Hammett Correlation of Nornicotine Analogues in the Aqueous Aldol Reaction: Implications for Green Organocatalysis
摘要:
A series of meta- and para-substituted 2-arylpyrrolidines were synthesized and examined for their ability to catalyze an aqueous aldol reaction under buffered conditions. Kinetic analysis of arylpyrrolidine-catalyzed reactions displayed a linear Hammett correlation with rho = 1.14 (R-2 = 0.996), indicating that the reaction is accelerated by electron-withdrawing aryl rings. These results show promise for the development of a synthetically viable aqueous organo-catalyst.
Indenoisoquinolines and dihydroindenoisoquinolines have been synthesized possessing a nitro-substituted isoquinoline ring in an effort to explore the effects of electron-withdrawing substituents on biological activity. The in vitro anticancer activities of these molecules have been tested in the National Cancer Institute's screen of 55 cell lines. The compounds have also been tested for topoisomerase I (topI) inhibition. The results indicate that these substances are a potent class of topI inhibitors with sub-micromolar cytotoxicity mean graph midpoints (MGM) and topI inhibition equal to camptothecin. (C) 2004 Elsevier Ltd. All rights reserved.
Optimization of the Indenone Ring of Indenoisoquinoline Topoisomerase I Inhibitors
Two series of indenoisoquinoline topoisomerase I inhibitors have been prepared to investigate optimal substituents on the indenone ring at the 9-position. The more exhaustive series was prepared using a nitrated isoquinoline ring that has been previously demonstrated to enhance biological activity. After preliminary biological evaluation, a more focused series of inhibitors was prepared utilizing a 2,3-dimethoxy-substituted isoquinoline ring. The results of the two series indicate the existence of superior functional groups such as methoxy, fluorine, and cyano for the indenoisoquinoline 9-position. Interestingly, these functional groups coincide with established structure-activity relationships for the 11-position of camptothecin.