216591-86-5Relevant articles and documents
Chiroptical Inversion of Europium(III) Complexes by Changing a Remote Stereogenic Center of a C2-Symmetric Bispyrrolidinoindoline Manifold
Taniguchi, Tomoaki,Tsubouchi, Akira,Imai, Yuki,Yuasa, Junpei,Oguri, Hiroki
, p. 15284 - 15296 (2018)
As an effort to integrate natural products chemistry and coordination chemistry, a diastereomeric pair of chiral alkaloidal manifolds composed of a bispyrrolidinoindoline (BPI) framework was designed and synthesized to generate luminescent EuIII complexes with switchable chiroptical properties. The C2-symmetric alkaloidal manifolds were linked with bis(benzimidazolyl)pyridine (BBIPy) as an achiral metal-binding component through substituents installed at the stereogenic 2/2′ positions of the BPI manifolds. The resulting diastereomeric pair of ligands, syn-L1 and anti-L2, allow pseudomirror symmetrical presentation of the metal-binding BBIPy units due to the stereogenic centers on the alkaloidal manifold. The ligand syn-L1 induces intramolecular coordination to form the 1:1 complex EuIII(syn-L1) composed of a single stranded metal helicate which exhibits a negative split Cotton effect. In contrast, the ligand anti-L2 led to a supramolecular assembly comprising the 2:2 complex EuIII2(anti-L2)2 consisting of a bimetallic double-stranded helicate which shows a positive split Cotton effect. Thus, the sp3 stereogenic centers in the BPI manifolds play pivotal roles in controlling both metal-ligand equilibria and chirality-switching of luminescent EuIII complexes. This approach, which exploits diastereomeric natural product-based manifolds, provides a relatively unexplored means for diversifying metal coordination modes and for controlling the chiroptical properties of the resultant luminescent lanthanoid complexes.
Design and syntheses of a series of novel serotonin3 antagonists
Hori,Suzuki,Yamamoto,Nakajima,Ozaki,Ohtaka
, p. 1832 - 1841 (2007/10/02)
From a structural comparison study between serotonin and serotonin3 (5- HT3) antagonists using a two-dimensional grid template composed of regular hexagons, we deduced structural modification patterns from agonists to antagonists, an
