Chemo- and Diastereoselective Cycloisomerization/[2 + 3] Cycloaddition of Enynamides: Synthesis of Spiropyrazolines as Potential Anticancer Reagents

A silver-catalyzed one-pot cycloisomerization/[2 + 3]
cycloaddition
of enynamides with in situ generated nitrile imines
has been developed. Unlike the well-established cycloisomerization/[4
+ n] cycloadditions of enynamides, this strategy
provides efficient access to a new type of spiropyrazolines, which
exhibit an anti-proliferation effect on multiple tumor cell lines.
The compound 3u exhibits obvious anticancer activity
by inducing apoptosis in RKO cells. The combination of compound 3u and an autophagy inhibitor could improve its anti-proliferation
capacities.