Modified Fry Cyanation of a Chiral Pyridinium Salt: Asymmetric Syntheses of (-)-Coniine and (-)-Solenopsin A
作者:Van Ha Vu、Laurie-Anne Jouanno、Adèle Cheignon、Thierry Roisnel、Vincent Dorcet、Sourisak Sinbandhit、Jean-Pierre Hurvois
DOI:10.1002/ejoc.201300595
日期:2013.8
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
Short Enantioselective Total Syntheses of the Piperidine Alkaloids (<i>S</i>)-Coniine and (2<i>R</i>,6<i>R</i>)-<i>trans</i>-Solenopsin A via Catalytic Asymmetric Imine Hydrosilylation
作者:Matthew T. Reding、Stephen L. Buchwald
DOI:10.1021/jo980808q
日期:1998.9.1
The enantioselectivesyntheses of (S)-coniine and (2R,6R)-trans-solenopsin A are reported. The key step in both syntheses is the catalytic asymmetric hydrosilylation of a cyclic imine.
The Role of the Alcohol and Carboxylic Acid in Directed Ruthenium-Catalyzed C(sp3)H α-Alkylation of Cyclic Amines
作者:Sheba D. Bergman、Thomas E. Storr、Hana Prokopcová、Karel Aelvoet、Gaston Diels、Lieven Meerpoel、Bert U. W. Maes
DOI:10.1002/chem.201201072
日期:2012.8.13
A general directed Ru‐catalyzedC(sp3)Hα‐alkylation protocol for piperidines (less‐reactive substrates than the corresponding five‐membered cyclicamines) 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
Synthesis of enantiomerically pure fire ant venom alkaloids: Solenopsins and isosolenopsins A, B and C
作者:H. M. T. Bandara Herath、N. P. Dhammika Nanayakkara
DOI:10.1002/jhet.5570450112
日期:2008.1
Concise and efficient methods for the synthesis of enantiomers of fireantvenomalkaloidssolenopsin and isosolenopsin A, B, and C are described. These syntheses are based on diastereoselective electrophilic substitution of enatiomerically-pure α-lithiated 2-alkylpiperidine.
Solenopsins A, B and C have been synthesized in enantiomericallypure forms from the corresponding anti-1,5-diols which have been obtained from glutaric anhydride by an asymmetric synthesis induced by chiral sulfoxides.