Synthesis, reactivity and catalytic properties of rhodium complexes of (R,R)-1-benzyl-3,4-dithioetherpyrrolidines

Abstract

Complexes [Rh(cod)(degusR)]ClO4, where cod is 1,5-cyclooctadiene and degusR represents the homochiral dithioethers (R,R)-1-benzyl-3,4-bis(methylsulfanyl)pyrrolidine, (R,R)-1-benzyl-3,4-bis(isopropylsulfanyl)pyrrolidine and (R,R)-1-benzyl-3,4-bis(phenylsulfanyl)pyrrolidine were prepared and characterized. Their reactivity with CO and PPh3 was investigated. The complexes were assayed as catalysts in hydroformylation of styrene, hydrogenation of acrylic acids and hydroboration of styrene. Although these complexes containing dithioethers behave as catalytic precursors in hydroformylation reaction, the results suggest that mononuclear hydride rhodium carbonyl species is responsible for the catalytic activity. The cationic complexes are not active in the hydrogenation of acrylic acids in the conditions tested. These complexes are moderately active in the hydroboration of styrene with catecholborane, but their selectivities are not satisfactory.