Generation of a small library of highly electron-rich 2-(Hetero)aryl-substituted phenethylamines by the Suzuki-Miyaura reaction: A short synthesis of an apogalanthamine analogue

The Suzuki-Miyaura reaction is presented as a versatile procedure for the synthesis of a small library of highly electron-rich 2-[4,5-dimethoxy-2-(hetero)arylphenyl]ethylamines. Microwave-irradiation accelerates the reaction tremendously and furnishes superior yields. The difficult oxidative addition of the catalyst to a highly electron-rich and ortho-substituted system could be performed easily, and the proto-deboronation during cross-coupling reactions involving the highly electron-withdrawing (2-formylphenyl)boronic acid could be minimized. Enhanced yields and complete compatibility with aqueous conditions were found. This strategy was developed en route towards the synthesis of an apogalanthamine analogue. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.