“…We thought if dienones or dienals could be prepared by the aerobic γ , δ -dehydrogenation of enones or enals (Scheme 1B). This strategy has two advantages: (1) the precursors, enones or enals, can be obtained readily (some of them are commercially available and they also can be easily synthesized by aldol-like condensations, α -substitution of carbonyl compounds and subsequent elimination, oxidative α , β -dehydrogenation of saturated ketones or aldehydes, and so on) (Wade, 2005, Smith and March, 2001, Nicolaou et al., 2000, Nicolaou et al., 2002, Izawa et al., 2011, Diao and Stahl, 2011, Bigi and White, 2013, Huang and Dong, 2013, Deng et al., 2014, Huang et al., 2015, Jie et al., 2016, Yoshii et al., 2016, Chen et al., 2017) and (2) dienones and dienals bearing substituent groups in various positions could be produced directly. Despite these obvious benefits, to the best our knowledge, the efficient γ , δ -dehydrogenation of enones or enals to produce conjugated dienones or dienals has not been reported so far.…”