First Total Synthesis of Bauerine C

The first total synthesis of Bauerine C, a unique indoloquinazoline alkoloid, has been achieved from readily available 2,3‐dichloroaniline. The key step is the Japp–Klingmann condensation between 2,3‐dichloroaniline and ethyl‐2‐acetyl‐5‐phthalimido pentanoate to get 3‐[(2,3‐dichlorophenyl)‐hydrozono]‐pipiridin‐2‐one, which cyclizes to 7,8‐dichloro‐2,3,4,9‐tetrahydro‐β‐carbolin‐1‐one, which can be methylated by dimethyl sulphate to give 7,8‐dichloro‐9‐methyl 2,3,4,9‐tetrahydro‐β‐carbolin‐1‐one. This N‐methyl derivative is then subjected to dehydrogenation with 2,3‐dichloro‐5,6‐dicayano‐1,4‐benzoquinone (DDQ) to give the target compound Bauerine C.     

The synthesis of 1,1-disubstituted tetrahydro-β-carbolines induced by iodine

A mild access to 1,1-disubstituted tetrahydro-β-carbolines is described. Tryptamine is subjected to Pictet-Spengler cyclization with various ketones using iodine.     

An efficient one-pot synthesis of indolyl-4H-chromene derivatives

Chemistry of Heterocyclic Compounds - A new one-pot three-component reaction for the synthesis of indolyl-4H-chromene derivatives has been developed. The synthesis was achieved by reacting...     

Terpenes to Ionic Liquids: Synthesis and Characterization of Citronellal-Based Chiral Ionic Liquids

A series of new chiral ionic liquids have been prepared and characterized starting from a simple, economical, and commercially available monoterpene, citronellal. The aldehyde functionality in citronellal is converted into a Schiff base using an amine, followed by reduction with Raney nickel to give the desired quaternary amine. Most of the ionic liquids generated using this procedure are found to be liquids at room temperature.