Palladium-catalyzed formation of secondary and tertiary amines from aryl dihalides with air-stable ferrocenyl tri- and diphosphines: Synthesis and X-ray structure of efficient catalysts beyond [PdCl2(DPPF)]

摘要

Robust, air-stable tridentate and bidentate ferrocenylphosphines l,2-bis(diphenylphosphino)-l'-(diisopropylphosphino)-4-tert-butylferrocene, L5, andl,l'-bis(diisopropylphosphino)-3,3'-bis(tert-butyl)ferro-cene, L9, combined with 1 mol% of [PdCl(η~3-C3H5)]2 led to two new catalytic systems which allow the coupling of aniline derivatives with mono- and dihaloarenes to form functionafeed diarylamines and triarylamines. The excellent selectivity of the reactions avoids the deleterious dehalogenation of the substrates and products. The X-ray structure characterization of the related complex [PdCl2(L9)] is reported in which ligand L9 in its meso form is significantly distorted.