Catalyst-Free Synthesis of Polycyclic Spiroindolines by Cascade Reaction of 3-(2-Isocyanoethyl)indoles with 1-Sulfonyl-1,2,3-triazoles

A catalyst-free cascade reaction of 3-(2-isocyanoethyl)indolesand 1-sulfonyl-1,2,3-triazoles was realized. This dearomative spirocyclizationprovided an efficient protocol to synthesize a series of polycyclicindolines bearing spiro-alpha-carboline in moderate to high yieldsin one step under thermal reaction conditions.

Automated summary

A catalyst-free cascade reaction between 3-(2-isocyanoethyl)indoles and 1-sulfonyl-1,2,3-triazoles was developed. This dearomative spirocyclization provided an efficient one-step synthesis of various polycyclic indolines bearing spiro-alpha-carboline in moderate to high yields under thermal reaction conditions.