123366-97-2Relevant articles and documents
Crucial role of β-elimination in determining regio- and chemoselectivity of the rhodium-catalyzed hydroformylation of N -allylpyrroles: A new approach to 5,6-dihydroindolizines
Settambolo, Roberta
experimental part, p. 2915 - 2921 (2010/10/21)
Rhodium-catalyzed hydroformylation of the chiral (S)-3-alkyl-3-pyrrol-1- ylprop-1-enes at 100 atmospheres total pressure and 25C led to the preferential formation of the branched 3-alkyl-2-methyl-3-pyrrol-1-ylpropanals. At 30 atmospheres and 125°C, the linear 4-alkyl-4-pyrrol-1-ylbutanals were obtained: these aldehydes are not the final products, but evolve into more stable 5,6-dihydroindolizines, with the same optical purity as the starting olefins, via a domino cyclization-dehydration process. According to the generally accepted mechanism for rhodium-catalyzed hydroformylation, the regioselectivity, and then the final chemoselectivity, can be rationalized by taking into account that while at room temperature no -elimination occurs, at high temperature the -elimination involves the branched rhodium-alkyl intermediate only.
Synthesis and Stereoselective Reactions of 2-(Pyrrol-1-yl)alkanals and 2-(pyrrol-1-yl)alkan-1-ones
Kashima, Choji,Maruyama, Tatsuya,Fujioka, Yoko,Harada, Kazuo
, p. 1041 - 1046 (2007/10/02)
2-(2,5-Dimethylpyrrol-1-yl)alkanals, 2-(pyrrol-1-yl)alkanals, and 2-(2,5-dimethylpyrrol-1-yl)alkan-1-ones were prepared.The reactions of these compounds with Grignard and hydride reagents proceeded stereoselectively to give the corresponding 2-(pyrrol-1-yl)alcohols, which were converted into 2-aminoalcohols, such as norephedrine and ephedrine, by cleavage of the pyrrole ring.
