Fig. 2: Scope of the nucleophiles.

Reaction condition: ^a1a (10 equiv.), 3a (0.3 mmol), Co(acac)₂ (5 mol%), 1,10-Phen (5 mol%), DTBP (3 equiv.), CO (40 bar), ethylene (10 bar), PhCF₃ (0.2 M), 120 ^oC, 20 h. ^b5 equiv. 1a. ^c(R,R)-^tBu-Pybox (5 mol%). ^d5 bar ethylene, 5 bar CO.