- Potential Synthetic Adaptogens: V. Synthesis of Cage Monoamines by the Schwenk–Papa Reaction
-
The reduction of cage ketoximes under Schwenk–Papa reaction conditions was studied to establish that the d,l, d- and l-camphor oximes are smoothly reduced to the corresponding amines in high yields. At the same time, d,l-norcamphor and adamantan-2-one oximes undergo partial catalytic deoximation to form a mixture of the corresponding amines and alcohols.
- Brunilin, R. V.,Mkrtchyan, A. S.,Nawrozkij, M. B.,Novakov, I. A.,Vernigora, A. A.,Voloboev, S. N.,Vostrikova, O. V.
-
p. 1742 - 1748
(2020/01/11)
-
- Regioselective Radical Alkene Amination Strategies by Using Phosphite-Mediated Deoxygenation
-
Nitrogen-containing compounds are an essential motif in all disciplines of chemistry and the efficient synthesis of these frameworks is a highly sought-after goal. Presented here is a summary of recent efforts conducted by our group to develop radical-mediated amination strategies for the formal synthesis of primary amines from alkenes with exclusive anti-Markovnikov regioselectivity. We have found that N-hydroxyphthalimide is an effective reagent capable of supplying both the N and H atoms for alkene hydroamination in a group transfer radical addition-type mechanism. Furthermore, allyl-oxyphthalimide derivatives are similarly capable of radical group transfers and allow for the aminoallylation of an external alkene.
- Lardy, Samuel W.,Schmidt, Valerie A.
-
p. 2022 - 2026
(2019/11/05)
-
- Intermolecular Radical Mediated Anti-Markovnikov Alkene Hydroamination Using N-Hydroxyphthalimide
-
An intermolecular anti-Markovnikov hydroamination of alkenes has been developed using triethyl phosphite and N-hydroxyphthalimide. The process tolerates a wide range of alkenes, including vinyl ethers, silanes, and sulfides as well as electronically unbiased terminal and internal alkenes. The resultant N-alkylphthalimides can readily be transformed to the corresponding primary amines. Mechanistic probes indicate that the process is mediated via a phosphite promoted radical deoxygenation of N-hydroxyphthalimide to access phthalimidyl radicals.
- Lardy, Samuel W.,Schmidt, Valerie A.
-
supporting information
p. 12318 - 12322
(2018/10/02)
-
- Direct Primary Amination of Alkylmetals with NH-Oxaziridine
-
A method for the primary electrophilic amination of primary, secondary, and tertiary organometallic substrates from a bench-stable NH-oxaziridine reagent is described. This facile and highly chemoselective transformation occurs at ambient temperature and without transition metal catalysts or purification by column chromatography to provide alkylamine products in a single step. Density functional theory (DFT) calculations revealed that, despite the basicity of alkylmetals, the direct NH-transfer pathway is favored over proton and O-transfer.
- Behnke, Nicole Erin,Kielawa, Russell,Kwon, Doo-Hyun,Ess, Daniel H.,Kürti, László
-
supporting information
p. 8064 - 8068
(2019/01/04)
-
- Iridium-catalyzed intermolecular hydroamination of unactivated aliphatic alkenes with amides and sulfonamides
-
The intermolecular addition of N-H bonds to unactivated alkenes remains a challenging, but desirable, strategy for the synthesis of N-alkylamines. We report the intermolecular amination of unactivated α-olefins and bicycloalkenes with arylamides and sulfonamides to generate synthetically useful protected amine products in high yield. Mechanistic studies on this rare catalytic reaction revealed a resting state that is the product of N-H bond oxidative addition and coordination of the amide. Rapid, reversible dissociation of the amide precedes reaction with the alkene, but an intramolecular, kinetically significant rearrangement of the species occurs before this reaction with alkene.
- Sevov, Christo S.,Zhou, Jianrong,Hartwig, John F.
