Fluorous and traceless synthesis of substituted indole alkaloids
Mei-Jung Lin1, Wei Zhang, Chung-Ming Sun
1Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan.
Abstract:
The fluorous traceless synthesis of substituted indole alkaloids is carried out first by attaching the 3-(perfluorooctyl)propanol with Boc protected L-tryptophan. The reaction of perfluoroalkyl (Rfh)-tagged tryptophan esters with various aldehydes undergoes Pictet-Spengler reaction to give cis and trans stereoisomers of tetrahydro-beta-carbolines. The nucleophilic addition of the piperidine nitrogen across various isocyanates is followed by the cyclization of ureas and simultaneous rupture of the fluorous tag to afford the hydantoin ring fused tetrahydro-beta-carbolines. All the fluorous-tag compounds are purified by solid-phase extraction (SPE) through Fluoro Flash cartridges.
Related Concept Videos
Preparation of Alcohols via Substitution Reactions
Alcohols can be synthesized from alkyl halides via nucleophilic substitution reactions. The highly polar carbon-halogen bond in the substrate makes halide a good leaving group. The hydroxide ion or water can act as a nucleophile to take the place of halide and form an alcohol. The substitution reactions occur via two different reaction pathways, SN1 or SN2, depending on the nature of carbon attached to the halide.
Primary alcohols are synthesized from primary alkyl halides, and the...
Synthesis of α-Substituted Carbonyl Compounds: The Stork Enamine Reaction
Preparation of 1° Amines: Gabriel Synthesis
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Preparation of Alkynes: Dehydrohalogenation
Alkynes can be prepared by dehydrohalogenation of vicinal or geminal dihalides in the presence of a strong base like sodium amide in liquid ammonia. The reaction proceeds with the loss of two equivalents of hydrogen halide (HX) via two successive E2 elimination reactions.
Base-Promoted α-Halogenation of Aldehydes and Ketones


