Assembly of 4-Aminoquinolines via Palladium Catalysis: A Mild and Convenient Alternative to SNAr Methodology
摘要:
4-Aminoquinolines, classically prepared via SNAr chemistry from an amine and 4-haloquinoline, are important scaffolds in medicinal chemistry. Interest in these compounds prompted us to explore palladium catalysis as an alternative to the existing methods for their preparation. Initial results followed by an iterative screening paradigm confirmed Pd(OAc)(2)/ DPEphos/K3PO4 as a mild and convenient alternative for the formation of the C-N bond in 4-aminoquinolines. A description of the screen and the scope of this methodology are discussed herein.
Quinine, quinidine and analogs thereof, are prepared by reacting a 4-quinolyllithium compound with a 4,5-erythro-5-ethyl(or vinyl)-quinuclidine-2 .xi.-carboxaldehyde or the corresponding quinuclidine-2-carboxylic acid alkyl ester. Also described, inter alia, is the preparation of a 4,5-erythro-5-ethyl(or vinyl)-quinuclidine-2 .xi.-carboxaldehyde, and a 4,5-erythro-5-ethyl(or vinyl)-quinuclidine-2 .xi.-carboxylic acid and esters thereof. The end products are useful as anti-malarial and antiarrhythmic agents.
[1,2]-Brook rearrangement can dearomatize aromatic N-heterocycles! Through a one-pot four-step process that includes lithiation, nucleophilic addition, Brook rearrangement, and dearomatization reaction, we enable the formation of non-aromatic N-heterocycles with functional capabilities starting from readily available precursors. Subsequent functionalization reactions provide access to a diverse compound
11-Substituted 2,3-dimethoxy-8,9-methylenedioxybenzo[i]phenanthridine derivatives as novel topoisomerase I-targeting agents
作者:Wei Feng、Mavurapu Satyanarayana、Yuan-Chin Tsai、Angela A. Liu、Leroy F. Liu、Edmond J. LaVoie
DOI:10.1016/j.bmc.2008.08.018
日期:2008.9
Several 11-substituted benzo[i]phenanthridine derivatives were synthesized, and their TOP1-targeting activity and cytotoxicity were assessed. Comparative data indicate that TOP1-targeting was often the primary molecular target associated with their cytotoxicity. Several 11-aminoalkyl derivatives, 11-aminocarboxy derivatives as well as the 11-[(2-dimethylamino)ethyl]carboxamide of 2,3-dimethoxy-8,9-methylenedioxybenzo[i]phenanthridine were synthesized and did exhibit considerable cytotoxicity with IC50 values ranging from 20 to 120 nM in the human lymphoblast tumor cell line RPMI8402. (C) 2008 Elsevier Ltd. All rights reserved.