New Chiral Zinc Complexes: Synthesis, Structure, and Induction of Axial Chirality

Abstract

We describe an efficient methodology for the preparation of new chiral zinc complexes by assembling dynamically racemic biphenol derivatives and chiral 1,2-diamines with suitable zinc(II) precursors. Mononuclear and dinuclear zinc(II) complexes were formed from differently substituted biphenols. The solid-state and solution structural characterization of the resulting compounds allowed us to demonstrate a preferential sense of induced axial chirality for mononuclear complexes, a phenomenon that was not observed for the dinuclear ones.

Supramolecular chirality transfer in a stereodynamic catalysts

“…When combined with suitable chiral auxiliaries, stereochemically flexible ligands have already been very successfully applied in a variety of enantioselective transformations. [10][11][12][13] So far, the stereochemistry of these ligands has been controlled via hydrogen bonding, 14 hydrogen bonding and formation of supramolecular structures, [15][16][17] coordination of additional chiral coligands, 18 chiral counter-ions, 19,20 and chiral ionic liquids. 21 The aim of this study was to investigate the product or product mimic induced chirality transfer 22 from a nonstereoselective interaction site in a stereodynamic ligand.…”

Transformation of One-Dimensional Achiral Structure to Three-Dimensional Chiral Structure: Mechanistic Study and Catalytic Activities of Chiral Structure

“…Symmetry breaking can induce chirality in the final structure by affecting the nucleation or crystal growth. − The example of induced chirality through symmetry breaking where the final product does not contain any chiral unit is very rare. This process has an advantage compared to spontaneous resolution due to the enantiopure product formation, where as spontaneous resolution produces opposite handedness or racemic twins. , There are several reports on chiral symmetry breaking, but the proper mechanism or factors repsonsible for this are not very clear. − According to Kondepudi et al, during the stirring of the reactions mixture, secondary crystal nuclei may rapidly clone the parent structure. This is known as chiral autocatalysis.…”

Supramolecularly Regulated Ligands for Asymmetric Hydroformylations and Hydrogenations

“…[4] Supramolecular interactionsh ave been used to construct the skeletons of the enantioselective catalysts with unprecedented ease, [5] or even to introduce stereogenicity into the catalyst. [6] Within this context, regulation of ac atalyst refers to modificationo fi ts active site upon bindingo fa ne ffectorm olecule at ad istinct site (knowna st he regulation site). Progress has been made in regulating the size and shape of ac hiral catalyst by using ar egulation agent (RA).…”