Calcium-catalyzed Pictet-Spengler reactions

Pictet-Spengler reactions of m-tyramine and aldehydes produced tetrahydroisoquinolines in the presence of a catalytic amount of CaOCH(CF3)2]2. This reaction occurs with a variety of aryl, heteroaryl, and alkyl aldehydes, producing tetrahydroisoquinolines in high yield and with high regioselectivity. This calcium-promoted Pictet-Spengler reaction provides a mild alternative to the traditional Br?nsted acids typically employed in these reactions.