28720-60-7

Upstream product

• 95018-40-9 6-Undecyl-2,3,4,5-tetrahydropyridine 
• 160549-81-5 N-Boc-2(R)-undecylpiperidine 
• 753497-02-8 Methyl 2-Methyl-6-(4-oxoundecyl)piperidine-1-carboxylate 
• 95018-42-1 2-Methyl-6-undecyl-2,3,4,5-tetrahydropyridine 
• 132410-16-3 1-(tert-butoxycarbonyl)-6-methyl-2-n-undecyl-1,2,3,4-tetrahydropyridine 
• 132410-14-1 1-(tert-butoxycarbonyl)-cis-2-methyl-6-n-undecylpiperidine 
• 35285-61-1 2-methyl-6-undecyl-3,4,5,6-tetrahydropyridine 
• 95448-61-6 N-methoxycarbonyl-6-aminohept-1-ene 
• 56606-79-2 dec-1-en-3-one 
• 112724-33-1 1-methoxycarbonyl-6-methyl-2-(1-undecynyl)-1,2-dihydropyridine 
• 112724-45-5 1-methoxycarbonyl-6-methyl-2-undecyl-1,2,3,4-tetrahydropyridine 
• 92599-59-2 1-undecynylmagnesium bromide 
• 109-06-8 α-picoline 
• 821-95-4 1-undecene 

Relevant academic research and scientific papers

Hydrogenation of Pyridines Using a Nitrogen-Modified Titania-Supported Cobalt Catalyst

Novel heterogeneous catalysts were prepared by impregnation of titania with a solution of cobalt acetate/melamine and subsequent pyrolysis. The resulting materials show an unusual nitrogen-modified titanium structure through partial implementation of nitrogen into the support. The optimal catalyst displayed good activity and selectivity for challenging pyridine hydrogenation under acid free conditions in water as solvent.

Stereoselective synthesis of 2,6-: Trans -4-oxopiperidines using an acid-mediated 6- endo-trig cyclisation

An acid-mediated 6-endo-trig cyclisation of amine-substituted enones has been developed for the stereoselective synthesis of trans-6-alkyl-2-methyl-4-oxopiperidines. Performed under conditions that prevent removal of the Boc-protecting group or acetal formation, the key cyclisation was found to generate cleanly the 4-oxopiperidine products in high overall yields from a wide range of alkyl substituted enones. The synthetic utility of the trans-6-alkyl-2-methyl-4-oxopiperidines formed from this process was demonstrated with the total synthesis of the quinolizidine alkaloid, (+)-myrtine and the piperidine alkaloid, (-)-solenopsin A.

Access to 2,6-disubstituted piperidines: Control of the diastereoselectivity, scope, and limitations. applications to the stereoselective synthesis of (-)-solenopsine A and alkaloid (+)-241D

Scope and limitations in the diastereoselective preparation of 2,6-cis or 2,6-trans disubstituted piperidines are described, through intramolecular reaction of chiral β′-carbamate-α,β-unsaturated ketone. This methodology has been applied to the total synthesis of a few well chosen examples, such as (-)-solenopsine A and alkaloid (+)-241D.

Removal of the pyridine directing group from α-substituted N-(pyridin-2-yl)piperidines obtained via directed Ru-catalyzed sp3 C-H functionalization

Two strategies, "hydrogenation-hydride reduction" and "quaternization-hydride reduction", are reported that make use of mild reaction conditions (room temperature) to efficiently remove the N-pyridin-2-yl directing group from a diverse set of C-2-substituted piperidines that were synthesized through directed Ru-catalyzed sp3 C-H functionalization. The deprotected products are obtained in moderate to good overall yields irrespective of the strategy followed, indicating that both methods are generally equally effective. Only in the case of 2,6-disubstituted piperidines, could the "quaternization-hydride reduction" strategy not be used. The "hydrogenation-hydride reduction" protocol was successfully applied to trans- and cis-2-methyl-N-(pyridin-2-yl)-6-undecylpiperidine in a short synthetic route toward (±)-solenopsin A (trans diastereoisomer) and (±)-isosolenopsin A (cis diastereoisomer). The absolute configuration of the enantiomers of these fire ant alkaloids could be determined via VCD spectroscopy.

