97691-21-9

Upstream product

• 14627-81-7 di-tert-butylmagnesium 
• 1131-61-9 4-Phenylpyridine 1-oxide 
• 3282-30-2 pivaloyl chloride 
• 558-17-8 tert-Butyl iodide 
• 104-55-2 3-phenyl-propenal 
• 939-23-1 p-phenylpyridine 
• 38442-51-2 tert-butylmercury chloride 

Relevant academic research and scientific papers

Radical chain monoalkylation of pyridines

The monoalkylation of N-methoxypyridinium salts with alkyl radicals generated from alkenes (via hydroboration with catecholborane), alkyl iodides (via iodine atom transfer) and xanthates is reported. The reaction proceeds under neutral conditions since no acid is needed to activate the heterocycle and no external oxidant is required. A rate constant for the addition of a primary radical to N-methoxylepidinium >107 M-1 s-1 was experimentally determined. This rate constant is more than one order of magnitude larger than the one measured for the addition of primary alkyl radicals to protonated lepidine demonstrating the remarkable reactivity of methoxypyridinium salts towards radicals. The reaction has been used for the preparation of unique pyridinylated terpenoids and was extended to a three-component carbopyridinylation of electron-rich alkenes including enol esters, enol ethers and enamides.

Visible Light-Mediated Decarboxylative Alkylation of Pharmaceutically Relevant Heterocycles

A net redox-neutral method for the decarboxylative alkylation of heteroarenes using photoredox catalysis is reported. Additionally, this method features the use of simple, commercially available carboxylic acid derivatives as alkylating agents, enabling the facile alkylation of a variety of biologically relevant heterocyclic scaffolds under mild conditions.

Modular pyridine synthesis from oximes and enals through synergistic copper/iminium catalysis

We describe here a [3+3]-type condensation reaction of O-acetyl ketoximes and α,β-unsaturated aldehydes that is synergistically catalyzed by a copper(I) salt and a secondary ammonium salt (or amine). This redox-neutral reaction allows modular synthesis of a variety of substituted pyridines under mild conditions with tolerance of a broad range of functional groups. The reaction is driven by a merger of iminium catalysis and redox activity of the copper catalyst, which would initially reduce the oxime N-O bond to generate a nucleophilic copper(II) enamide and later oxidize a dihydropyridine intermediate to the pyridine product.

Direct synthesis of 4,4-disubstituted N-silyl-1,4-dihydropyridines

An unprecedented method for the preparation of 4,4-disubstituted 1,4-dihydropyridines is presented. It is based on the trapping reaction of 4-substitued N-silylpyridinium ions. When performed with dialkylmagnesium reagents, such as iPr2Mg, silyl protected 4,4-disubstituted 1,4-dihydropyridines were obtained in up to quantitative yields. High 1,4-selectivity was found for sterically demanding nucleophiles, whereas small nucleophiles (Me2Mg) tend to yield 1,2-addition-products. Grignard, dialkylzinc and organocopper reagents were found to give either no addition products or less favorable results. Reduction of the obtained 1,4-dihydropyridine with NaCNBH3 in the presence of HCl, followed by treatment with tert-butyl dicarbonate provided the corresponding N-Boc protected piperidines with high yields.

Alkylation of Pyridine in Free Radical Chain Reactions Utilizing Alkylmercurials

Pyridines or N,N,N',N'-tetramethyl-p-phenylenediamine will undergo a photostimulated free radical chain reaction with alkylmercury halides or carboxylates, yielding ring alkylated substitution products.Alkene mercuration products (R1CH(Y)CH(R2)HgX with Y=HO, RO, CH3CONH; X=Cl, CH3CO2, CF3CO2) can be used without isolation for the alkylation reaction