A Direct CH/ArH Coupling Approach to Oxindoles, Thio‐oxindoles, 3,4‐Dihydro‐1 H‐quinolin‐2‐ones, and 1,2,3,4‐Tetrahydroquinolines

Abstract A copper(II)‐catalysed approach to oxindoles, thio‐oxindoles, 3,4‐dihydro‐1 H ‐quinolin‐2‐ones, and 1,2,3,4‐tetrahydroquinolines via formal CH, ArH coupling is described. In a new variant, copper(II) 2‐ethylhexanoate has been identified as an inexpensive and efficient catalyst for this transformation, which utilises atmospheric oxygen as the re‐oxidant.