Zobrazeno 1 - 10
of 85
pro vyhledávání: '"Hubertus Ahlbrecht"'
Publikováno v:
Russian Journal of General Chemistry. 72:1620-1624
The relative stabilities of tautomeric forms of 3-methyl-1-phenylpyrazol-5-one and its 5-thioxo and 5-selenoxo analogs, as well as their acid-base properties in the gas phase, were estimated in terms of nonempirical calculations and density functiona
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::7c413ef4c420a974de8afba46f0cfa4e
https://doi.org/10.1023/a:1023395903052
https://doi.org/10.1023/a:1023395903052
Autor:
Jennie Weston, Hubertus Ahlbrecht
Publikováno v:
Tetrahedron. 55:2289-2306
Structural investigations (NMR) show that both 1-dimethylaminoallyllithium ( 4 ) and potassium ( 2 ) exist exclusively in the endo conformation in THF. Ab initio calculations also conclude that the endo -structure is thermodynamically more stable tha
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::dbb2dfe6cf015e25941063c2f387ca3a
https://doi.org/10.1016/s0040-4020(99)00015-0
https://doi.org/10.1016/s0040-4020(99)00015-0
Publikováno v:
Tetrahedron. 55:2609-2624
The carbolithiation of cinnamyl methyl ether 4 with tert-butyllithium, benzyllithium, and allyllithium is achieved in good yields. Consecutive treatment with electrophiles yields in all three cases a good diastereoselectivity thus confirming earlier
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::03f5350b5e8cc4e36ebca824f2cb22ea
https://doi.org/10.1016/s0040-4020(99)00018-6
https://doi.org/10.1016/s0040-4020(99)00018-6
Publikováno v:
European Journal of Organic Chemistry. 1998:1371-1377
3-Substituted aliphatic ketones 10 have been obtained in excellent optical yields by alkylation of the aminoallyllithium compound endo-8, a homoenolate equivalent of hexane-3-one, using prolinol ether (SMP) as the chiral auxiliary. The intermediate e
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::917fd8f613b1317eeba88fdd59de74ca
https://doi.org/10.1002/(sici)1099-0690(199807)1998:7<1371::aid-ejoc1371>3.0.co
https://doi.org/10.1002/(sici)1099-0690(199807)1998:7<1371::aid-ejoc1371>3.0.co
Autor:
Peter Gerdes, Jan Runsink, Dietrich Mannes, Michael Marsch, Dieter Enders, Gerhard Raabe, Jochen Kirchhoff, Hubertus Ahlbrecht, Horst Sommer, Gernot Boche
Publikováno v:
European Journal of Organic Chemistry. 1998:63-72
Investigations aimed at elucidating the structure of lithiated α-amino nitriles B have led to the identification of N-lithio α-amino nitrile anions as characteristic structural features. Their preparations, crystal structures, and solution structur
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::521aa57f138dd0532354e04bab3e1b4f
https://doi.org/10.1002/(sici)1099-0690(199801)1998:1<63::aid-ejoc63>3.0.co
https://doi.org/10.1002/(sici)1099-0690(199801)1998:1<63::aid-ejoc63>3.0.co
Publikováno v:
Chemische Berichte. 130:683-686
α-(Dimethylamino)benzyllithium (1a) and its complexes, 1b–f, have been characterized by their solid-state 13C-NMR spectra. The spectra are comparable to those recorded in solution and can be used to reveal the structures of the different solvates
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::b9be85a7b6e2240c76fc6e36d57165b4
https://doi.org/10.1002/cber.19971300603
https://doi.org/10.1002/cber.19971300603
Autor:
Hubertus Ahlbrecht, Galina Tschmutova
Publikováno v:
Zeitschrift für Naturforschung B. 52:535-542
Quantum chemical calculations on the title compounds have been performed at different levels of theory in order to obtain a reasonable model capable of treating even larger systems with reliable results. The HF/6-31G*//PM3 model is shown to describe
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::5693421d0f1fa8cd439d728dae8bf443
https://doi.org/10.1515/znb-1997-0415
https://doi.org/10.1515/znb-1997-0415
Autor:
Jennie Weston, Hubertus Ahlbrecht
Publikováno v:
Journal of the Chemical Society, Perkin Transactions 2. :1003-1006
Methyl-substituted enamines assume overwhelmingly a gauche–out conformation in the absence of steric hinderance. A change of global minimum to the orthogonal–out structure occurs in the presence of steric interactions (Z-substitution pattern). Ca
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::577aee67bf2018a021a1012fbdee1afd
https://doi.org/10.1039/a606273c
https://doi.org/10.1039/a606273c
Autor:
Hubertus Ahlbrecht, Andreas Kramer
Publikováno v:
Chemische Berichte. 129:1161-1168
The hydroxyalkylation of lithiated 3-[(S)-2-(methoxymethyl)-pyrrolidino]-1,3-diphenylpropene (2) with aldehydes is completely regioselective giving homoaldol adducts in good yields. The simple diastereoselectivity is low with typical ratios ranging b
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::17c881e2ef15b8f5c4d18c3143519575
https://doi.org/10.1002/cber.19961291004
https://doi.org/10.1002/cber.19961291004
Publikováno v:
Tetrahedron. 52:10025-10042
The carbolithiation of N-methyl-3-phenyl-prop-2-enylamine with tert-butyllithium leads to the monomeric benzyllithium compound 7 in good yield. The consecutive reaction with electrophiles exhibits a high anti diastereoselectivity, opposite to what ha
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ea74c0e52514d81e18a2011f62ccf4f3
https://doi.org/10.1016/0040-4020(96)00535-2
https://doi.org/10.1016/0040-4020(96)00535-2