Integrated Pd-catalyzed cross-coupling strategies for furnishing α-carbolines

Efficient synthetic strategies for furnishing α-carbolines have been developed by integrating various Pd-catalyzed reactions. The methods involve 1) regioselective 5- or 6- halogenation of α-carbolines which were synthesized through intramolecular Pd-catalyzed direct C-H arylation, and subsequent Pd-catalyzed cross coupling, 2) 8-triflation of α-carbolines constructed by Pd-catalyzed cyclization, followed by Pd-catalyzed cross-coupling reaction, 3) Pd-catalyzed cyclization to tetrahydro-α-carbolines and subsequent Suzuki reaction via the corresponding α-carboline 5-triflates.

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