Metallocenium salts as activating groups:Knoevenagle condensations of methyl and 1,1'-dimethyl cobalticinium and rhodicinium salts

摘要

Previous investigators1-4 have employed ferrocenyl derivatives as Strong pi-electron donors in the preparation of highly conjugated organic molecules such as 1a-c with high values of the second order hyperpolarizability,beta.In general,the addition of electron donating substituents to the ferrocenyl group,increasing the value of n or increasing the strength of the acceptor X-A increased the value of beta.The highest values of beta obtained were comparable to the best obtained for other organic molecules.