Continuous flow: A straightforward synthetic strategy for the immobilization of Eosin Y onto Merrifield-resin was successfully developed. The easy-to-synthesize new material efficiently promoted the photooxidation of tertiary amines, especially operating with continuous flow catalytic reactors. When using the iminium-ions in situ or in a telescoped fashion the resulting Mannich-products could be isolated with high degrees of diastereo- and enantioselectivity (up to 90 % e.e.), simply using air as terminal oxidant. The same reactor was reused several times, with no loss of efficiency and no apparent material degradation.
A new easy-to-synthesize solid supported Eosin Y and its application in the building of a catalytic continuous flow reactor is reported. The fluidic device was employed to perform tertiary amines in-flow photooxidations followed by a nucleophile addition, with overall productivity increased by one order magnitude. When using the iminium-ions in situ generated or in a telescoped fashion, the resulting Mannich-products were isolated with high diastereoselectivity and up to 90 % enantioselectivity, simply using air as terminal oxidant.Zum Volltext