Synthesis of oxindole derivatives from N‐alkenyl‐o‐chloroanilides with zero‐valent nickel complex

Oxindole derivatives have been obtained from N‐alkenyl‐o‐chloroanilides by reaction with tetrakis(triphenylphosphine)nickel(0) in toluene as solvent in good yields. A detailed analysis of all the products of the reaction allows to confirm the postulated mechanism of the cyclization reaction. The o‐chloroanilides of the 3‐cyclohexenylacetic acid fails in the cyclization reaction, since the torsional hindrance seems to avoid that the endocyclic double bond may be orthogonally to the ortho‐σ‐nickel complex intermediate on the aromatic ring.