“…With the desired (Z)-4-phenylbut-3-yn-2-one O-methyloxime (1a) in hand, we began to investigate various gold catalysts and combinations with silver salts: (PPh 3 )AuCl, (PCy 3 )AuCl, (PhO) 3 PAuCl, AuCl, AuCl 3 , (PPh 3 )AuNTf 2 , (IPr)AuCl (IPr = N,N'-bis(2,6-diisopropylphenyl)imidazol-2-ylidene), along with AgOTf, AgNTf2, or AgSbF6 (Table 1). To our delight, most Au catalysts produced cyclizationoxidative cross-coupling product 4a except (IPr)AuCl (Table 1, entry 18).…”