Phosphaadamantanes as ligands for palladium catalyzed cross-coupling chemistry: library synthesis, characterization, and screening in the Suzuki coupling of alkyl halides and tosylates containing beta-hydrogens with boronic acids and alkylboranes.

ABSTRACT

A 15-member library of phosphaadamantane ligands has been prepared via P-arylation of 1,3,5,7-tetramethyl-2,4,8-trioxa-6-phosphaadamantane. Screening of this tertiary phosphine collection has allowed for the rapid determination of the most suitable ligand, specifically 1,3,5,7-tetramethyl-6-(2,4-dimethoxyphenyl)-2,4,8-trioxa-6-phosphaadamantane, for facilitating Suzuki-type couplings of alkyl halides or tosylates containing beta-hydrogens with either boronic acids or alkylboranes.