Discriminating role of bases in diketonate copper(I)-catalyzed C–O couplings: phenol versus diarylether

摘要: The mechanism of the formation phenol from PhI and CsOH catalysed by copper(I) ligated to 1,3-diketonate ket′− generated 2,2,6,6-tetramethyl-3,5-heptanedione (TMHD) has been investigated DFT calculations associated with experimental techniques: cyclic voltammetry, 1H NMR, ESI-MS. Weak halogen bonding between negatively charged O atom [(ket′)CuI–OH]− leads an oxidative addition that gives (ket′)CuIII(Ph)–OH. latter undergoes a faster reductive elimination delivers (ket′)CuI(PhOH) which PhOH is released. PhOPh formed in presence extra base Cs2CO3. two catalytic cycles or are branched at level can either afford be deprotonated Cs2CO3 generate [(ket′)CuI–OPh]−. [(ket′)CuI–OPh]− (ket′)CuIII(Ph)–OPh involved CuI catalyst.