1345893-85-7

Upstream product

• 177944-16-0 (R)-N-(but-3-en-1-yl)-N-(α-methylbenzyl)amine 
• 3886-69-9 (R)-1-phenyl-ethyl-amine 
• 4185-69-7 1-(2,4-dinitrophenyl)-pyridinium chloride 
• 120343-60-4 (R)-1-phenylethylpyridinium chloride 
• 348608-12-8 2R-(+)-4,5-didehydro-N-[(R)-α-methylbenzyl]-2-propyl-piperidine 
• 1345893-78-8 tert-butyl but-3-enyl(R)-1-phenylethylcarbamate 
• 1345893-81-3 (R)-tert-butyl 5-oxoctyl(1-phenylethyl)carbamate 

Downstream Products

• 31608-18-1 (R)-(-)-coniine (S)-(+)-mandelic acid salt 

Relevant academic research and scientific papers

SYNTHETIC PROCESS

The present invention relates to a process for preparing substituted piperidine compounds and especially chiral substituted piperidine compounds. The process involves reacting a substituted pyridinium ion with an amine as defined herein, in the presence o

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

Diastereoselective access to nonracemic 2-cis-substituted and 2,6-cis-disubstituted piperidines

Access to nonracemic amino ketones via a hydrozirconation/transmetalation/ acylation sequence applied to Boc-protected 1-aminobut-3-enes is presented. This method was applied to the stereoselective synthesis of cyclic imines (or iminiums) which were diastereoselectively converted into 2-cis-substituted and 2,6-cis-disubstituted piperidines. The potential of this approach in the field of alkaloid synthesis was illustrated by the synthesis of (-)-coniine and (-)-indolizidine 209D. Furthermore, access to indolizidines bearing a quaternary center could also be envisioned through this strategy.