Tug-of-War between Two Distinct Catalytic Sites Enables Fast and Selective Ring-Opening Copolymerizations was written by Wang, Jianqun;Zhu, Yinuo;Li, Maosheng;Wang, Yanchao;Wang, Xianhong;Tao, Youhua. And the article was included in Angewandte Chemie, International Edition in 2022.Application In Synthesis of Isopropylisothiocyanate The following contents are mentioned in the article:
Ring-opening copolymerizations have emerged as a powerful approach towards the creation of sustainable polymers. Typical H-bonding catalysts for ring-opening are subject to a single catalytic site. Here we describe a H-bond-donor/Lewis-acidic-boron organocatalyst featuring two distinct catalytic sites in one mol. The ring-opening copolymerization of epoxides with anhydride mediated by these modular, and tunable catalysts achieves high selectivity (>99% polyester selectivity) and markedly higher activity compared to either of the di-thiourea analogs or any combinations of them. Calculations and exptl. studies reveal that the superior catalytic performance arises from tug-of-war between two differentiated catalytic sites: thiourea pulls off the propagating chain-end from boron center, simultaneously enhancing the role of monomer activation and also nucleophilicity of the propagation intermediates. This study involved multiple reactions and reactants, such as Isopropylisothiocyanate (cas: 2253-73-8Application In Synthesis of Isopropylisothiocyanate).
Isopropylisothiocyanate (cas: 2253-73-8) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Esters are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility.Application In Synthesis of Isopropylisothiocyanate
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics