Efficient and Practical One-Pot Conversions of N-Tosyltetrahydroisoquinolines into Isoquinolines and of N-Tosyltetrahydro-β-carbolines into β-Carbolines through Tandem β-Elimination and Aromatization
An efficient, practical, and general method for conversions of N-tosyltetrahydroisoquinolines (N-tosyl-THIQs) into isoquinolines and of N-tosyltetrahydro-β-carbolines (N-tosyl-THBCs) into β-carbolines is described. Treatment of N-tosyl-THIQs or N-tosyl-THBCs with base in dimethyl sulfoxide afforded dihydroisoquinolines or dihydro-β-carbolines as intermediates, and these were then oxidized in situ by
A series of bivalent β-carbolines with a piperazine group spacer between 3-methylene units were synthesized and their cytotoxic activities in vitro were evaluated. Compounds 7e and 7g exhibited potent cytotoxic activity.