Synthesis of β-carbolines via a silver-mediated oxidation of tetrahydro-β-carbolines

The oxidation of tetrahydro-beta-carbolines to beta-carbolines using silver carbonate was developed as an alternative to current methods. The oxidation is extremely mild and provides the products in modest to good yields after purification. A number of functional groups are tolerated by this methodology, including reduction-sensitive groups which are often cleaved with other methods. Though the mechanism is not fully understood, the reaction proceeds in an open flask, is not sensitive to light or moisture, and provides a viable synthetic route to compounds that are not easily prepared via other methodologies. (C) 2017 Elsevier Ltd. All rights reserved.