Recently, the direct oxidative
α-C(sp
3)–H functionalization of alcohols leading to the construction of C—C bonds is emerging as a powerful entry to assemble alcohol skeletons [
4]. The group of Guo/Duan [5a] and Liang [5b] independently disclosed interesting oxidative hydroxyalkylarylation of
N-arylacrylamides with alcohols, but selective preparation of carbonyl-containing products is limited (
Scheme 1a). Lately, Han
et al. [5c] reported the radical cyclization of
N-allylbenzamides with alcohols using di-
tert-butyl peroxide (DTBP) at 120 ℃ (
Scheme 1b). However, the high reaction temperature and single product type of this process have limited its application. In2014, a novelworkwas illustratedby Song, Li and coworkers [5d] to achieve1, 2-carboacylationof
N-arylacrylamides with alcohols in the presence of Fe(OAc)
2 at 110 ℃ (
Scheme 1c).However, the radical cyclization of 1,
n-dienes initiated by
α-C(sp
3)–H functionalization of alcohols in a selective mode has yet to be explored so far. In continuation of our interest in green chemistry [
6], we wish to report a catalyst-free protocol for the radical cyclization of 1, 6-dienes with alcohols using TBPB as an oxidant at relatively low temperature for the selective preparation of 2- pyrrolidinones (
Scheme 1d), which is a crucial class of fivemembered
N-heterocycles commonly found in natural products and pharmaceuticals [
7]. Notably, this discovery included three significant advances: (1) controllable construction of different products (hydroxy-, carbonyl- and acetal-containing 2-pyrrolidinones) from different alcohols under similar conditions; (2) mild reaction conditions: catalyst-free and relatively low temperature at 80 ℃; (3) the realization of two to four bonds forming in one-pot.