxylic acid diethyl ester 
• 1131-33-5 2-phenylpyridin N-oxide 
• 100-47-0 benzonitrile 
• 2203-80-7 5-methylhex-1-yne 

Relevant academic research and scientific papers

Redox cycloisomerization approach to 1,2-dihydropyridines

The phosphine-catalyzed synthesis of 1,2-dihydropyridines via an alkyne isomerization/electrocyclization sequence is described. Propargylidenecarbamate substrates were prepared following a one-pot procedure between a terminal alkyne, a benzonitrile, and a chloroformate in the presence of trimethylaluminum. This methodology gives access to a diverse set of 2,6-disubstituted 1,2-dihydropyridines in high yield. The products can be easily converted into substituted piperidines or pyridines, and this methodology was applied to the synthesis of indolizidines.

Late-Stage C-H Alkylation of Heterocycles and 1,4-Quinones via Oxidative Homolysis of 1,4-Dihydropyridines

Under oxidative conditions, 1,4-dihydropyridines (DHPs) undergo a homolytic cleavage, forming exclusively a Csp3-centered radical that can engage in the C-H alkylation of heterocyclic bases and 1,4-quinones. DHPs are readily prepared from aldehydes, and considering that aldehydes normally require harsh reaction conditions to take part in such transformations, with mixtures of alkylated and acylated products often being obtained, this net decarbonylative alkylation approach becomes particularly useful. The present method takes place under mild reaction conditions and requires only persulfate as a stoichiometric oxidant, making the procedure suitable for the late-stage C-H alkylation of complex molecules. Notably, structurally complex pharmaceutical agents could be functionalized or prepared with this protocol, such as the antimalarial Atovaquone and antitheilerial Parvaquone, thus evidencing its applicability. Mechanistic studies revealed a likely radical chain process via the formation of a dearomatized intermediate, providing a deeper understanding of the factors governing the reactivity of these radical forebears.

Base-promoted, deborylative secondary alkylation of N-heteroaromatic: N -oxides with internal gem -bis[(pinacolato)boryl]alkanes: A facile derivatization of 2,2′-bipyridyl analogues

A base-promoted, secondary alkylation of N-heteroaromatic N-oxides using internal gem-bis[(pinacolato)boryl]alkanes as alkylation reagents is reported. The reaction exhibits a broad scope, providing deoxygenated secondary alkylated N-heteroaromatic compounds with high efficiency. The usefulness of the developed protocol is evidenced by the sequential direct alkylation of 2,2′-bipyridine-N-oxide.

Dioxygen-Mediated Decarbonylative C-H Alkylation of Heteroaromatic Bases with Aldehydes

An operationally simple and economical method for the direct alkylation of heteroaromatic bases employing readily available aldehydes as alkyl radical precursors and molecular oxygen as a reagent is presented. This simple transformation demonstrates a broad substrate scope with respect to aldehydes and nitrogen heterocycles, enabling the introduction of several medicinally important yet challenging alkyl moieties, such as ethyl, isopropyl, tert-butyl, and cyclohexyl to the different classes of heterocyclic bases in good to excellent yields. A simple method for the direct alkylation of heteroaromatic bases with aldehydes as inexpensive alkyl radical precursors and molecular oxygen as a reagent is presented. This transformation demonstrates a broad substrate scope with respect to aldehydes and nitrogen heterocycles, enabling the introduction of various alkyl moieties to heterocyclic bases (>40 examples) in good to excellent yields.