10047-06-0Relevant articles and documents
NHC-stabilised Rh nanoparticles: Surface study and application in the catalytic hydrogenation of aromatic substrates
Martinez-Espinar, Francisco,Blondeau, Pascal,Nolis, Pau,Chaudret, Bruno,Claver, Carmen,Castillón, Sergio,Godard, Cyril
, p. 113 - 127 (2017)
New Rh-NPs stabilised by N-Heterocyclic Carbenes (NHC) were synthesized by decomposition of [Rh(η3-C3H5)3] under H2 atmosphere and fully characterized. Surface studies by FT-IR and NMR spectroscopy employing isotopically labelled ligands were also performed. The Rh0.2 NPs are active catalysts in the reduction of various aromatic substrates. In the reduction of phenol, high selectivities to cyclohexanone or cyclohexanol were obtained depending on the reaction conditions. However, this catalytic system exhibited much lower activity in the hydrogenation of substituted phenols. Pyridine was easily hydrogenated under mild conditions and interestingly, the hydrogenation of 4-methyl and 4-trifluoromethylpyridine resulted slower than that of 2-methylpyridine. The hydrogenation of 1-(pyridin-2-yl)propan-2-one provided the β-enaminone 13a in high yield as a consequence of the partial reduction of the pyridine ring followed by isomerization. Quinoline could be either partially hydrogenated to 1,2,3,4-tetrahydroquinoline or fully reduced to decahydroquinoline by adjusting the reaction conditions.
Proline catalyzed, one-pot three component Mannich reaction and sequential cyclization toward the synthesis of 2-substituted piperidine and pyrrolidine alkaloids
Chacko, Shibin,Ramapanicker, Ramesh
, p. 2023 - 2026 (2015/03/18)
Abstract A very effective one-pot three component reaction of 4-bromobutanal or 5-bromopentanal, acetone, and p-anisidine catalyzed by proline is reported. A three component Mannich reaction followed by cyclization leading to the synthesis of 2-substituted pyrrolidine and piperidine derivatives through simultaneous formation of two C-N and one C-C bond is reported. The usefulness of the reaction is demonstrated by the synthesis of (±)coniine, (±)pelletrine, (±)sedridine, and (±)allosedridine.
Stereocontrol in N-directed hydroboration: Synthesis of amino alcohols related to the piperidine alkaloids
Wang, Guoqiang,Vedejs, Edwin
supporting information; experimental part, p. 1059 - 1061 (2009/08/15)
Treatment of 2-(2'-alkenyl)-piperidine boranes with iodine or triflic acid induces internal hydroboration with high regiocontrol, even with a terminal alkene (R H). Good stereocontrol is possible for the N-benzyl substrates. Comparisons with acyclic model
DIASTEREOSELECTIVE INTRAMOLECULAR DIELS-ALDER RECTION OF N-ALKOXYCARBONYL-1-AZA-1,3-BUTADIENES AND A TOTAL SYNTHESIS OF THE PIPERIDINE ALKALOID, (+/-)-SEDRIDINE
Uyehara, Tadao,Chiba, Naoki,Suzuki, Ichiro,Yamamoto, Yoshinori
, p. 4371 - 4374 (2007/10/02)
Total synthesis of (+/-)-sedridine, the piperidine alkaloid, was accomplished on the basis of diastereoselective intramolecular Diels-Alder reaction of the ψ',ω'-unsaturated N-alkoxycarbonyl-1-aza-1,3-butadiene generated in situ from N-trimethylsilyl-1-az
The Regiochemistry and Stereochemistry of 1,3-Dipolar Cycloaddition of a Cyclic Nitrone
Ali, Sk. Asrof,Wazeer, Mohammed I. M.
, p. 597 - 606 (2007/10/02)
A study of the regiochemical and stereochemical behaviour of the 1,3-dipolar cycloaddition of a series of alkenes with 2,3,4,5-tetrahydropyridine 1-oxide has been carried out.The high degree of both regiochemical and stereochemical control observed in these reactions has been explained in terms of maximum overlap of frontier orbitals, repulsive steric encumbrance, and attractive secondary orbital interaction in the transition state.Most monosubstituted and 1,1-disubstituted alkenes gave 2-substituted cycloadducts.As the electron affinity of the monosubstituted alkene increases, an increasing tendency towards formation of the regioisomeric 3-substituted cycloadduct is encountered. 1,2-Disubstituted alkenes undergo cycloadditions to afford cycloadducts with electron-withdrawing substituents always in the C-3 position of the cycloadducts.Significant secondary orbital interaction is observed with the non-conjugated hydroxymethyl substituent.