- Synthesis of pyrrolizidines by cascade reactions of N- alkenylaziridinylmethyl radicals
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Pyrrolizidines were synthesized in a one-step-reaction from 2- (bromomethyl)aziridines via a cascade of radical reactions involving aziridinylmethyl radicals. N-allylaminyl radicals and carbon-centered pyrrolidinyl radicals.
- De Smaele, Dirk,Bogaert, Piet,De Kimpe, Norbert
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Read Online
- Synthesis method of 2-methyl-3-(4-tert-amylphenyl) propanol
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The invention discloses a synthesis method of 2-methyl-3-(4-tert-amylphenyl) propanol, which specifically comprises the following steps: 1, reacting propionaldehyde with primary amine R1-NH2 in the presence of a dehydrating agent to generate a compound A;
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Paragraph 0017-0020
(2021/01/30)
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- 5-Benzylidene-4-oxazolidinones potently inhibit biofilm formation in Methicillin-resistant Staphylococcus aureus
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Investigation into the biological function of 5-benzylidene-4-oxazolidinones revealed dose-dependent inhibition of biofilm formation in Methicillin-resistant S. aureus (MRSA). This structurally unusual class of small molecules inhibit up to 89% of biofilm formation with IC50 values as low as 0.78 μM, and disperse pre-formed biofilms with IC50 values as low as 4.7 μM. Together, these results suggest that 4-oxazolidinones represent new chemotypes to enable the study of bacterial biofilms with small molecule chemical probes.
- Edwards, Grant A.,Shymanska, Nataliia V.,Pierce, Joshua G.
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supporting information
p. 7353 - 7356
(2017/07/11)
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- Synthesis of enantiomerically pure model compounds of the glucose-6-phosphate-T1-translocase inhibitors kodaistatins A-D. Inferences with regard to the stereostructure of the natural products
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The kodaistatins A and C (5a,b) inhibit a step in glucose-metabolism at ~100 nM concentrations. This makes them potential 'leads' in the therapy of diabetes. We elucidated the (S)-configuration of the side-chain stereocenter of kodaistatin A by ozonolysis/reduction. The 13C NMR shifts of kodaistatin A model cis-11 suggest that the diol moiety in the dihydroxycyclopentanone core of kodaistatin is trans-configured. This model was prepared from the Feringa lactone (21) and (S)-2-methylbutanal (27) in 23 steps (14 steps in the longest linear sequence). We employed the same strategy for the simplified kodaistatin A model iso-cis-12, which resulted from the same substrates in 11 steps (6 steps in the longest linear sequence). The cyclopentenone cores of both targets stemmed from a C4+C1 approach. The C4 components were masked 'tartaric ketones' (16a,b) and a masked 'tartaric aldehyde' (18), respectively. The C1 components were the lithium-derivatives of the side-chain bearing phosphonates 19 and 22, respectively. The desired acylation/deprotonation/Horner-Wadsworth- Emmons tandem reaction succeeded in a single operation with the 'tartaric aldehyde' 18 but required partly or exclusively additional operations when we incorporated the 'tartaric ketones' 16a or 16b, respectively. The 'tartaric ketones' 16a,b contained an α-siloxyethyl substituent. It is noteworthy that it had to be introduced by adding the benzyltrimethylammonium enolate of lactone 18 to acetaldehyde because the lithium enolate of this lactone fragmented by an acetone-releasing β-elimination.
- Wüster, Thomas,Kaczybura, Natasza,Brückner, Reinhard,Keller, Manfred
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p. 7785 - 7809
(2013/08/23)
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- NOVEL COMPOUNDS AS CANNABINOID RECEPTOR LIGANDS
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The present application relates to isothiazolylidene containing compounds of Formula (I) wherein R1, R2, R3, R4, and L are as defined in the specification, compositions comprising such compounds, and methods for treating conditions and disorders using such compounds and compositions.
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Page/Page column 68
(2010/06/11)
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- Reaction of aldimine anions with vinamidinium chloride: Three-component access to 3-alkylpyridines and 3-alkylpyridinium salts and access to 2-alkyl glutaconaldehyde derivatives
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(Chemical Equation Presented) N-tert-Butylimino derivatives of aldehydes were deprotonated with LDA and reacted with vinamidinium chloride to give 2-alkylaminopentadienimine derivatives, which were isolated as their corresponding hydrochloride in 68-81% yield. Reaction of these derivatives with ammonium acetate or salts of primary amines, in n-butanol at 80°C, afforded the corresponding 3-alkylpyridines or 3-alkylpyridinium salts in high yield. Alkaline hydrolysis of 2-alkylaminopentadieneimine derivatives allowed a practical accesss to potassium salts of 2-alkylglutaconaldehyde.
