(Mac‐SILC) in the pores of silica gel with the aid of an ionic liquid – 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide. The heterogenized organocatalyst was utilized for the enantioselectiveDiels–Alder reaction of cyclopentadiene and cinnamaldehyde, recovered by simple filtration and subsequent evacuation, and repeatedly used up to six times in 81% average chemical yield, 87% ee for endo‐
Catalysis of Diels-Alder reactions by metalloporphyrins
作者:David W. Bartley、Thomas J. Kodadek
DOI:10.1016/s0040-4039(00)97048-5
日期:1990.1
Aluminium (111) tetraphenyl porphyrin chloride (AITPPCl) has been shown to catalyze Diels-Alder reactions of α,β-unsaturated carbonyl compounds in moderate yield. Selectivity based on electronic effects is exhibited which is different from that seen with catalysts such as diethylaluminlum chloride.
Ruthenium<i>Lewis</i>Acid-Catalyzed Asymmetric<i>Diels-Alder</i>Reactions: Reverse-Face Selectivity for<i>α</i>,<i>β</i>-Unsaturated Aldehydes and Ketones
作者:Sirinporn Thamapipol、Bettina Ludwig、Céline Besnard、Christophe Saudan、E. Peter Kündig
DOI:10.1002/hlca.201600139
日期:2016.10
Acrolein, methacrolein, methylvinylketone, ethyl vinylketone, 3‐methyl‐3‐en‐2‐one, and divinyl ketone were coordinated to a cationic cyclopentadienyl ruthenium(II) Lewis acid incorporating the electron‐poor bidentate BIPHOP–F ligand. Analysis by NOESY and ROESY NMR techniques allowed the determination of conformations of enals and enones present in solution in CD2Cl2. The results were compared to
An in-depth look at the effect of Lewis acid catalysts on Diels–Alder cycloadditions in ionic liquids
作者:Guadalupe Silvero、María José Arévalo、José Luis Bravo、Martín Ávalos、José Luis Jiménez、Ignacio López
DOI:10.1016/j.tet.2005.05.064
日期:2005.7
The present work explores in detail the Diels–Alderreaction between cyclopentadiene and a series of dienophiles, performed in an innovative medium such as an ionicliquid. The potential activation of differentLewisacid catalysts and their load effect when used in combination with this solvent have been explored, in order to settle the improvement on rates and selectivities.
Design of Chiral <i>N</i>-Triflyl Phosphoramide as a Strong Chiral Brønsted Acid and Its Application to Asymmetric Diels−Alder Reaction
作者:Daisuke Nakashima、Hisashi Yamamoto
DOI:10.1021/ja062508t
日期:2006.8.1
A highly reactive and acidic chiral Brønsted acid catalyst, chiral N-triflyl phosphoramide, was developed. Highly enantioselective Diels-Alderreaction of alpha,beta-unsaturated ketone with silyloxydiene was demonstrated using this chiral Brønsted acid catalyst.