Selective hydrogenation of quinoline and its homologs, isoquinoline, and phenyl-substituted pyridines in the benzene ring

Vierhapper, Friedrich W.; Eliel, Ernest L.

doi:10.1021/jo00907a006

Cited by 81 publications

(22 citation statements)

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“…3/3,10-Dimethyl-trans-decahydroquinoline (18), 3%. No derivatives of 18 were prepared because of the extremely small amount of isolated material.…”

Section: Methodsmentioning

confidence: 99%

Conformational analysis. 33. Carbon-13 nuclear magnetic resonance spectra of saturated heterocycles. 5. cis-Decahydroquinolines

Vierhapper¹,

Eliel²

1977

J. Org. Chem.

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The 13C KMR spectra of cis-decahydroquinoline, its two epimeric 3-, 6-, and 8-methyl, as well as its 10-methyl, 3cu,10-, 3P,lCI-, and 8a,lO-dimethyl homologues and the corresponding N-methyl compounds were recorded. Configurational and conformational assignments have been made on the basis of 13C and lH NMR spectra. The parent, 10-methyl, 6P-methyl, and @-methyl compounds are conformationally heterogeneous; conformational equilibria were determined by low-temperature I3C NMR spectroscopy. Signals in the 13C spectra were assigned on the basis of those of the parent compounds3a-c with the help of parameters previously established2 in the trans-decahydroquinoline series. The previously reported2 upfield shift due, formally, to an antiperiplanar lone pair on nitrogen bearing alkyl [anti-:N(Me)-C-C] as well as the downfield shift caused by steric compression of syn-axial methyl groups were confirmed. Groups to which syn-axial substituents are attached are also shifted downfield. Shift parameters of the type introduced by Grant and c o -w o r k e r~~.~~~ are tabulated for the cis-decahydroquinoline series. The I3C spectra of A1~9-octahydroquinoline and several of its methyl homologues have been recorded. Conformational equilibria in variously substituted cis-decahydroquinolines are discussed.In a previous paper2 we have discussed the 13C NMR spectra of a number of methyl-substituted trans-decahydroquinolines. Here we report the spectra of 11 cis-decahydroquinolines, 1-11 (R = H), and of the corresponding Nmethyl homologues lm-1 l m (R = CH3). The spectra of the parent compounds 1 and l m have already been published by Booth and Griffiths3 and are included for completeness only; the remaining spectra are R, 1-11, R = H lm-llm, R = CH, 1, R,-R, = H 2, R , , R,, R,-R, = H ; R, = CH, (lO-CH,) 3, R , , R,-R, = H R, = CH, (3a-CH3) 4, R,-R, = H; R , = CH, (3P-CH3) 5, R,-R,, R,, R, = H ; R , = CH, (6U-CH,) 6, R,-R,, R,-R, = H ; R, = CH, (6P-CH3) 7, R,-R, = H ; R, = CH, (~cY-CH,) 8 , R,-R,, R, = H ; R, = CH, (8P-CH3) 9, R , , R , , R,-R, = H ; R, = R, = CH, (8a, 10-di-CH,) 10, R , , R,-R, = H ; R, = R, = CH, ( 3 a , 10-di-CH,) 11, R,, R,-R, = H ; R , = R, = CH, (3P, 10-di-CH,)In Table I are summarized all pertinent chemical shifts for compounds 1-11, in Table I1 those for lm-llm. The spectra were first recorded a t 30 "C but because a number of signals for the conformational1.y heterogeneous compounds 1,2,6, and 8 and their N-methyl analogues lm, 2m, 6m, and 8m were exchange-broadened at that temperature, their spectra were also recorded a t 55 "C or (in the case of 1) 65 "C. At these temperatures exchange was fast enough to lead to sharpening of all the signals. At low temperatures (-68 OC) the spectra of the eight conformatiionally heterogeneous compounds decoalesced into two sets of lines in each case (Tables I and 11) which could be assigned to the two contributing conformations. The spectra of the other 14 compounds did not change appreciably upon cooling (except for a slight temperature dependence of the chlemical shifts)...

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“…3/3,10-Dimethyl-trans-decahydroquinoline (18), 3%. No derivatives of 18 were prepared because of the extremely small amount of isolated material.…”

Section: Methodsmentioning

confidence: 99%

Conformational analysis. 33. Carbon-13 nuclear magnetic resonance spectra of saturated heterocycles. 5. cis-Decahydroquinolines

Vierhapper¹,

Eliel²

1977

J. Org. Chem.

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“…Thermal ellipsoids are shown at 50% probability levels, except for H-atoms which are drawn as small circles double bond to C-5 is blocked by the presence of two substituents at position 5 as in structure 12, no cyclisation was observed at C-4a and starting material was recovered. lt is proposed that this direct cyclisation is inhibited by an unfavourable steric interaction arising in structure 4 between an ortho proton on the aromatic ring and the axial proton at position 1 of the isoquinoline ring system (Fig. 3).…”

Section: Resultsmentioning

confidence: 99%

Synthesis of (±)-[4aα,4bβ,10bβ,12aβ]-9-halogeno-2-methyl-1,2,3,4,4a,4b,5,6,10b,11,12,12a-dodecahydronaphtho[2,1-ƒ]isoquinolines

Patrick¹

1995

J. Chem. Soc., Perkin Trans. 1

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“…Esterification of the commercially available 2‐quinolinecarboxylic acid ( 8 , Scheme ) gave 9 . Selective reduction of the quinoline system 9 under catalytic hydrogenation conditions11 afforded 5,6,7,8‐tetrahydro derivative 10 . Nucleophilic addition of an acetyl radical species12 para to the protonated pyridine nitrogen atom proceeded in nearly quantitative yield to generate the prochiral acetyl derivative 11 .…”

Section: Methodsmentioning

confidence: 99%

Stereocontrolled Synthesis of the Quinaldic Acid Macrocyclic System of Thiostrepton We thank Drs. D. H. Huang and G. Suizdak for NMR spectroscopic and mass spectrometric assistance, respectively, as well as Mike Sertic (University of California, San Diego) for experimental assistance. Financial support for this work was provided by The Skaggs Institute for Chemical Biology, the National Institutes of Health (USA), fellowships from The Skaggs Institute for Research (to M.Z. and F.Z.), and grants from Abbott

et al. 2002

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Selective hydrogenation of quinoline and its homologs, isoquinoline, and phenyl-substituted pyridines in the benzene ring

Cited by 81 publications

References 10 publications

Conformational analysis. 33. Carbon-13 nuclear magnetic resonance spectra of saturated heterocycles. 5. cis-Decahydroquinolines

Conformational analysis. 33. Carbon-13 nuclear magnetic resonance spectra of saturated heterocycles. 5. cis-Decahydroquinolines

Synthesis of (±)-[4aα,4bβ,10bβ,12aβ]-9-halogeno-2-methyl-1,2,3,4,4a,4b,5,6,10b,11,12,12a-dodecahydronaphtho[2,1-ƒ]isoquinolines

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