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 ),3 R ,4 R ,P′( R,S )]1‐1‐( tert 1‐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 PdI 2 1‐complexes ( 10a, b, c ). The structure of (P R ,3 R ,4 R ,P′ R )1‐1‐( tert 1‐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 ]BF 4 with compound 2a, 2b , or 2c .