Synthesis of trisubstituted furans via Ag-catalyzed cascade
heterocyclization of 2-(1-alkynyl)-2-alken-1-ones with aryl-amines
Received: 11 August 2017 / Accepted: 13 October 2017 / Published online: 19 October 2017
Ó Institute of Chemistry, Slovak Academy of Sciences 2017
Abstract A silver(I)-catalyzed cascade heterocyclization
of 2-(1-alkynyl)-2-alken-1-ones with aryl-amines is
described to synthesize trisubstituted furans in moderate to
good yields. Tertiary amine is also efﬁcient in this reaction.
This transformation proceeds smoothly with the formation
of C–N or C–C bonds in one-pot with good functional
group tolerance under mild conditions.
Keywords Silver catalyzed Á Trisubstituted furans Á
Cascade reaction Á Cyclization Á Aryl-amine
Transition metal-catalyzed cyclization reactions of carbon–
carbon and carbon–heteroatom bond formation have pro-
ven to be an efﬁcient and straightforward methodology for
the synthesis of cyclic compounds (Patil and Yamamoto
2008; Weibel et al. 2008; Harmata 2010; Yamamoto 2012;
Zeni and Larock 2004; Rubin et al. 2003; Cornil et al.
2015). Generally, silver complexes are considered to have
similar efﬁciency compared with other late transition metal
catalysts and recent studies have shown that silver species
exhibited interesting catalytic activities for C–C, C–N, C–
O, C–P, C–S bond formation (Liu et al. 2015; Hu et al.
2014; Wang et al. 2014; Ji et al. 2009; Hu et al. 2017).
Polysubstituted furans, which is one of the most
important heterocyclic compounds, are not only key
structural units in natural products and pharmaceuticals
(Keay and Dibble 1996; Meegan 1984; Nakanishi 1974)
but also useful intermediates in total syntheses (Wong et al.
1999; Lee et al. 2005). Many efforts have been made to
obtain furan derivatives. (Blanc et al. 2016; Gulevich et al.
2013) Transition metal-catalyzed cyclization of 2-(1-alky-
nyl)-2-alken-1-ones with nucleophiles is one of the typical
approaches to obtain polysubstituted furans since Larock
(Yao et al. 2004) and co-works ﬁrst report in 2004.
Although the cyclization of 2-(1-alkynyl)-2-alken-1-ones
with alcohols (Yao et al. 2004, 2005; Patil et al. 2005),
nitrones (Liu et al. 2009, 2010), alkenes (Liu and Zhang
2011; He et al. 2013a, b; Wang et al. 2015), alkynes (Gao
and Zhang 2012; Zhou et al. 2014), etc. (Xiao and Zhang
2008, 2009; Zhao and Zhang 2010; Li and Zhang 2010;
Gao et al. 2010a, b, 2011; Ghosh et al. 2016) have proven
to be available, the reaction of amines, especially sec-
ondary amines with this enynone was rarely reported (Oh
et al. 2006
; Chen et al. 2011).
Electronic supplementary material The online version of this
article (doi:10.1007/s11696-017-0323-4) contains supplementary
material, which is available to authorized users.
& Ting He
& Yuantao Chen
School of Chemistry and Chemical Engineering, Qinghai
Normal University, Xining 810008, People’s Republic of
Chem. Pap. (2018) 72:691–696