Screening different Quatsalts next gave unexpected results, as we found that ammonium salts with non-oxidizable counter anions were cataly:cally ac:ve as well (entry 6), while higher oxida:on state anions (entries 7 and 8) were less-well suited. These results actually suggest that, contrary to our ini:al hypothesis, ammonium salts with (in situ formed) higher oxida:on state counter anions (like (hypo)iodites or tribromides) are not relevant for the herein introduced oxida:ve a-amina:on. Interes:ngly, using well-established Aliquat® 336 18 next, product 2a was obtained straighcorwardly as well (entry 9) and in even higher yield and cleaner manner as compared to the afore tested tetrabutyl ammonium salts. Noteworthy, catalyst loading and reac:on :me could be reduced without compromising yield and conversion (entries 10 and 11). Other oxidants were inves:gated next (entries 12-16) but none of them allowed for any product forma:on, thus illustra:ng the crucial role of the hypochlorite for this process. Aliquat® 336 was also tested in other solvents which allowed us to iden:fy chlorobenzene as the best-suited one (entry 17). 17 Furthermore, NaOCl was found to be a usable oxidant as well (entries 18 and 19). Finally, the yield could be increased further by adding the oxidant in three por:ons (entry 20), thus giving product 2a in high isolated yield (>90%). Table . Op:miza:on of the a-amina:on of b-ketoester 1a using aqueous ammonia under oxida:ve phase-transfer catalysis condi:ons Entry R4N + X -(mol %) Oxidant Solvent t [h] Conv.