Chiral N-Allylpyrroles as Versatile Substrates Under Rhodium-Catalyzed Hydroformylation: Good Regio- and Diastereo-Selectivity at Room Temperature and High Pressure

The chiral (S)-3-alkyl-3-(pyrrol-1-yl)prop-1-enes 1a-c were hydroformylated at 20°C and high pressure (100 atm) giving the branched aldehydes 2-methyl-3-(pyrrol-1-yl)alkanales (2+2') with a good regio-selectivity and a high diastereomeric excess (2/2' up to 90:10). The absolute configuration of the diastereomers was assigned via NMR measurements, 2S,3S being the predominant one.