4-Fluoro and 4-Hydroxy Pyrrolidine-thioxotetrahydropyrimidinones: Organocatalysts for Green Asymmetric Transformations in Brine
作者:Nikolaos Kaplaneris、Giorgos Koutoulogenis、Marianna Raftopoulou、Christoforos G. Kokotos
DOI:10.1021/acs.joc.5b00283
日期:2015.6.5
The synthesis of both trans- and cis-diastereomers of pyrrolidinine-thioxotetrahydropyrimidinone bearing either a fluorine or a hydroxyl group was accomplished. The new compounds were tested for their catalytic properties in a variety of asymmetric organic transformations and compared with the first generation catalyst. It was found that the new catalysts could efficiently catalyze the reactions in
Chiral anthranilic pyrrolidine as custom-made amine catalyst for enantioselective Michael reaction of nitroalkenes with carbonyl compounds
作者:Yukari Oka、Seiji Tsuzuki、Katsuhiko Moriyama
DOI:10.1039/d1cc04453b
日期:——
pyrrolidine catalyst as a custom-made amine-catalyst was developed for the enantio- and diastereo selective Michael reaction of nitroalkenes with carbonylcompounds. In particular, a peptide-like catalyst in which an α-amino acid is attached to the anthranilic acid skeleton induced the high stereoselectivity of the reaction with aldehydes. Studies of the reaction mechanism indicated that the catalyst exhibits
Novel pyrrolidine-thiohydantoins/thioxotetrahydropyrimidinones as highly effective catalysts for the asymmetric Michael addition
作者:Christoforos G. Kokotos、Dimitris Limnios、Despoina Triggidou、Maria Trifonidou、George Kokotos
DOI:10.1039/c0ob01083a
日期:——
The synthesis of novel organocatalysts consisting of a pyrrolidine moiety and a thiohydantoin or a thioxotetrahydropyrimidinone ring is described. The compound combining the pyrrolidine with the thioxotetrahydropyrimidinone was found to be a highly effective catalyst for the Michael reaction. Low catalyst loadings (1–2.5%) can be employed leading to quantitative yields and excellent stereoselectivities