Stereoselective migration of sterically hindered organoboranes in cyclic and acyclic systems. A stereoselective allylic C–H activation reaction
作者:Eike Hupe、Dmitri Denisenko、Paul Knochel
DOI:10.1016/j.tet.2003.09.043
日期:2003.11
The thermal migration of cyclic and acyclic organoboranes were studied. In most cases, a stereoselective 1,2-dyotropic migration was observed, allowing the stereocontrol of three contiguous chiral centers. Scope and limitations of this thermal migration are presented.
The structure-affinity relationships (SAR) between the N-terminii of a series of alpha-methyl-tryptophanylphenethylamide derivatives and the cholecystokinin (CCK) B receptor are discussed. A series of compounds with the general formula R-X-alpha-methyl-tryptophanylphenethylamide was prepared, where R is a cycloalkyl, a bicycloalkyl or a tricycloalkyl group and X is a urethane, thiourethane, amide, urea or a sulphinamide linking group. The CCK-B receptor binding affinities of these are discussed. The SAR form part of a systematic program for the rational design of 'dipeptoid' analogues of the neuropeptide CCK. Beginning with 1,1-dimethylpropyl (+/-)-[1-(1H-indol-3-ylmethyl)-1-methyl-2-oxo-2-[(2-phenylethyl)amino]ethyl]carbamate (IC50 = 4720 nM on CCK-B binding affinity) the N-terminal moiety was systematically changed for groups of varying size, shape and lipophilicity until the optimal N-terminal group was obtained and the favoured linking group chosen, resulting in the compound tricyclo[3.3.1.1(3,7)]dec-2-yl(R)-[(1H-indol-3-ylmethyl)-1-methyl-2-oxo-2-[(2-phenylethyl)amino]ethyl]carbamate with an IC50 = 32 nM on CCK-B receptor binding affinity.
Hueckel, Justus Liebigs Annalen der Chemie, 1938, vol. 533, p. 1,26
作者:Hueckel
DOI:——
日期:——
Hueckel,W. et al., Justus Liebigs Annalen der Chemie, 1961, vol. 645, p. 115 - 162