Lewis acid-controlled reactions of zirconacyclopentadienes with isocyanates and isothiocyanates. One-pot three- or four-component synthesis of multiply substituted iminocyclopentadienes and butadiene-tethered 1,6-bisamides and electrophilic cyclization was written by Hu, Qiaoshu;Lu, Jiang;Wang, Congyang;Wang, Chao;Xi, Zhenfeng. And the article was included in Tetrahedron in 2007.Recommanded Product: 2,4-Dichlorophenylisothiocyanate This article mentions the following:
Multiply substituted zirconacyclopentadienes including bicyclic zirconacyclopentadienes and zirconaindenes reacted with isocyanates and isothiocyanates in the presence of Lewis acids to afford iminocyclopentadienes and conjugated 1,6-bisamides, depending on the nature of Lewis acids, isocyanates, and isothiocyanates used. Only in the presence of BF3 could iminocyclopentadienes be obtained in high isolated yields when zirconacyclopentadienes were treated with isocyanates. On the contrary, BF3 could not mediate the reaction of zirconacyclopentadienes with isothiocyanates. For the reactions of zirconacyclopentadienes with isothiocyanates, EtAlCl2 was found effective to generate iminocyclopentadienes as the products. Interestingly, however, for the reactions of zirconacyclopentadienes with isocyanates, EtAlCl2 was found to work very differently from BF3. Instead of iminocyclopentadienes, conjugated 1,6-bisamides and conjugated mono-amides were obtained as products in high isolated yields from the reactions of zirconacyclopentadienes with isocyanates, depending on the substituents of isocyanates. The reaction path and products could be controlled by Lewis acids. As a demonstration of the usefulness of thus obtained unsaturated bisamides, electrophilic cyclization using acids, NBS, and I2 was carried out. Electrophilic cyclization of multisubstituted conjugated 1,6-bisamide derivatives afforded cyclic iminoethers in excellent yields with perfect selectivity. Only one of the amide groups took part in the electrophilic cyclization. In the experiment, the researchers used many compounds, for example, 2,4-Dichlorophenylisothiocyanate (cas: 6590-96-1Recommanded Product: 2,4-Dichlorophenylisothiocyanate).
2,4-Dichlorophenylisothiocyanate (cas: 6590-96-1) belongs to organic chlorides. Organic chlorides can cause corrosion in pipelines, valves and condensers, and cause catalyst poisoning. The hydrocarbon processing industry (HPI) and others are affected by damage caused by these substances.While alkyl bromides and iodides are more reactive, alkyl chlorides tend to be less expensive and more readily available. Alkyl chlorides readily undergo attack by nucleophiles.Recommanded Product: 2,4-Dichlorophenylisothiocyanate
Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics