- Synthesis of tertiary sec-alkylamines by the addition of grignard reagents to N,N-dialkylformamides mediated by Ti(OiPr)4 and Me3SiCl
-
A number of tertiary sec-alkylamines (22 examples, 29-80% yield) have been prepared according to a simple one-pot procedure by the addition of Grignard reagents to N,N-dialkylformamides in the presence of Ti(OiPr)4 and Me3SiCl. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Tomashenko, Olesya,Sokolov, Viktor,Tomashevskiy, Alexander,Buchholz, Herwig A.,Welz-Biermann, Urs,Chaplinski, Vladimir,De Meijere, Armin
-
experimental part
p. 5107 - 5111
(2009/06/17)
-
- Further studies of intramolecular motions in crystalline ammonium bromides by CP/MAS NMR
-
A series of nine compounds consisting of dimethyl, trimethyl and ethyldimethyl ammonium bromides in which the other alkyl group contains a (2-phenyl)ethyl moiety were synthesised and studied by CP/MAS NMR. The results of dynamic NMR studies on the solids suggest that there is a dramatically wide range of molecular motions occurring in this simple series of compounds. A combination of dynamic line shape analyses and Τ1ρ measurements reveals the considerable extent of intramolecular group motions including rotations of trimethylammonium, ethyldimethylammonium and phenyl groups. Rates of rotation and activation parameters for these molecular motions are derived where appropriate.
- Riddell, Frank G.,Rogerson, Martin
-
p. 249 - 255
(2007/10/03)
-
- Chemical Behavior of N-Alkyl-N-methylbenzylammonium N-Alkylide
-
N-Alkyl-N-methyl(4-substituted benzyl)ammonium N-alkylides (3), produced by fluoride ion induced desilylation of N-alkyl-N-methyl-N-(4-substituted benzyl)-1-(trimethylsilyl)alkylammonium iodides (2), were mainly converted into N-alkyl-N-methyl-1-(4-substituted benzyl)alkylamines (5, Stevens rearrangement products) and 4-substituted toluenes (8).Both compounds were produced via radical-forming and -destroying pathways from 2-substituted-6--5-methylene-1,3-cylohexadienes (4), which were initially formed from 3 by sigmatropic rearrangement.There is no direct migration pathway from 3 to 5.
- Okazaki, Seiji,Shirai, Naohiro,Sato, Yoshiro
-
p. 334 - 337
(2007/10/02)
-
- Carbon-13 nuclear magnetic resonance spectra of fentanyl analogs
-
Natural abundance carbon-13 chemical shifts are reported for the hydrochloride salts of fentanyl and fifteen analogs. The signals are assigned on the basis of chemical shift theory, SFORD multiplicities, signal intensities, comparisons with model compounds, and thiophene carbon-proton coupling constants. In addition to its forensic value, the data suggest that the solution conformations of the analogs are similar to that of fentanyl hydrochloride.
- Brine,Boldt,Huang,Sawyer,Carroll
-
p. 677 - 686
(2007/10/02)
-
- THE HIGHLY STEREOSELECTIVE CONVERSION OF N,N-DIMETHYLAMPHETAMINE INTO N-METHYLPSEUDOEPHEDRINE; A MIMIC OF THE ENZYME MEDIATED STEREOSPECIFIC BENZYLIC HYDROXYLATION OF 2-ARYLETHYLAMINES
-
Treatment of (S)-(η6-N,N-dimethylamphetamine)Cr(CO)3, with n-butyllithium below -40 deg C gives a stable benzylic carbanion via loss of the pro-R-benzylic proton.Warming of this anion above -40 deg C gives (η6-E-β-methylstyrene)Cr(CO), via an ElcB type elimination wilhst trapping with an electrophile below -40 deg C gives benzylically functionalised amphetamines with overall retention of configuration.The use of oxodiperoxymolybdenum(pyridine)hexamtehylphosphoramide as the electrophile gives optically pure (1S,2S)-N-methylpseudoephedrine after decomplexation.
- Blagg, Julian,Davies, Stephen G.
-
p. 4463 - 4472
(2007/10/02)
-
- Optically Active Amines. 31. Spectral Observations on the Substituted Benzene Chromophore
-
Examination of the isotropic absorption and circular dichroism spectra of para-substituted and 3,5-disubstituted α-phenyl- and α-benzylethylamines and their hydrochlorides indicates that the sign of 1Lb Cotton effects (CEs) of the be
- Smith, Howard E.,Neergaard, Jon R.,Paulis, Tomas de,Chen, Fu-Ming
-
p. 1578 - 1584
(2007/10/02)
-
- THE EFFECT OF PHENYL SUBSTITUENTS ON ELIMINATION STEREOCHEMISTRY: A MECHANISTIC MANIFOLD IN ALKOXIDE PROMOTED DECOMPOSITION OF 1-PHENYL-1-PROPYLTRIMETHYLAMMONIUM ION
-
Reactions of the positionally isomeric 1-phenyl-1-propyl (I) and 1-phenyl-2-propyltrimethylammonium (II) ions with CH3OK - CH3OH, t-C4H9OK - t-C4H9OH and t-C4H9OK - C6H6 systems have been investigated with aid of the deuterated analogues erythro-2-D-I, threo-2-D-I, 1-D-I and threo-1-D-II.At least five mechanistic components (anti-β-elimination, syn-β-elimination, α',β-elimination, Sommelet-Hauser rearrangement and SN2 substitution) have been found to participate in the reaction of the quaternary compound I, in proportions varying greatly with base-solvent combination.The corresponding reactions of the isomeric compound II proceeded in a more simple manner, withount the intervention of ylide pathways in the olefin as well as in the amine formation.The stereochemistry of β-elimination determined for the two phenyl-substituted 'onium compounds has been compared with that reported previously for structurally related aliphatic analogues.The "anomalously" low propensity for syn-elimination as well as the "anomalously" high values of trans/cis-olefin rations in anti-elimination stigmatizing the presence of phenyl substituents are proposed to originate from a lack of base-approach hindrance in the reaction.
- Machkova, Zuzana,Zavada, Jiri
-
p. 833 - 849
(2007/10/02)
-
- Inhibition of synaptosomal accumulation of l norepinephrine II: N aryloxyalkylphentermines, quaternary d amphetamines, and 3 aryloxypropylamines
-
The inhibitory potencies of a series of N substituted phentermines on the synaptosomal uptake of l norepinephrine were found to be similar to those of the corresponding amphetamines. Quaternization of N,N dimethyl d amphetamine diminished, but did not abolish, its inhibitory potency, indicating that a permanently charged cation is also effective. Since the addition of an aromatic moiety at the end of a four atom chain originating at the nitrogen of amphetamine or phentermine significantly increased inhibitor strength, several 3 aryloxypropylamines and 4 phenylbutylamine were tested, but they were much weaker inhibitors than dl amphetamine. Thus, the observed increase in inhibitor potency apparently was not simply the result of a specific interaction of the 'nonmimic' portion of the N substituted amphetamines or phentermines.
- Schaeffer,Cho,Fischer
-
p. 122 - 126
(2007/10/06)
-