Synthesis of Highly Functionalized Tricyclic Chromenopyrazole Frameworks via Intramolecular Azomethine Imine 1,3-Dipolar Cycloaddition (IAIDC)

摘要

A general protocol for the synthesis of angularly substituted tricyclic chromenopyrazoles via an intramolecular azomethine imine 1,3-dipolar cycloaddition (IAIDC) reaction of O-allylated salicylaldehydes (derived from bromo derivatives of Baylis-Hillman adducts) and aryl hydrazines has been described for the first time. This reaction creates two rings (six and five-membered) via the formation of one C-C bond and two C-N bonds. Moreover, the products are formed with two chiral centers with high diastereoselectivity and stereospecificity. Some of the synthesized compounds were examined for the fluorescent properties and found to exhibit strong fluorescence in the blue region.