Chiral Metal–Organic Framework Decorated with TEMPO Radicals for Sequential Oxidation/Asymmetric Cyanation Catalysis
作者:Zijian Li、Yan Liu、Xing Kang、Yong Cui
DOI:10.1021/acs.inorgchem.8b01630
日期:2018.8.20
cocrystallizing achiral (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)-substituted tricarboxylate and enantiopure VO(salen)-derived dipyridine ligands. The chiral MOF can function as an efficient heterogeneous catalyst for the sequential alcoholoxidation/asymmetric cyanation of aldehyde reactions with enhanced activity and enantioselectivity compared to the homogeneous counterpart.
wide variety of alkyl halides with mercury(I) and/or (II) nitrate in 1,2-dimethoxyethane, mercury(II) acetate in acetic acid, aqueous mercury(II) perchlorate, and mercury(II) perchlorate in alcohol solvents have been investigated; as a result, simple high yield procedures for the conversion of alkyl halides into the corresponding nitrate esters, acetate esters, alcohols and ethers have been developed.
of the essential molecules. In this field, the absolute asymmetric synthesis of α‐aminoacids is a major challenge. Herein, we report access, by chemical means, to tertiary α‐aminoacid derivatives in up to 96 % ee without using any chiral reagent. In our strategy, the dynamic axial chirality of tertiary aromatic amides is frozen in a crystal and is responsible for the stereoselectivity of the subsequent
compound in a chiral conformation is used as the unique source of chirality in an absolute asymmetric synthesis of tertiary amino acids. The dynamic axial chirality of tertiary aromatic amides is frozen in a crystal (see picture) and is responsible for the stereoselectivity of the deprotonation/alkylation (see scheme). α‐Amino acid derivatives are synthesized in up to 96 % ee.
A concise SAR-analysis of antimicrobial cationic amphipathic barbiturates for an improved activity-toxicity profile
作者:Manuel K. Langer、Ataur Rahman、Hymonti Dey、Trude Anderssen、Francesco Zilioli、Tor Haug、Hans-Matti Blencke、Klara Stensvåg、Morten B. Strøm、Annette Bayer
DOI:10.1016/j.ejmech.2022.114632
日期:2022.11
yield the highest broad-spectrum activity and cationic trimethylated quaternary amine groups to exert narrow-spectrum activity against Gram-positive bacteria. n-Propyl hydrocarbon linkers proved to be the best compromise between potency and haemolytic activity. The combination of two different lipophilic side chains allowed for further fine-tuning of the biological properties. Using these insights