Role of Regioisomeric Bicyclo[3.3.0]octa-2,5-diene Ligands in Rh Catalysis: Synthesis, Structural Analysis, Theoretical Study, and Application in Asymmetric 1,2- and 1,4-Additions
作者:Tina Mühlhäuser、Alex Savin、Wolfgang Frey、Angelika Baro、Andreas J. Schneider、Heinz-Günter Döteberg、Florian Bauer、Andreas Köhn、Sabine Laschat
DOI:10.1021/acs.joc.7b02601
日期:2017.12.15
values up to 99%. In Hayashi–Miyaura reactions, however, the complexes showed poor catalytic activity. When complexes [RhCl(CS-L)]2 with CS-symmetric ligand or mixtures of [RhCl(C2-L)]2 and [RhCl(CS-L)]2 were employed in 1,2-additions, racemic addition products were observed, suggesting a C═C isomerization of the diene ligands. X-ray crystal structure analysis of both Rh complexes formed from the [RhCl(C2H4)2]2
为了研究区域异构二烯配体对Rh配合物的形成和催化活性的影响,一系列C 2-和C S对称的2,5-二取代的双环[3.3.0] octa-2,5-dienes C通过同时去质子/亲电捕集两个氧代官能团,由魏斯二酮分别合成2 -L和C S -L,并在[RhCl(C 2 H 4)2 ] 2存在下研究了催化行为。配合物[的RhCl(c ^ 2 -L)] 2轴承Ç 2对称的配体有效地催化了N-甲苯磺酰基亚胺与(S)-二芳基胺的不对称芳基化,其收率和ee值高达99%。然而,在Hayashi–Miyaura反应中,络合物显示出较差的催化活性。当配合物[的RhCl(C小号-L)] 2与ç š -对称配体或混合物[的RhCl(c ^ 2 -L)] 2和[的RhCl(Ç小号-L)] 2在1,2-加法被采用观察到外消旋加成产物,表明二烯配体的C═C异构化。由[RhCl(C 2 H 4)2 ] 2前体和配体C 2 -L和C