- Protecting-Group-Directed Regio- and Stereoselective Oxymercuration-Demercuration: Synthesis of Piperidine Alkaloids Containing 1,2- and 1,3-Amino Alcohol Units
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An efficient synthesis of naturally occurring 1,2- and 1,3-amino alcohol unit containing 2-substituted piperidine alkaloids and their analogues has been developed from l -pipecolinic acid. The protocol describes the regio- and stereoselective oxymercuration-demercuration of 2-alkenyl piperidines based on protecting groups to give piperidine alkaloids as a key step.
- Bugde, Sandesh T.,Volvoikar, Prajesh S.,Tilve, Santosh G.
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p. 1113 - 1122
(2017/12/06)
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- Henry-Nef reaction: A practical and versatile chiral pool route to 2-substituted pyrrolidine and piperidine alkaloids
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The paper describes the synergistic protocol developed by combinatorial Henry and Nef reaction for the synthesis of 2-substituted pyrrolidine and piperidine alkaloids containing 1,3-aminoketone and 1,3-amino alcohol units. The utility of the protocol is demonstrated by asymmetric synthesis of 12 natural products of which asymmetric synthesis of (-)-N-methylpelletierine is presented for the first time. The one-carbon homologation described also provides an alternate route for the synthesis of key intermediates homoprolinol and homopipecolinol used as synthetic precursors for several alkaloids and construction of β-amino acids from α-amino acids.
- Bhat, Chinmay,Tilve, Santosh G.
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p. 6129 - 6143
(2013/07/27)
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- A concise diastereoselective approach to (+)-dexoxadrol, (-)-epi-dexoxadrol, (-)-conhydrine and (+)-lentiginosine from (-)-pipecolinic acid
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A new diastereoselective pathway for the total synthesis of (+)-dexoxadrol, first asymmetric synthesis of (-)-epi-dexoxadrol and formal synthesis of conhydrine and (+)-lentiginosine is presented using commercially available (-)-pipecolinic acid. The key reactions utilized are Sharpless asymmetric dihydroxylation and Wittig reaction. The paper further describes the study of effect of protecting groups on dihydroxylation of a terminal olefin in piperidine ring system.
- Bhat, Chinmay,Tilve, Santosh G.
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p. 10876 - 10883
(2014/01/06)
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- Chemoenzymatic synthesis, structural study and biological activity of novel indolizidine and quinolizidine iminocyclitols
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The synthesis, conformational study and inhibitory properties of diverse indolizidine and quinolizidine iminocyclitols are described. The compounds were chemo-enzymatically synthesized by two-step aldol addition and reductive amination reactions. The aldol addition of dihydroxyacetone phosphate (DHAP) to N-Cbz-piperidine carbaldehyde derivatives catalyzed by l-rhamnulose 1-phosphate aldolase from Escherichia coli provides the key intermediates. The stereochemical outcome of both aldol addition and reductive amination depended upon the structure of the starting material and intermediates. The combination of both reactions furnished five indolizidine and six quinolizidine type iminocyclitols. A structural analysis by NMR and in silico density functional theory (DFT) calculations allowed us to determine the population of stereoisomers with the trans or cis ring fusion, as a consequence of the inversion of configuration of the bridgehead nitrogen. The trans fusion was by far the most stable, but for certain stereochemical configurations of the 3-hydroxymethyl and hydroxyl substituents both trans and cis fusion stereoisomers coexisted in different proportions. Some of the polyhydroxylated indolizidines and quinolizidines were shown to be moderate to good inhibitors against α-l-rhamnosidase from Penicillium decumbens. Indolizidines were found to be moderate inhibitors of the rat intestinal sucrase and of the exoglucosidase amyloglucosidase from Aspergillus niger. In spite of their activity against α-l-rhamnosidase, all the compounds were ineffective to inhibit the growth of the Mycobacterium tuberculosis, the causative agent of tuberculosis. The Royal Society of Chemistry 2012.
- Gómez, Livia,Garrabou, Xavier,Joglar, Jesús,Bujons, Jordi,Parella, Teodor,Vilaplana, Cristina,Cardona, Pere Joan,Clapés, Pere
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body text
p. 6309 - 6321
(2012/09/05)
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- An improved method of ring closing metathesis in the presence of basic amines: Application to the formal synthesis of (+)-lentiginosine and other piperidines and carbamino sugar analogs
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A generalized method for performing ring closing metathesis in the presence of basic amines has been established and successfully used in the formal synthesis of (+)-lentiginosine as well as some valuable intermediates for the synthesis of several other a
- Lahiri, Rima,Kokatla, Hari Prasad,Vankar, Yashwant D.
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supporting information; experimental part
p. 781 - 786
(2011/03/21)
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- Intramolecular Michael-type additions to vinyl bissulfoxides: Enantioselective synthesis of chiral aldehydes
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The diastereoselective auxiliary-based intramolecular Michael-type additions to alkylidene bissulfoxides derived from dithiane and dithiolane were investigated. Utilization of substrates bearing N- and O-nucleophilic functions led to the formation of the
- Gehring, Timo,Podlech, Joachim,Rothenberger, Alexander
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experimental part
p. 2476 - 2487
(2009/04/07)
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- Short syntheses of (S)-pipecolic acid, (R)-coniine, and (S)-δ-coniceine using biocatalytically-generated chiral building blocks
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The kinetic resolutions of both (±)-N-(benzyloxycarbonyl-2- (hydroxymethyl)piperidine [(±)-5] and (±)-N(tert-butoxycarbonyl)-2- (hydroxymethyl)piperidine [(±)-6] catalyzed by the enzyme acylase I from Aspergillus species (AA-I) afforded the chiral building blocks (S)-5 and (S)- 6, respectively; which were used for the syntheses of the title natural products and derivatives of (S)-pipecolic acid. The syntheses were short (2- 4 steps) and proceeded with satisfactory overall yield.
- Sanchez-Sancho, Francisco,Herradon, Bernardo
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p. 1951 - 1965
(2007/10/03)
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- Stereoselective synthesis of (+)-and (-)-lentiginosine
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Simple routes to (1R,2R,8aR)- and (1S,2S,8aS)-lentiginosine have been described, based on Sharpless asymmetric dihydroxylation, starting from (R)- and (S)-pipecolinic acids.
- Gurjar,Ghosh, Lakshmi,Syamala,Jayasree
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p. 8871 - 8872
(2007/10/02)
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- Construction of Chiral 2-functionalized Piperidine via Enzymatic Resolution and Palladium-catalyzed N-Alkylation
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The palladium-catalyzed cyclization of the optically active urethan , which was obtained by enzymatic resolution of the racemic alcohol (1), gave the piperidine 6.This reaction affords highly efficient intramolecular chirality transfer.Compound 6 was converted into (+)-coniine and 2-hydroxymethylpiperidine.
- Hirai, Yoshiro,Nagatsu, Mayumi
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