Conformational Control of Flexible Molecules: Design and Synthesis of Novel Chiral 1,5-Diaza-cis-decalins
摘要:
Control of the conformational equilibria of 1,5-diaza-cis-decalins, a new class of chiral diamine ligands, has been investigated. Chiral 2,6- and 3,7-substituted derivatives of 1,5-diaza-cis-decalins were designed to stabilize the conformational form needed to chelate a lithium. These derivatives were synthesized in optically pure form starting from 1,5-diaza-cis-decalin. Due to the rigid and conformationally well-defined nature of these compounds, the potential of these compounds as chiral diamine ligands was investigated. Asymmetric lithiation-substitution reactions of N-Boc-pyrrolidine and N,N-diisopropyl-o-ethylbenzamide were performed using these ligands and up to 60% ee was obtained. For the latter substrate, results spanning a range from 32% ee (R) to 60% ee (S) were obtained (Deltaee = 92%) with 1,5-diaza-cis-decalin ligands differing only in the location of two methyl substituents. Unlike many other diamines that have been employed in asymmetric lithiation-substitution reactions, the limited conformational flexibility of the 1,5-diaza-cis-decalins is analogous to (-)-sparteine such that these results may permit the construction of structure-activity relationships.
Synthesis and conformational analysis of 2,6-dimethyl-1,5-diaza-cis-decalins
摘要:
The stereoselective synthesis of 2,6-dimethyl-1,5-diaza-cis-decalins with the dimethyl groups syn or anti to the angular hydrogens has been accomplished starting from 1,5-diaza-cis-decalin. From an NMR study of the conformational properties of all three 2,6-dimethyl-1,5-diaza-cis-decalins, the components which affect the conformational equilibrium have been identified. (C) 2001 Elsevier Science Ltd. All rights reserved.
Asymmetric Ruthenium-Catalyzed Hydrogenation of 2,6-Disubstituted 1,5-Naphthyridines: Access to Chiral 1,5-Diaza-<i>cis</i>-Decalins
作者:Jianwei Zhang、Fei Chen、Yan-Mei He、Qing-Hua Fan
DOI:10.1002/anie.201411105
日期:2015.4.7
developed. A wide range of 1,5‐naphthyridine derivatives were efficiently hydrogenated to give 1,2,3,4‐tetrahydro‐1,5‐naphthyridines with up to 99 % ee and full conversions. This facile and green protocol is applicable to the scaled‐up synthesis of optically pure 1,5‐diaza‐cis‐decalins, which have been used as rigid chelating diamine ligands for asymmetric synthesis.
Homogeneous Perdehydrogenation and Perhydrogenation of Fused Bicyclic N-Heterocycles Catalyzed by Iridium Complexes Bearing a Functional Bipyridonate Ligand
Homogeneous perdehydrogenation of saturated bicyclic 2,6-dimethyldecahydro-1,5-naphthyridine and perhydrogenation of aromatic 2,6-dimethyl-1,5-naphthyridine with release and uptake of five molecules of H-2 are efficiently achieved by iridium complexes bearing a functional bipyridonate ligand. Successive perhydrogenation and perdehydrogenation of 2,6-dimethyl-1,5-naphthryridine using a single iridium complex also proceed with the reversible inter-conversion of the catalytic species, depending on the presence or absence of H-2.
Conformational Control of Flexible Molecules: Design and Synthesis of Novel Chiral 1,5-Diaza-<i>cis</i>-decalins
作者:Zhenrong Xu、Marisa C. Kozlowski
DOI:10.1021/jo025503x
日期:2002.5.1
Control of the conformational equilibria of 1,5-diaza-cis-decalins, a new class of chiral diamine ligands, has been investigated. Chiral 2,6- and 3,7-substituted derivatives of 1,5-diaza-cis-decalins were designed to stabilize the conformational form needed to chelate a lithium. These derivatives were synthesized in optically pure form starting from 1,5-diaza-cis-decalin. Due to the rigid and conformationally well-defined nature of these compounds, the potential of these compounds as chiral diamine ligands was investigated. Asymmetric lithiation-substitution reactions of N-Boc-pyrrolidine and N,N-diisopropyl-o-ethylbenzamide were performed using these ligands and up to 60% ee was obtained. For the latter substrate, results spanning a range from 32% ee (R) to 60% ee (S) were obtained (Deltaee = 92%) with 1,5-diaza-cis-decalin ligands differing only in the location of two methyl substituents. Unlike many other diamines that have been employed in asymmetric lithiation-substitution reactions, the limited conformational flexibility of the 1,5-diaza-cis-decalins is analogous to (-)-sparteine such that these results may permit the construction of structure-activity relationships.
Synthesis and conformational analysis of 2,6-dimethyl-1,5-diaza-cis-decalins
作者:Marisa C. Kozlowski、Zhenrong Xu、A.Gil Santos
DOI:10.1016/s0040-4020(01)00370-2
日期:2001.5
The stereoselective synthesis of 2,6-dimethyl-1,5-diaza-cis-decalins with the dimethyl groups syn or anti to the angular hydrogens has been accomplished starting from 1,5-diaza-cis-decalin. From an NMR study of the conformational properties of all three 2,6-dimethyl-1,5-diaza-cis-decalins, the components which affect the conformational equilibrium have been identified. (C) 2001 Elsevier Science Ltd. All rights reserved.