Modified fry cyanation of a chiral pyridinium salt: Asymmetric syntheses of (-)-coniine and (-)-solenopsin A

The synthesis of chiral 2-cyano-Δ4-tetrahydropyridine 5 was carried out in 85 % yield through a modified two-step Fry reductive cyanation of pyridinium salt (+)-3c that used lithium triethylborohydride as the hydride donor. An alkylation-reduction sequence provided 2-alkyl-substituted tetrahydropyridines (+)-10a and (+)-10b in 72-75 % yield after chromatographic purification. This protocol has been applied to the asymmetric syntheses of piperidine alkaloids (-)-coniine and (-)-solenopsin A. The two-step reductive cyanation of chiral pyridinium salt (+)-3c afforded α-amino nitrile 5 in 85 % yield, which underwent an alkylation-reduction sequence followed by removal of the chiral moiety to yield the hemlock alkaloid (-)-coniine as its mandelate salt (>99:1 er). This reaction sequence was also used for the synthesis of the trans-2,6-disubstituted piperidine alkaloid (-)-solenopsin A. Copyright

Metal-free borane-catalyzed highly stereoselective hydrogenation of pyridines

A metal-free direct hydrogenation of pyridines was successfully realized by using homogeneous borane catalysts generated from alkenes and HB(C 6F5)2 via in situ hydroboration. The reaction affords a broad range of piperidines in high yields with excellent cis stereoselectivities.

An efficient synthesis of (±) solenopsin A

The efficient total synthesis of ( ± ) solenopsin A ( 9 ) was achieved in a series of eight steps starting from readily available N -Bn-N -Boc alanine derivative 1. Copyright by Walter de Gruyter.

Rapid configuration analysis of the solenopsins

A protocol for rapid access to the relative and absolute configurations of the solenopsins, the venom alkaloids of fire ants (Solenopsis spp.), was developed based on chiral capillary gas chromatography. The synthesis of racemic mixtures of 2-methyl-6-alkylpiperidines and the isolation of natural (2R,6R)- and (2R,6S)-2-methyl-6-undecylpiperidines allowed for the standardization of the chromatographic method. Application of this protocol revealed the previously unknown natural occurrence of four stereoisomers of 2-methyl-6-undecylpiperidine in venom samples from workers and gynes of Solenopsis saevissima.

The role of the alcohol and carboxylic acid in directed ruthenium-catalyzed C(sp3)-H α-alkylation of cyclic amines

A general directed Ru-catalyzed C(sp3)-H α-alkylation protocol for piperidines (less-reactive substrates than the corresponding five-membered cyclic amines) has been developed. The use of a hindered alcohol (2,4-dimethyl-3-pentanol) as the solvent and catalyst activator, and a catalytic amount of trans-1,2-cyclohexanedicarboxylic acid is necessary to achieve a high conversion to product. This protocol was used to effectively synthesize a number of 2-hexyl- and 2,6-dihexyl piperidines, as well as the alkaloid (±)-solenopsin A. Kinetic studies have revealed that the carboxylic acid additive has a significant effect on catalyst initiation, catalyst longevity, and reverses the reaction selectivity compared with the acid-free reaction (promotes alkylation versus competing alkene reduction). Acid makes the difference! A directed Ru-catalyzed C(sp3)-H α-alkylation protocol for cyclic amines has been developed (see scheme). Kinetic studies revealed that the carboxylic acid aids catalyst activation, increases catalyst longevity, and reverses the reaction selectivity. The alcohol selected as the solvent plays an active role in the catalysis. Copyright

Synthesis of enantiomerically pure fire ant venom alkaloids: Solenopsins and isosolenopsins A, B and C

(Chemical Equation Presented) Concise and efficient methods for the synthesis of enantiomers of fire ant venom alkaloids solenopsin and isosolenopsin A, B, and C are described. These syntheses are based on diastereoselective electrophilic substitution of enatiomerically-pure α-lithiated 2-alkylpiperidine.