-
supporting information; experimental part
p. 11960 - 11963
(2012/09/08)
-
- COMPOSITIONS AND METHODS FOR CYCLOFRUCTANS AS SEPARATION AGENTS
-
The present invention relates to derivatized cyclofructan compounds, compositions comprising derivatized cyclofructan compounds, and methods of using compositions comprising derivatized cyclofructan compounds for chromatographic separations of chemical species, including enantiomers. Said compositions may comprise a solid support and/or polymers comprising derivatized cyclofructan compounds.
- -
-
Page/Page column 45-49; 63
(2010/12/31)
-
- Comparison of large-scale routes to manufacture chiral exo-2-norbornyl thiourea
-
Two routes aimed at the manufacture of chiral exo-2-norbornyl thiourea (1) on large scale are described. The first approach involves five chemical steps and hinges on a classical resolution via diastereomeric salt formation. The synthesis utilizes amine 2 as the resolution handle. The second approach includes two chemical steps and a chiral chromatography of (±)-1. Despite the larger initial investment necessary to acquire the chiral stationary phase used in the chromatographic approach, the shorter reaction sequence and efficiency of the chromatographic separation make the second route a more attractive option for long-term applications.
- Caille, Seb,Boni, Jerome,Cox, Geoffrey B.,Faul, Margaret M.,Franco, Pilar,Khattabi, Saab,Klingensmith, Liane M.,Larrow, Jay F.,Lee, James K.,Martinelli, Michael J.,Miller, Larry M.,Moniz, George A.,Sakai, Kenichi,Tedrow, Jason S.,Hansen, Karl B.
-
experimental part
p. 133 - 141
(2010/04/29)
-
- Intermolecular Cope-type hydroamination of alkenes and alkynes using hydroxylamines
-
The development of the Cope-type hydroamination as a method for the metal- and acid-free intermolecular hydroamination of hydroxylamines with alkenes and alkynes is described. Aqueous hydroxylamine reacts efficiently with alkynes in a Markovnikov fashion to give oximes and with strained alkenes to give N-alkylhydroxylamines, while unstrained alkenes are more challenging. N-Alkylhydroxy-lamines also display similar reactivity with strained alkenes and give modest to good yields with vinylarenes. Electron-rich vinylarenes lead to branched products while electron-deficient vinylarenes give linear products. A beneficial additive effect is observed with sodium cyanoborohydride, the extent of which is dependent on the structure of the hydroxylamine. The reaction conditions are found to be compatible with common protecting groups, free OH and NH bonds, as well as bromoarenes. Both experimental and theoretical results suggest the proton transfer step of the N-oxide intermediate is of vital importance in the intermolecular reactions of alkenes. Details are disclosed concerning optimization, reaction scope, limitations, and theoretical analysis by DFT, which includes a detailed molecular orbital description for the concerted hydroamination process and an exhaustive set of calculated potential energy surfaces for the reactions of various alkenes, alkynes, and hydroxylamines.
- Moran, Joseph,Gorelsky, Serge I.,Dimitrijevic, Elena,Lebrun, Marie-Eve,Bedard, Anne-Catherine,Seguin, Catherine,Beauchemin, Andre M.
-
supporting information; experimental part
p. 17893 - 17906
(2009/07/18)
-
- ISOXAZOLES AND THEIR USE IN THE TREATMENT OF ISCHEMIC DISEASES
-
The present invention provides a compound of formula I, or a pharmaceutically acceptable salt thereof. These compounds are useful for the treatment of neurological, neurodegenerative, ischemic and inflammatory disorders. Accordingly, the invention also provides pharmaceutically acceptable compositions comprising the compounds of the invention and methods of utilizing those compounds and compositions in the treatment of neurological, neurodegenerative, ischemic and inflammatory disorders.
- -
-
-
- PREPARATION OF ISOMERICALLY PURE ALKYLAMINES VIA THE REACTION OF DIMETHYLALKYLBORANES WITH CHLORAMINE
-
Dimethylborane was used to hydroborate alkenes regiospecifically.The resultant dimethylalkylboranes react with ammonium hydrochloride and sodium hypochlorite to yield isomerically pure alkylamines.
- Kabalka, George W.,Wang, Zhe,Goudgaon, Nganna M.
