Table 1.

Silyl Addition to an Acyclic Dienone: NHC–Cu Screening^a

entry	imidazolinium salt	conv (%)b	yield (%)c	erd
1	4a	80	77	86:14
2	4b	>98	92	93:7
3	4c	88	87	91:9
4	5	94	91	96:4
5	6a	>98	94	95:5
6	6b	>98	96	99:1

^aReactions performed under N₂ atm.

^bDetermined by analysis of 400 MHz ¹H NMR spectra of unpurified mixtures (±2%).

^cYields of purified products (±5%).

^dDetermined by HPLC analysis. See the Supporting Information (SI) for details. Mes = 2,4,6-Me₃C₆H₂.