An efficient one-pot decarboxylative aromatization of tetrahydro-β-carbolines by using N-chlorosuccinimide: total synthesis of norharmane, harmane and eudistomins

A facile method for the synthesis of a variety of β-carbolines and their natural products such as norharmane ( 2a ), harmane ( 2b ), eudistomins I, N, T, and U ( 6 , 7 , 9 and 10 , respectively) has been successfully developed via a decorboxylative aromatization tool by employing N -chlorosuccinimide (NCS) as a mild and efficient reagent. Gratifyingly, this reagent system proceeds in a one-pot manner and converted all the tetrahydro-β-carboline acids into their corresponding decorboxylative aromatic products with good to excellent yields. Additionally, this system works well in the case of tetrahydro-β-carboline esters to produce their aromatic partners in high yields.