-
p. 2409 - 2414
(2007/10/02)
-
- THE REACTION OF ORGANOBORANES WITH TRIMETHYLSILYL AZIDE IN A NEUTRAL MEDIUM: SYNTHESIS OF PRIMARY AMINES
-
A facile method for the preparation of primary amines using trimethylsilyl azide and trialkylboranes in a neutral protic solvent is described.
- Kabalka, George W.,Goudgaon, Naganna M.,Liang, Yanhong
-
p. 1363 - 1370
(2007/10/02)
-
- ORGANOBORANES FOR SYNTHESIS. 7. AN IMPROVED GENERAL SYNTHESIS OF PRIMARY AMINES FROM ALKENES via HYDROBORATION-ORGANOBORANE CHEMISTRY
-
Triorganylboranes, R3B, and diorganylborinicesters, R2BOR', react readily with preformed chloramine or hydroxylamine-O-sulfonic acid to produce the corresponding primary amines, RNH2.However, the product of the reaction following hydrolysis is the boronic acid, RB(OH)2, limiting the yield to 67percent for R3B and to 50percent for R2BOR'.This problem has now been overcome with the help of lithium dimethylborohydride, readily converted in situ to dimethylborane.The hydroboration of representative alkenes by dimethylborane provides the corresponding monoorganyldimethylborane, RMe2B.Treatment of this intermediate with hydroxylamine-O-sulfonic acid provides the desired amines, RNH2, in isolated yields of 73percent to 95percent.The reaction proceeds with complete retention, reproducing the precise structure of the organic group in the organoboranes, RMe2B.
- Brown, Herbert C.,Kim, Kee-Won,Srebnik, Morris,Singaram, Bakthan
-
p. 4071 - 4078
(2007/10/02)
-
- HIGHLY STEREOSELECTIVE SYNTHESIS OF CYCLIC PRIMARY AMINES VIA HYDRIDE REDUCTIONS.
-
The reduction of p,p'-dimethoxybenzhydryl imines of substituted cyclohexanones with lithium tri-sec-butyl or tri-ethylborohydride and subsequent cleavage of the resulting secondary amines with formic acid affords the corresponding axial cyclohexyl primary amines with high stereoselectivity.
- Hutchins, Robert O.,Su, Wei-Yang
-
p. 695 - 698
(2007/10/02)
-
- REDUCTION OF KETOXIMES WITH THE BICYCLOHEPTANE AND TRICYCLO2,6>HEPTANE STRUCTURES
-
Only the corresponding primary amines were obtained during the reduction of the oximes of bicycloheptan-2-one and 1-methyl- and 1-ethylbicycloheptan-2-ones with sodium in alcohol, whereas mixtures of primary amines and 3-azabicyclooctanes were formed with lithium aluminium hydride.The yield of the last products increases with inctrease in the reaction temperature.Only primary amines were obtaines during the reduction of the 1-methyl- and 1-ethyltricyclo2,6>heptan-3-ones oximes both with sodium in alcohol and with lithium aluminum hydride.
- Ordubadi, M. D.,Pekhk, T. I.,Belikova, N. A.,Rakhmanchik, T. M.,Plate, A. F.
-
p. 678 - 683
(2007/10/02)
-
- 2-Norbornanediazonium Ions Revisited
-
The reactions of 2-norbornanediazonium ions have been reinvestigated with the aid of optically active and deuterium-labeled precursors.Enantiomeric purities were determined by direct VPC methods, and deuterium distributions by 2H NMR spectroscopy.The product pattern is strongly affected by the polarity of the solvent. exo-Diazonium ions 13 in water yield racemic exo alcohol (s,kΔ) of the norbornadiazonium ions.Optically active exo products are typical of nonpolar solvents and originate most probably from assymetric ion pairs.Model studies with optically active bicyclooct-3-en-2-amine (36) provide conclusive evidence that ion-pair colapse may lead to optically active products even in the case of delocalized achiral carbocations.
- Kirmse, Wolfgang,Siegfried, Rainer
-
p. 950 - 956
(2007/10/02)
-