From Center-to-Multilayer Chirality: Asymmetric Synthesis of Multilayer Targets with Electron-Rich Bridges

Abstract

Asymmetric synthesis of new atropisomerically multilayered chiral targets has been achieved by taking advantage of the strategy of center-to-multilayer chirality and double Suzuki–Miyaura couplings. Diastereomers were readily separated via flash column chromatography and well characterized. Absolute configuration assignment was determined by X-ray structural analysis. Five enantiomerically pure isomers possessing multilayer chirality were assembled utilizing anchors involving electron-rich aromatic connections. An overall yield of 0.69% of the final target with hydroxyl attachment was achieved over 11 steps from commercially available starting materials.

A new chiral phenomenon of orientational chirality, its synthetic control and computational study

“…Since there is only a single interaction (the heavy black line in the model, Figure 8B) existing in each of the three atropisomers, there are three energy barriers instead of six in the previous atropisomerism to be expected. It should be pointed out that the nomenclature of previous molecular architectures follows the Cahn−Ingold−Prelog (CIP) rules (Tang et al, 2022b;Jin et al, 2022). However, finding a nomenclature rule for the present chirality framework seems difficult.…”

“…It should be pointed out that the nomenclature of previous molecular architectures follows the Cahn−Ingold−Prelog (CIP) rules ( Tang et al, 2022b ; Jin et al, 2022 ). However, finding a nomenclature rule for the present chirality framework seems difficult.…”

“…Meanwhile, pseudo or quasi C 2 symmetry has also become an interesting and important addition to chirality documents. For instance, organo sandwich chirality shows unique “S” and “Ƨ” ( anti S) patterns of pseudo C 2 symmetry ( Tang et al, 2022b ; Jin et al, 2022 ), and their chiral aggregates displayed various spectroscopic properties ( Figure 2 ).…”

Enantioselective synthesis of [1,1′-binaphthalene]-8,8′-diyl bis(diphenylphosphane) and its derivatives

“…13,14 The peri-positioned functional groups at the 8,8 0 position on the binaphthyl backbone can affect the topology and provide a unique microenvironment for asymmetric transformation. [15][16][17] Herein, we report the enantioselective synthesis of two new C 2 symmetric 8,8 0 -disubstituted binaphthyl ligands via chiral resolution of racemic 7,7 0 -dimethoxy-[1,1 0 -binaphthalene]-2,2 0 -diol. The nal products can be obtained in 3.1% and 11.4% yields in total via two more step transformations.…”

Four-layer folding framework: design, GAP synthesis, and aggregation-induced emission

“…The design of these targets is highly demanded to search for desired chemical, physical, and biological properties. This is particularly applicable to the research on multilayer monomers, oligomers, and polymers, which exhibit photoelectronic properties ( Wu et al, 2019 ; Tang et al, 2022a ; Tang et al, 2022b ; Wang et al, 2022 ; Xia et al, 2023 ). For example, a through-space transfer through singlet fission (SF) was proven to involve the absorption of photons by two electronically interacting chromophores to generate a singlet exciton state, which is followed by the rapid formation of two triplet excitons ( Chen et al, 2018 ).…”