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.

No abstract

Acids and Alkylboranes. -A number of phosphaadamantanes like (I) are prepared and tested as ligands in the Suzuki coupling. The most effective one is the derivative (Ia) which facilitates the reaction of alkyl halides and tosylates containing β-hydrogens. -(BRENSTRUM, T.; GERRISTMA, D. A.; ADJABENG, G. M.; FRAMPTON, C. S.; BRITTEN, J.; ROBERTSON, A. J.; MCNULTY, J.; CAPRETTA*, A.; J. Org. Chem. 69 (2004) 22, 7635-7639; Dep. Chem., McMaster Univ., Hamilton, Ont. L8S 4M1, Can.; Eng.) -Jannicke 12-057

Amines Q 0120 Phospha-adamantanes as Ligands for Organopalladium Chemistry: Aminations of Aryl Halides. -The use of the catalytic combination Pd2(dba)3·CHCl3 OPA allows a high-yielding amination of aryl halides. -(GERRISTMA, D.; BRENSTRUM, T.; MCNULTY, J.; CAPRETTA*, A.; Tetrahedron Lett. 45 (2004) 45, 8319-8321; Dep. Chem., McMaster Univ., Hamilton, Ont. L8S 4M1, Can.; Eng.) -Mais 08-078