Amine-catalyzed [2 + 2 + 2] and [2 + 4] annulations of Morita–Baylis–Hillman (MBH) acetates with cyano activated alkenes and 1,3-azadienes have been developed to provide cyclohexanes and tetrahydropyridines. In the annulations, MBH acetates serve as a novel C2 component with an inactive homoallylic methyl involved in the bond formation.
![Graphical abstract: Distinct reactivity of Morita–Baylis–Hillman acetates as a novel C2 component in amine-catalyzed [2 + 2 + 2] and [2 + 4] annulations](http://hg.y866.cn/compound/lib/scimg/usr/1/C3CC41419A.jpg)
