thiourea and akuammicine

We describe enantioselective syntheses of strychnos and chelidonium alkaloids. In the first case, indole acetic acid esters were established as excellent partner nucleophiles for enantioselective cooperative isothiourea/Pd catalyzed α-alkylation. This provides products containing indole-bearing stereocenters in high yield and with excellent levels of enantioinduction in a manner that is notably independent of the N-substituent. This led to concise syntheses of (-)-akuammicine and (-)-strychnine. In the second case, the poor performance of ortho-substituted cinnamyl electrophiles in the enantioselective cooperative isothiourea/Ir catalyzed α-alkylation was overcome by appropriate substituent choice, leading to enantioselective syntheses of (+)-chelidonine, (+)-norchelidonine, and (+)-chelamine.

Topics: Alkaloids; Alkylation; Benzophenanthridines; Berberine Alkaloids; Catalysis; Chelidonium; Humans; Indoles; Iridium; Palladium; Sirtuin 1; Stereoisomerism; Strychnine; Strychnos; Thiourea