Rhodium(II)‐Catalyzed [4+3] Cyclization of Triazoles with Indole Derivatives and Its Application in the Total Synthesis of (±)‐Aurantioclavine.

Main observation and conclusion: An efficient rhodium(II)‐catalyzed [4+3] cyclization reaction of 1‐sulfonyl‐1,2‐3‐triazoles and indoles was developed. Azepino[5,4,3‐ cd]indoles, which are widely distributed in ergot alkaloids with various biological activities, could be obtained in good to excellent yields. In addition, the total synthesis of (±)‐aurantioclavine was completed in four steps from the known compound 1a adopting this [4+3] cyclization as a key step. [ABSTRACT FROM AUTHOR]