The computational study on the mechanism of rhodium(I)-catalyzed asymmetric carbonylative [4+1] cycloaddition with (R,R)-Me-DuPHOS-type ligand. A DFT study

The potential energy profile of [Rh((R,R)-Me-DuPHOS)]+-catalyzed asymmetric carbonylative [4+1] cycloaddition of vinylallenes with CO has been studied using a nonlocal density functional method (B3LYP). All the structures have been optimized completely at B3LYP/LANL2DZ level. As illustrated by computation, the intermediate states 4R and 4S are the η4-coordination of a vinylallene and rhodium catalyst. The intermediate states 5R and 5S are bent σ2, π-bonded complexes. The turnover-limiting step for this reaction is the carbonyl insertion reaction leading to the complexes 6. The whole enantioselective carbonylative [4+1] cycloaddition is exothermic. The main product predicted theoretically is (S)-3-cyclopentenone 8S. The calculation results are in good agreement with a worth of experiment investigations.