Synthesis and biological activity of Para-substituted 3′-phenyl docetaxel analogs

An expedient route for semisynthetic para-modified 3′-phenyl docetaxel analogs is described using the initial regioselective iodination of the oxazolidinecarboxylate 3. Palladium catalyzed coupling reactions of the iodo intermediate 4 with alkenyl and aryl boronic acids and alkynes led after alkaline hydrolysis to a series of N,O-protected para-substituted phenylisoserines 6. Coupling with 10-deacetyl-7, 10-O-diTroc-baccatin III followed by standard deprotections and acylation afforded the title analogs.