Enantioselektive Katalyse, IX. Neue optisch reine 3,4-Bis(phosphanyl)pyrrolidine mit Phenyl-und Anisylgruppen sowie deren Palladium-und Rhodiumkomplexe

Enantioselective Catalysis, IX[1]. – New Optically Pure 3,4-Bis(phosphanyl)pyrrolidines with Phenyl and Anisyl Groups Including Their Palladium and Rhodium Complexes Methods for the synthesis of the diastereomeric mixture of the [P(R,S),3R,4R,P′(R,S)]1-1-(tert1-butoxycarbonyl)1-3,4-bis[(2-methoxyphenyl)phenylphosphanyl]pyrrolidines (2a, b, c) are described. For the chromatographic separation and purification of the ligand diastereomers we transformed them into the PdI21-complexes (10a, b, c). The structure of (PR,3R,4R,P′R)1-1-(tert1-butoxycarbonyl)1-3,4-bis[(2-methoxyphenyl)phenylphosphanyl]pyrrolidine-P,P′}diiodopalladium (10 b) was determined by X-ray diffraction. Treatment of the palladium complexes with KCN yielded the pure phosphanes. The rhodium complexes (11a, 11b, 11c), which can be used as catalysts in enantioselective hydrogenations, were obtained by reaction of [Rh(COD)2]BF4 with compound 2a, 2b, or 2c.