Formal Asymmetric Organocatalytic [3+2] Cyclization between Enecarbamates and 3-Indolylmethanols: Rapid Access to 3-Aminocyclopenta[b]indoles was written by Lebee, Clement;Kataja, Antti O.;Blanchard, Florent;Masson, Geraldine. And the article was included in Chemistry – A European Journal in 2015.Category: chiral-phosphine-ligands This article mentions the following:
A highly enantio- and diastereoselective synthesis of 3-aminocyclopenta[b]indoles I [R1 = Me, Et, CHMe2, cyclopropyl, CH2CHMe(CH2)2CH:CMe2-(S), (CH2)3OSiPh2CMe3, R2 = CH2Ph, R3 = Ph, R4 = R5 = H; R1 = Me, R2 = CMe3, R3 = Ph, R4 = R5 = H; R1 = Me, R2 = CH2Ph, R3 = C6H4F-4, C6H4F-3, C6H4F-2, C6H4CF3-4, C6H4OMe-3, 2-naphthyl, 2-thienyl, CHMe2, Bu, R4 = R5 = H; R1 = Me, R2 = CH2Ph, R3 = Ph, R4 = OMe-5, Br-5, Br-6, R5 = H; R1 = Me, R2 = R5 = CH2Ph, R3 = Ph, R4 = H] has been developed through formal [3+2] cycloaddition reaction of enecarbamates, (E)-R1CH:CHCO2R2, and 3-indolylmethanols, II. This transformation is catalyzed by a chiral phosphoric acid that achieves simultaneous activation of both partners of the cycloaddition Mechanistic data are also presented that suggest that the reaction occurs through a stepwise pathway. In the experiment, the researchers used many compounds, for example, (11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3Category: chiral-phosphine-ligands).
(11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3) belongs to chiral phosphine ligands. Although many reactions require more nucleophilic trialkylphosphines as catalysts, only a few chiral trialkylphosphines are available. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.Category: chiral-phosphine-ligands
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis