Rh(I)/Sc(OTf)3-co-catalyzed Michael addition of ammonium ylide to (E)-1,4-enediones: synthesis of functionalized 1,4-diketones.

A Rh(I)/Sc(III) co-catalyzed synthesis of highly valuable functionalized 1,4-diketone derivatives in good yields and with an excellent diastereoselectivity. The established method provides a rapid approach to structurally diverse 1,4-diketone scaffold in a very mild and rapid fashion from simple starting materials. Moreover, the protocol could be easily scaled up to gram-scale synthesis. An attempt to develop an asymmetric version of the Rh(I)/guanidine system was also explored, resulting in a moderate enantioselectivity (71% ee).