| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1345949 | Tetrahedron: Asymmetry | 2014 | 8 Pages |
A library of 1,3-difunctionalized pinane derivatives were synthesized and applied as chiral catalysts in the addition of diethylzinc to benzaldehyde. 1,3-Aminoalcohol 6a was prepared from (−)-nopinone 2 via stereoselective Mannich condensation and reduction of the resulting β-amino ketone 4. The key aminoalcohol 6a was transformed into primary, secondary and tertiary substituted aminoalcohols in order to study the effect of the substituent on catalytic activity. Starting from (−)-nopinone, cis- and trans-β-hydroxy esters 15 and 16 were prepared in a two-step stereoselective synthesis. Reduction of the hydroxy esters resulted in pinane-based 1,3-diols, while hydrolysis of the esters, followed by DCC-mediated amidation and subsequent reduction, led to cis- and trans-N-benzyl-1,3-aminoalcohols 8 and 23. trans-N-Benzyl-1,3-aminoalcohol 8 was also prepared by selective mono-debenzylation of 6a via a continuous-flow process in an H-Cube® system. The resulting aminoalcohols and diols were applied as chiral catalysts in the reaction of diethylzinc and benzaldehyde.
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(1R,3R,5R)-3-Dibenzylaminomethyl-6,6-dimethylbicyclo[3.1.1]heptan-2-oneC24H29NO[α]D20 = +118 (c 0.177, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,3R,5R)
(1R,3R,5R)-3-{[N-Benzyl-N-((R)-1-phenylethyl)amino]methyl}-6,6-dimethylbicyclo[3.1.1]heptan-2-oneC25H31NO[α]D20 = +89 (c 0.18, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,3R,5R,1R′)
(1R,2S,3R,5R)-3-Dibenzylaminomethyl-6,6-dimethylbicyclo[3.1.1]heptan-2-olC24H31NO[α]D20 = +39 (c 0.25, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3R,5R)
(1R,2S,3R,5R)-3-Aminomethyl-6,6-dimethylbicyclo[3.1.1]heptan-2-olC10H19NO[α]D20 = +39 (c 0.25, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3R,5R)
(1R,2S,3R,5R)-3-Benzylaminomethyl-6,6-dimethylbicyclo[3.1.1]heptan-2-olC17H25NO[α]D20 = +40 (c 0.24, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3R,5R)
(1R,2S,3R,5R)-3-Isopropylaminomethyl-6,6-dimethylbicyclo[3.1.1]heptan-2-olC13H25NO[α]D20 = +104 (c 0.25, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3R,5R)
(1R,2S,3R,5R)-3-(2-Hydroxybenzyl aminomethyl)-6,6-dimethylbicyclo[3.1.1]heptan-2-olC17H25NO2[α]D20 = +66 (c 0.25, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3R,5R)
(1R,2S,3R,5R)-3-(N-Benzyl-N-methylaminomethyl)-6,6-dimethylbicyclo[3.1.1]heptan-2-olC18H27NO[α]D20 = +23 (c 0.25, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3R,5R)
(1R,2S,3R,5R)-3-[(2H-Benz[e][1,3]oxazin-3(4H)-yl)methyl]-6,6-dimethylbicyclo[3.1.1]heptan-2-olC18H25NO2[α]D20 = +58 (c 0.26, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3R,5R)
N,N-Dibenzyl-1-((1R,2S,3R,5R)-2-benzyloxy-6,6-dimethylbicyclo[3.1.1]heptan-3-yl)methanamineC30H34NO[α]D20 = +171 (c 0.255, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3R,5R)
(1R,2S,3R,5R)-Methyl 2-hydroxy-6,6-dimethylbicyclo[3.1.1]heptane-3-carboxylateC11H18O3[α]D20 = −10 (c 0.24, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3R,5R)
(1R,2S,3S,5R)-Methyl 2-hydroxy-6,6-dimethylbicyclo[3.1.1]heptane-3-carboxylateC11H18O3[α]D20 = +50 (c 0.25, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3S,5R)
(1R,2S,3S,5R)-3-Hydroxymethyl-6,6-dimethylbicyclo[3.1.1]heptan-2-olC10H18O2[α]D20 = +27 (c 0.235, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3S,5R)
(1R,2S,3R,5R)-3-Hydroxymethyl-6,6-dimethylbicyclo[3.1.1]heptan-2-olC10H18O2[α]D20 = +47 (c 0.25, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3R,5R)
(1R,2S,3R,5R)-2-Hydroxy-6,6-dimethylbicyclo[3.1.1]heptane-3-carboxylic acidC10H16O3[α]D20 = +2 (c 0.25, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3R,5R)
(1R,2S,3S,5R)-2-Hydroxy-6,6-dimethylbicyclo[3.1.1]heptane-3-carboxylic acidC10H16O3[α]D20 = +57 (c 0.25, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3S,5R)
(1R,2S,3S,5R)-N-Benzyl-2-hydroxy-6,6-dimethylbicyclo[3.1.1]heptane-3-carboxamideC17H23NO2[α]D20 = +47 (c 0.265, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3S,5R)
(1R,2S,3R,5R)-N-Benzyl-2-hydroxy-6,6-dimethylbicyclo[3.1.1]heptane-3-carboxamideC17H23NO2[α]D20 = −10 (c 0.25 MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3R,5R)
(1R,2S,3S,5R)-3-Benzylaminomethyl-6,6-dimethylbicyclo[3.1.1]heptan-2-olC17H25NO[α]D20 = +46 (c 0.255, MeOH)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2S,3S,5R)
