Significance: Reactions using the migration of a silyl moiety from carbon to oxygen provide a promising method for the generation of new organometallic species. Here the authors report a new route for making functionalized alkenylcopper reagents, based on a Brook-type rearrangement of acylsilane enolates. The reaction of the resultant organocopper species with electrophiles like alkyl, allyl or aryl halides affords various silyl enol ethers, perfect regiochemistry and exclusively Z-configuration of the double bond. These silyl enone ethers are useful reactive intermediates. All reactions proceed in DMF within several minutes at ambient temperature.Comment: The driving force of the Brook rearrangement is the formation of a highly energetic O-Si bond. However, depending on conditions and the base used, this reaction may follow several routes. The use of t-BuOK instead of t-BuOCu mostly gives products of aryl migration on the keto group from the pentavalent silicon intermediate species. When THF is used as a solvent, C-allylation of the resulting enolate was observed preferentially, as well as in the case of using acyl-TMS species instead of acyltriphenylsilanes. This makes the Brook rearrangement a quite promising process for further investigations.Me Ph 1) t-BuOCu (2 equiv), DMF, 10 min, 25 °C 2) R 2 X [2 equiv, with or without Pd (0) cat.] R 1 = Me, Et, Ph, Bn, etc. R 2 X = All-Cl, MeI, BnBr, alkenyl-I, ArI, etc. up to 78% yield 1) t-BuOCu (2 equiv), DMF, 10 min, 25 °C 2) MeI (2 equiv) 65% yield 1) t-BuOCu (2 equiv), DMF, 10 min, 25 °C 2) CH 2 =C(Me)CH 2 Cl (2 equiv) 61% yield 1) t-BuOCu (2 equiv), DMF, 10 min, 25 °C 2) (E)-HexCH=CHI (2 equiv), Pd(PPh 3 ) 4 (cat.) 65% yield SYNFACTS Contributors: