No abstract

In memory of Ferenc FülöpA one-pot two-step chemo-enzymatic approach for the functionalization of substituted 1,2,3,4-tetrahydroisoquinolines (THIQs) was developed. The system combines monoamine oxidase (MAO)-catalyzed imine formation with Ugi-type threecomponent reaction in an aqueous buffer without intermediate isolation. The two steps were separately optimized for buffer and pH to obtain the expected products. MAOs enabled the functionalization of fifteen THIQs by oxidation to imines, while the Ugi-Joullié-reaction was successfully carried out with eight carboxylic acids and eight isonitriles. 41 products were isolated giving access to valuable building blocks for medicinal chemistry applications. Gram-scale transformation demonstrated the utility of the described protocol for organic synthesis.