imidazolidinone salts incorporated into the polymer main chain. Main‐chain ionic polyesters functionalized with chiral imidazolidinone salts in the polymer main chain were synthesized by the neutralization polymerization of a chiral imidazolidinone dimer with selected aromatic disulfonic acids. These polyesters were used as heterogeneous organocatalysts in the asymmetric Diels–Alder reaction of trans‐cinnamaldehyde
liquid-supported imidazolidinone catalyst I in enantioselectiveDiels–Alderreactions was investigated. The Diels–Alderreactions involving α,β-unsaturated aldehydes and cyclopentadiene proceeded efficiently in the presence of catalyst I to provide the desired products in moderate to good yields with good to excellent enantioselectivities. Especially noteworthy, catalyst I can be recovered and reused
Novel binaphthyl and biphenyl α- and β-amino acids and esters: organocatalysis of asymmetric Diels–Alder reactions. A combined synthetic and computational study
作者:Philip C. Bulman Page、Francesca S. Kinsey、Yohan Chan、Ian R. Strutt、Alexandra M. Z. Slawin、Garth A. Jones
DOI:10.1039/c8ob01795f
日期:——
aid in the identification of major enantiomers. The calculated product ratios agree well with the experimental data; the transition states identified involve preferential approach of cyclopentene along a trajectory adjacent to the acid/ester group. The four lowest energy transition states display a stabilizing dipolar interaction between the carbonyl group oxygen atom and a terminal proton of the diene
Diarylprolinol Silyl Ether as Catalyst of an <i>exo</i>-Selective, Enantioselective Diels−Alder Reaction
作者:Hiroaki Gotoh、Yujiro Hayashi
DOI:10.1021/ol071009+
日期:2007.7.1
In combined use with CF3CO2H, 2-[bis(3,5-bis-trifluoromethylphenyl) triethylsiloxymethyl]pyrrolidine was found to be an effective organocatalyst of an exo-selective, enantioselectiveDiels-Alderreaction of alpha,beta-unsaturated aldehydes.