- Wypych, Jean-Charles,Nguyen, Tuan Minh,Benechie, Michel,Marazano, Christian
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p. 1169 - 1172
(2008/09/18)
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- NOVEL COMPOUNDS AS CANNABINOID RECEPTOR LIGANDS
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The present application relates to isothiazolylidene containing compounds of Formula (I) wherein R1, R2, R3, R4, and L are as defined in the specification, compositions comprising such compounds, and methods of treating conditions and disorders using such compounds and compositions.
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Page/Page column 52
(2008/12/08)
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- A modified Robinson annulation process to α,α-disubstituted-β,γ-unsaturated cyclohexanone system. Application to the total synthesis of nanaimoal
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4-Cyano-2-cyclohexenones were found to be susceptible to reductive alkylation reactions, giving the corresponding 2,2-disubstituted-3-cyclohexenone derivatives in a completely regioselective manner. This newly developed methodology has been successfully applied towards the total synthesis, in racemic form, of the marine natural product nanaimoal.
- Liu, Hsing-Jang,Ly, Tai Wei,Tai, Chia-Liang,Wu, Jen-Dar,Liang, Jinn-Kwei,Guo, Jiunn-Cheh,Tseng, Nai-Wen,Shia, Kak-Shan
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p. 1209 - 1226
(2007/10/03)
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- Synthesis and evaluation of a putative acyl tetramic acid intermediate in tenellin biosynthesis in Beauveria bassiana. A new role for tyrosine
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The acyltetramic acid 6 previously proposed as a putative intermediate in tenellin biosynthesis in Beauveria bassiana has been synthesised in two isotopically labelled forms. This compound was not incorporated into tenellin and was not identifiable in extracts of B. bassiana and is unlikely to be involved in tenellin biosynthesis. On the other hand a re-evaluation of the role of tyrosine reveals that it is a good precursor to tenellin and is probably generated in vivo by the action of a phenylalanine hydroxylase directly from L-phenylalanine. Thus the long held contention that acyltetramic acid 6 undergoes oxidative ring expansion to a pyridone no longer appears a valid hypothesis for tenellin biosynthesis.
- Moore, M. Caragh,Russell, J. Cox,Duffin, Gordon R.,O'Hagan, David
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p. 9195 - 9206
(2007/10/03)
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- Synthesis of 3-alkenylamines, 4-alkenylamines and 3-allenylamines via a transamination procedure
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3-Alkenylamines, 4-alkenylamines and 3-allenylamines were synthesized conveniently by potassium t-butoxide induced transamination of α-vinylaldimines, α-allylaldimines or α-allenylaldimines followed by hydrolysis with aqueous oxalic acid.
- De Kimpe, Norbert,De Smaele, Dirk,Hofkens, Arn,Dejaegher, Yves,Kesteleyn, Bart
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p. 10803 - 10816
(2007/10/03)
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- Some reactions of ammonia and primary amines with propanal, 2-chloroethanal, 2,2-dichloroethanal and 2,2,2-trichloroethanal in acetonitrile
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The reaction of ammonia with propanal in acetonitrile produces the hexahydrotriazine, 1, in good yield. The corresponding reaction of chloroethanal yields the cyclic trimer 16 but only in poor yield. Increasing chloro-substitution in the aldehyde stabilises the initially formed carbinolamines and disfavours trimerisation. Imines formed by reaction of primary amines with the aldehydes are relatively stable. Those formed from aliphatic amines may undergo slow dimerisation by C-C bond formation and this may be accompanied by loss of amine to yield products containing a conjugated double-bond system. Kinetic and equilibrium data are reported for both the forward and reverse reactions involving interconversion of propanal and ammonia with 1 in acetonitrile-water mixtures. The results indicate that dehydration of the carbinolamine is rate determining.
