Rhodium‐Catalyzed Highly Regioselective Hydroformylation‐Hydrogenation of 1,2‐Allenyl‐Phosphine Oxides and ‐Phosphonates

The rhodium‐catalyzed hydroformylation‐hydrogenation of 1,2‐allenyl‐phosphine oxides and ‐phosphonates is reported in this paper. The regioselectivity was well controlled, affording only saturated linear γ‐phosphinyl aldehydes under the standard conditions: (carbonyl)tris(triphenylphosphine)‐rhodium hydride [RhH(CO)(PPh3)3] (3 mol%), triphenylphosphine (PPh3) (10 mol%), carbon monoxide (CO) (2.4×106 Pa), hydrogen (H2) (subsequently charged to 4.8×106 Pa), toluene, 100 °C, 24 h.