posted on 2021-08-31, 20:06authored byJian Ren, Shihua Ding, Xiaonian Li, Ran Bi, Qinshi Zhao
A one-step synthesis of diversely
substituted pyrazolo[1,5-a]pyrimidines from saturated
ketones and 3-aminopyrazoles
is presented. This transformation involves the in situ formation of
α,β-unsaturated ketones via a radical process, followed
by [3+3] annulation with 3-aminopyrazoles in one pot. Mechanistic
studies have shown that the dual C(sp3)–H bond functionalization
of inactive ketones is required for the formation of the title compounds.
Notably, this dehydrogenative coupling process provides access to
a host of functionalized pyrazolo[1,5-a]pyrimidines
with antitumor potential from commercially available substrates.