Dipolar Cycloaddition of Cyclopropene with <i>N</i> , <i>N</i> -Cyclic Azomethine Imine: A Straightforward Protocol for Diazabicyclo[3.1.0]hexane Scaffold with Promising In Vitro Anti-proliferative Activities

The [3 + 2] dipolar cycloaddition reaction between cyclopropene and <i>N</i>,<i>N</i>-cyclic azomethine imine is reported, offering an efficient protocol for the construction of the diazabicyclo[3.1.0]hexane skeleton. This method features good yields, robust functional group tolerance (62 examples), and diastereoselectivity. In vitro antiproliferative activity screening of the product library against five strains of tumor cell lines (HL-60, A549, HepG2, MDA-MB-231, and SW480) showed that the scaffold exhibits promising proliferation inhibitory effects. Among them, the HL-60 cell line is the most sensitive with IC₅₀ values being as low as 8.05 ± 0.40 μM. An SAR analysis of these compounds is presented.