- Crampton, Michael R.,Lord, Simon D.,Millar, Ross
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p. 909 - 914
(2007/10/03)
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- α,α-Cyclobisalkylation of aldehydes via ω-haloaldimines
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The construction of a cycloalkyl ring at the α-position of aldehydes by cyclization of ω-haloaldimines is described. Alkylation of the corresponding aldimines with α,ω-dihaloalkanes followed by treatment with LDA results in a convenient access to α,α-cycl
- Stevens, Christian V.,De Kimpe, Norbert G.,Katritzky, Alan R.
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p. 3763 - 3766
(2007/10/02)
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- Comparison of the Tautomerization and Hydrolysis of Some Secondary and Tertiary Enamines
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N-Phenylcyclohex-1-en-1-amine, N-(p-chlorophenyl)cyclohex-1-en-1-amine, the N-aryl-2-methylprop-1-en-1-amines, Me2C=CHNLC6H4X, L = H, D, X = H, p-Cl, p-Me, p-MeO, m-NO2, the N-alkyl-2-methylprop-1-en-1-amines, Me2C = CHNDR, R = Me, Et and the (E)-N-alkylprop-1-en-1-amines, MeHC = CHNDR, R = Me, t-Bu, were generated in solution from their N-trimethylsilyl derivatives and characterized by NMR spectroscopy.N-(p-Nitrophenyl)-2-methylprop-1-en-1-amine was isolated from the reaction of isobutyraldehyde and p-nitroaniline, and appreciable amounts (>10percent) of the N-arylcyclohex-1-en-1-amines and N-aryl-2-methylcyclohex-1-en-1-amines were found to be present at equilibrium in DMSO-d6 solution when the aryl group was phenyl, p-chlorophenyl, m-nitrophenyl, or p-nitrophenyl.The kinetics of hydrolysis of all the N-aryl secondary enamines obtained in the above ways were measured in aqueous solution and compared with those of the corresponding N-methyl tertiary enamines.With all enamines there was a region of pH in which kobsd was proportional to 10-pH, and under such conditions it was considered that the rate-determining step was C-protonation.This was supported by the isotope effect kH(1+)/kD(1+) = ca. 3, the observation of general acid catalysis, the much faster rate of hydrolysis of the corresponding imines, and the negative ρ- values.It was found that in the cyclohexenyl series the secondary and tertiary enamines were hydrolyzed at similar rates when the substituents in the aryl group were the same, but in the 2-methylcyclohexenyl and 2-methylpropenyl series the secondary enamines were hydrolyzed much faster than the corresponding tertiary enamines.This was attributed to the tertiary enamines being hindered from attaining the most favorable conformation for p-? conjugation.
- Capon, Brian,Wu, Zhen-Ping
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p. 2317 - 2324
(2007/10/02)
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- SYNTHESIS OF RACEMIC DOMINCALURE - THE AGGREGATION PHEROMONE OF THE LESSER GRAIN BORER Rhyzopertha dominica
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The sec-amyl esters of 2-methylpent-2E-enoic and 2,4-dimethylpent-2E-enoic acids, constituting the aggregation pheromone of the lesser grain borer Rhyzopertha dominica, have been synthesized stereospecifically in high yield from the products of the aldol condensation of propionaldehyde and isobutyraldehyde.The 2-methyl- and 2,4-dimethylpent-2E-enals were oxidized to the corresponding acids, which were converted into the chlorides and these into the corresponding sec-amyl esters.The geometric purity of the products was shown by their PMR spectra (250 MHz).
- Cheskis, B. A.,Yarutich, A. P.,Lebedeva, K. V.,Moiseenkov, A. M.
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p. 103 - 105
(2007/10/02)
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- REACTIONS OF N-1-(2,2-DICHLOROALKYLIDENE)AMINES WITH POTASSIUM CYANIDE: SYNTHESIS OF β-CHLORO-α-CYANOENAMINES, α-CHLOROIMIDATES AND 2-AMINO-5-CYANOPYRROLS
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Reaction of N-1-(2,2-dichloroalkylidene)amines, prepared by chlorination of aliphatic aldimines with N-chlorosuccinimide, with excess of potassium cyanide in methanol gave β-chloro-α-cyanoenamines.When the reaction was carried out for a longer period, α-c
- Verhe, Roland,Kimpe, Norbert De,Buyck, Laurent De,Tilley, Marc,Schamp, Niceas
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p. 131 - 142
(2007/10/02)
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