Several new ortho bridged biphenyls mimicking the structure of (-)-rhazinilam were synthesized and evaluated as cytotoxic compounds and as inhibitors of microtubules disassembly. These included azadibenzo[a,c]cyclononene derivatives having an ester, urea or carbamate function present in the 9-membered ring linking the two phenyl moieties. The compound bearing a carbamate function instead of the amide group of rhazinilam interacts better with tubulin than (-) rhazinilam, (C) 1998 Elsevier Science Ltd. All rights reserved.
Synthesis and biological evaluation of a-Ring biaryl-carbamate analogues of rhazinilam
An improvement of the synthesis of biphenyl-carbamate 2a, the most active analogue of rhazinilam 1 so far, was performed using the Pd-catalyzed borylation/Suzuki coupling (BSC) method developed in our laboratories. The preparation of A-ringanalogues of 2a bearing electron-withdrawing or donating groups is reported according to this new synthetic scheme. The antitubulin properties as well as the cytotoxicity
A catalytic asymmetric synthesis of the axially chiral bridged biaryl (-)-2, a structural analogue of natural (-)-rhazinilam possessing original antimitotic properties, is described. The key step is an intermolecular asymmetric Suzukicoupling, furnishing the nonbridged biaryl (-)-6, precursor of (-)-2, with up to 40% ee using binaphthyl ligand 7a. Various known or new binaphthyl and ferrocenyl phosphines